├── .gitignore ├── .idea ├── .gitignore ├── vcs.xml └── $PRODUCT_WORKSPACE_FILE$ ├── .settings ├── org.eclipse.wst.jsdt.ui.superType.name ├── org.eclipse.wst.validation.prefs ├── org.eclipse.wst.jsdt.ui.superType.container ├── org.eclipse.m2e.core.prefs ├── org.eclipse.wst.common.project.facet.core.prefs.xml ├── org.eclipse.wst.common.project.facet.core.xml ├── .jsdtscope └── org.eclipse.wst.common.component ├── src └── main │ ├── java │ └── com │ │ └── javaprogramto │ │ ├── files │ │ ├── readonlywrite │ │ │ ├── make-new-file.txt │ │ │ ├── make-read-only.txt │ │ │ └── FileSetWritableExample.java │ │ ├── read │ │ │ ├── student.txt │ │ │ └── student.csv │ │ ├── directory │ │ │ ├── CurrentDirectorySystemGetpropertyExample.java │ │ │ ├── CurrentDirectoryPathGetExample.java │ │ │ └── CurrentDirectoryFileSystemsExample.java │ │ └── printwriter │ │ │ ├── newline │ │ │ ├── PrintWriterNewLine2.java │ │ │ └── PrintWriterNewLine.java │ │ │ ├── PrintWriterExample1.java │ │ │ └── tofile │ │ │ ├── PrintWriterToFileExample1.java │ │ │ ├── PrintWriterToFileExample2.java │ │ │ └── PrintWriterToFileExample3.java │ │ ├── java8 │ │ ├── nashorn │ │ │ ├── hello.js │ │ │ ├── hashmap.js │ │ │ └── sample.js │ │ ├── dates │ │ │ ├── timestamp │ │ │ │ ├── CurrentTimestampExample5.java │ │ │ │ ├── CurrentTimestampExample2.java │ │ │ │ ├── CurrentTimestampExample1.java │ │ │ │ ├── CurrentTimestampExample4.java │ │ │ │ ├── CurrentTimestampExample3.java │ │ │ │ ├── CurrentTimestampExample7.java │ │ │ │ └── CurrentTimestampExample6.java │ │ │ ├── getdatetime │ │ │ │ ├── SqlDateExample.java │ │ │ │ ├── ClockExample.java │ │ │ │ ├── LocalTimeExample.java │ │ │ │ ├── LocalDateTimeExample.java │ │ │ │ ├── LocalDateExample.java │ │ │ │ ├── ZonedDateTimeExample.java │ │ │ │ ├── CalendarExample.java │ │ │ │ ├── DateExample.java │ │ │ │ └── SimpleDateFormatExample.java │ │ │ ├── instant │ │ │ │ ├── InstantCreationExample.java │ │ │ │ ├── InstantParseExample.java │ │ │ │ └── InstantEpochSecondExample.java │ │ │ ├── localdate │ │ │ │ ├── LocalDateCreation.java │ │ │ │ ├── StringToLocalDateExample.java │ │ │ │ ├── AddingDaysExample.java │ │ │ │ └── LocalDateAtTimeExample.java │ │ │ ├── conversion │ │ │ │ ├── sql │ │ │ │ │ └── SQLDateToLocalDateExample.java │ │ │ │ ├── totimestamp │ │ │ │ │ ├── LocalDateToTimeStampExample.java │ │ │ │ │ └── LocalDateTimeToTimeStampExample.java │ │ │ │ └── CalenderToLocalDateExample.java │ │ │ ├── localdatetime │ │ │ │ └── LocalDateTimeCreationExample.java │ │ │ ├── datetimeformatter │ │ │ │ ├── DateTimeFormatterFormatStyleExample.java │ │ │ │ └── DateTimeFormatterFormatStyleExample23.java │ │ │ ├── format │ │ │ │ └── FormatTIme24HoursExample.java │ │ │ ├── zoneddatetime │ │ │ │ └── GetTimezoneExample.java │ │ │ └── currentdate │ │ │ │ └── CurrentTimeStamp.java │ │ ├── optional │ │ │ ├── OptionalOrElseThrowExample.java │ │ │ ├── OptionalIsPresent.java │ │ │ ├── OptionalFilterExample.java │ │ │ ├── OptionalIfPresentExample.java │ │ │ ├── OptionalOrElse.java │ │ │ ├── OptionalflatmapExample.java │ │ │ ├── OptionalOrElseGet.java │ │ │ ├── OfNullableExample.java │ │ │ ├── OptionalIsEmpty.java │ │ │ └── OptionalGetExample.java │ │ ├── intstream │ │ │ ├── toarray │ │ │ │ └── IntStreamToArrayExample.java │ │ │ └── toList │ │ │ │ └── IntStreamToListExample2.java │ │ ├── streams │ │ │ ├── foreach │ │ │ │ ├── StreamFilterBreak.java │ │ │ │ ├── StreamTakeWhile.java │ │ │ │ └── StreamForBreak.java │ │ │ ├── reduce │ │ │ │ ├── StreamReduceExample2.java │ │ │ │ ├── StreamReduceExample.java │ │ │ │ └── StreamReduceExample7.java │ │ │ ├── optionals │ │ │ │ └── returntype │ │ │ │ │ └── Employee.java │ │ │ ├── filter │ │ │ │ ├── FilterExample.java │ │ │ │ ├── ifelse │ │ │ │ │ └── Java8StreammultipleIfExample.java │ │ │ │ └── ThrowingFunctionExample.java │ │ │ ├── infinite │ │ │ │ ├── StreamIterateExample.java │ │ │ │ └── StreamGenerateExample.java │ │ │ ├── parallel │ │ │ │ └── streams │ │ │ │ │ └── ParallelStreamCreation.java │ │ │ └── find │ │ │ │ ├── FindAnyExample.java │ │ │ │ └── FindAnyParallelStreamExample.java │ │ ├── integer │ │ │ ├── IntegerHashcodeExample.java │ │ │ ├── IntegerToUnsignedLongExample.java │ │ │ └── IntegerCompareUnsignedExample.java │ │ ├── foreach │ │ │ ├── Java8ForEachListAddExample.java │ │ │ ├── NormalForEachExample.java │ │ │ └── NormalForEachListExample.java │ │ ├── arraylist │ │ │ ├── ArrayListMaxSizeExample.java │ │ │ └── ArrayListMaxSizeExample2.java │ │ ├── iterate │ │ │ ├── IterateForEachExample.java │ │ │ └── SplitIteratorForEachRemainingExample.java │ │ ├── comparator │ │ │ └── reverse │ │ │ │ ├── ComparatorReverse.java │ │ │ │ └── ComparatorReverse2.java │ │ ├── collectors │ │ │ └── tolist │ │ │ │ ├── StreamCollectToListExample1.java │ │ │ │ ├── StreamCollectToListExample5.java │ │ │ │ └── StreamCollectToListExample2.java │ │ ├── anymatch │ │ │ ├── AnyMatchOnEmptyStream.java │ │ │ └── AnyMatchEvenExample.java │ │ ├── skip │ │ │ ├── Skip10ValuesExample.java │ │ │ ├── SkipNegativeIndexExample.java │ │ │ └── Skip5EvenNumbersExample.java │ │ ├── maptolist │ │ │ ├── MapKeysToListExample.java │ │ │ └── MapValuesToListExample.java │ │ ├── functional │ │ │ └── interfaces │ │ │ │ └── function │ │ │ │ └── java8FunctionExample.java │ │ └── concat │ │ │ └── StreamConcatException.java │ │ ├── design │ │ └── patterns │ │ │ └── strategy1 │ │ │ ├── strategy │ │ │ └── IBaseOperation.java │ │ │ ├── algorithms │ │ │ ├── AdditionOperation.java │ │ │ ├── DivisionOperation.java │ │ │ ├── SubtractionOperation.java │ │ │ └── MultiplicationOperation.java │ │ │ ├── context │ │ │ └── OperationContext.java │ │ │ └── test │ │ │ └── TestCalculationStrategy.java │ │ ├── arrays │ │ ├── print │ │ │ ├── PrintArray.java │ │ │ ├── PrintArrays.java │ │ │ └── PrintMultiDimenstionalArray.java │ │ ├── booleanarray │ │ │ ├── BooleanArrayExample.java │ │ │ ├── BooleanArrayExample4.java │ │ │ ├── BooleanArrayExample6.java │ │ │ ├── BooleanArrayExample2.java │ │ │ └── BooleanArrayExample5.java │ │ ├── initialize │ │ │ ├── ArrayDeclaration.java │ │ │ └── ArrayInitializationDefaultValues.java │ │ ├── setall │ │ │ ├── IntArraySetAllExample.java │ │ │ ├── LongArraySetAllExample.java │ │ │ ├── DoubleArraySetAllExample.java │ │ │ └── StringArraySetAllExample.java │ │ ├── returns │ │ │ ├── ArrayReturnExample1.java │ │ │ └── ArrayReturnExample4.java │ │ ├── toiterabale │ │ │ └── ArrayIterate.java │ │ ├── empty │ │ │ ├── ReturnEmptyArrayExample1.java │ │ │ ├── ReturnEmptyArrayExample2.java │ │ │ └── ReturnEmptyArrayExample3.java │ │ ├── multidimensional │ │ │ ├── NestedArraysExample1.java │ │ │ └── NestedArraysExample2.java │ │ ├── bytearray │ │ │ ├── Base64Decode.java │ │ │ ├── Base64Encode.java │ │ │ ├── CharsetDecode.java │ │ │ └── CharsetEncode.java │ │ ├── find │ │ │ └── LinearSearch.java │ │ ├── sort │ │ │ └── reverse │ │ │ │ ├── ArraySortReverseInts.java │ │ │ │ └── ArraySortReverseStrings.java │ │ └── add │ │ │ └── JavaArrayToAddExample2.java │ │ ├── programs │ │ ├── escape │ │ │ ├── EscapeSlashNExample.java │ │ │ ├── EscapeSlashTExample3.java │ │ │ ├── EscapeSlashNExample2.java │ │ │ ├── newline │ │ │ │ ├── AddNewLineExample5.java │ │ │ │ ├── AddNewLineExample1.java │ │ │ │ ├── AddNewLineExample2.java │ │ │ │ ├── AddNewLineExample3.java │ │ │ │ ├── AddNewLineExample6.java │ │ │ │ └── AddNewLineExample4.java │ │ │ ├── EscapeSlashTExample4.java │ │ │ └── sequences │ │ │ │ └── EscapeSequencesExample1.java │ │ ├── strings │ │ │ ├── tolong │ │ │ │ ├── StringToLongExample4.java │ │ │ │ ├── StringToLongExample3.java │ │ │ │ ├── StringToLongExample2.java │ │ │ │ └── StringToLongExample.java │ │ │ ├── todouble │ │ │ │ ├── StringToDoubleExample4.java │ │ │ │ ├── StringToDoubleExample1.java │ │ │ │ ├── StringToDoubleExample2.java │ │ │ │ ├── StringToDoubleExample3.java │ │ │ │ └── decimal │ │ │ │ │ └── StringToDoubleDecimalsPlaces2.java │ │ │ ├── count │ │ │ │ ├── CountNoCharStreamExample3.java │ │ │ │ ├── CountNoCharStreamExample4.java │ │ │ │ ├── CountNoCharExample1.java │ │ │ │ └── CountNoCharExample2.java │ │ │ ├── remove │ │ │ │ ├── character │ │ │ │ │ ├── StringRemoveCharacterExample.java │ │ │ │ │ ├── StringRemoveCharacterExample2.java │ │ │ │ │ ├── StringRemoveCharacterExample5.java │ │ │ │ │ ├── StringRemoveCharacterExample4.java │ │ │ │ │ └── StringRemoveCharacterExample3.java │ │ │ │ └── duplicates │ │ │ │ │ ├── StringRemoveDuplicatesExample3.java │ │ │ │ │ └── StringRemoveDuplicatesExample1.java │ │ │ ├── permutations │ │ │ │ ├── StringPermutationsExample1.java │ │ │ │ └── StringPermutationsExample2.java │ │ │ ├── substring │ │ │ │ ├── count │ │ │ │ │ └── SubstringCountExample.java │ │ │ │ └── StringContainsSubstringExample2.java │ │ │ ├── joining │ │ │ │ └── JoiningStringDelimiterExample3.java │ │ │ ├── palindrome │ │ │ │ └── StringCheckPalindrome3.java │ │ │ └── tofloat │ │ │ │ ├── StringToFloatExample1.java │ │ │ │ └── StringToFloatExample2.java │ │ ├── exit │ │ │ ├── JavaProgramExitExample2.java │ │ │ ├── JavaProgramExitExample.java │ │ │ ├── JavaProgramExitExample3.java │ │ │ └── JavaProgramExitExample4.java │ │ ├── infinite │ │ │ └── loops │ │ │ │ ├── DoWhileLoopInfiniteExample.java │ │ │ │ ├── ForLoopInfiniteExample.java │ │ │ │ └── WhileLoopInfiniteExample.java │ │ ├── characters │ │ │ ├── PrintLowerCaseAlphabets.java │ │ │ ├── PrintUpperCaseAlphabets.java │ │ │ └── IfElseVowel.java │ │ ├── maths │ │ │ ├── MultiplyFloatingNumbers.java │ │ │ ├── LCMOfLargeNumbers.java │ │ │ ├── QuotientRemainderExample.java │ │ │ └── LCMFromGCDExample.java │ │ ├── count │ │ │ ├── CountDigitsMathLog10Example.java │ │ │ ├── CountDigitsIntegerToStringExample.java │ │ │ └── CountDigitsIterativeExample.java │ │ ├── large │ │ │ ├── Largest3NumbersOptimizedExample2.java │ │ │ ├── Largest3NumbersOptimizedExample1.java │ │ │ ├── Largest3NumbersExample1.java │ │ │ └── Largest3NumbersNestedIfExample.java │ │ ├── scanner │ │ │ └── close │ │ │ │ ├── ScannerCloseExample1.java │ │ │ │ └── ScannerCloseExample4.java │ │ ├── numbers │ │ │ ├── math │ │ │ │ ├── MathAbsoluteExample1.java │ │ │ │ ├── MathAbsoluteExample2.java │ │ │ │ ├── MathAbsoluteExample4.java │ │ │ │ └── MathAbsoluteExample3.java │ │ │ ├── NumberPowerMathPowExample.java │ │ │ ├── NumberPowerForLoopExample.java │ │ │ └── NumberPowerWhileLoopExample.java │ │ ├── conversions │ │ │ └── string │ │ │ │ ├── StringtoStringArraySplit.java │ │ │ │ └── StringtoStringArraySplitRegularExpression.java │ │ ├── arrays │ │ │ ├── average │ │ │ │ └── ArrayAverage.java │ │ │ └── search │ │ │ │ ├── FIndValue.java │ │ │ │ ├── IntStreamFindValue.java │ │ │ │ └── IntStreamFindStringValue.java │ │ └── MultiplicationTableForLoop.java │ │ ├── exception │ │ ├── custom │ │ │ └── checked │ │ │ │ ├── InvalidFileNamePatternException.java │ │ │ │ └── InvalidFileNamePatternException2.java │ │ ├── classcaseexception │ │ │ ├── ClassCastExceptionExample.java │ │ │ ├── ClassCastExceptionExample3.java │ │ │ └── ClassCastExceptionExample2.java │ │ ├── IllegalArgumentException │ │ │ ├── IllegalArgumentExceptionExample.java │ │ │ ├── IllegalArgumentExceptionExample2.java │ │ │ └── IllegalArgumentExceptionExample3.java │ │ ├── inputmismatchexception │ │ │ ├── InputMismatchExceptionExample.java │ │ │ └── InputMismatchExceptionExample2.java │ │ └── FinallyBlockAfterReturn.java │ │ ├── keywords │ │ ├── finals │ │ │ ├── FinalClassExample.java │ │ │ ├── FInalVaraibleExamples2.java │ │ │ ├── FInalVaraibleExamples4.java │ │ │ ├── Customer.java │ │ │ ├── FInalVaraibleExamples3.java │ │ │ └── FInalVaraibleExamples.java │ │ └── extend │ │ │ ├── InterfaceExtendsExamples.java │ │ │ ├── ClasesExtendsExamples.java │ │ │ └── FinalClasesExtendsExamples.java │ │ ├── strings │ │ ├── split │ │ │ ├── StringSplitExample1.java │ │ │ ├── StringSplitExample4.java │ │ │ ├── StringSplitExample2.java │ │ │ ├── StringSplitExample3.java │ │ │ ├── StringSplitExample5.java │ │ │ ├── StringSplitExample6.java │ │ │ ├── StringSplitExample7.java │ │ │ ├── StringSplitExampleWithSlash.java │ │ │ └── StringSplitLimitExample3.java │ │ ├── StringsubSequenceWithNegativeExample.java │ │ ├── StringReplaceFirstExample.java │ │ ├── StringStartsWithCaseSensitiveExample.java │ │ ├── StringCodepointBeforeException.java │ │ ├── StringReplaceFirstPatternSyntaxException.java │ │ ├── StringReplaceFirstSpecialCharsExample.java │ │ ├── mix │ │ │ ├── StringsConcatenateExample1.java │ │ │ ├── StringsConcatenateExample2.java │ │ │ └── StringsConcatenateExample3.java │ │ ├── StringsubSequenceExample.java │ │ ├── StringHashcodeExample.java │ │ ├── StringCodepoinExampleToConvertStream.java │ │ ├── StringCodepointCountExample.java │ │ ├── StringCodepointCountException.java │ │ ├── StringStartsWithExample.java │ │ ├── StringCodepointBeforeExample.java │ │ ├── compare │ │ │ └── StringDoesnotEqual.java │ │ ├── StringStartsWithIndexExample.java │ │ └── StringHashcodeCheckExample.java │ │ ├── collections │ │ ├── generics │ │ │ ├── GenericsCompileTimeError.java │ │ │ ├── GenericsCompileTimeErrorFix.java │ │ │ ├── GenericsCompileTimeError2Fix.java │ │ │ └── GenericsCompileTimeError2.java │ │ ├── hashmap │ │ │ └── print │ │ │ │ ├── HashMapPrintExample1.java │ │ │ │ ├── HashMapPrintExample3.java │ │ │ │ ├── HashMapPrintExample4.java │ │ │ │ ├── HashMapPrintExample2.java │ │ │ │ └── HashMapPrintExample5.java │ │ ├── set │ │ │ └── add │ │ │ │ ├── TreeSetAddExample.java │ │ │ │ ├── HashSetAddExample.java │ │ │ │ └── LinkedHashSetAddExample.java │ │ └── treemap │ │ │ └── comparator │ │ │ └── TreeMapComparatorExample.java │ │ ├── numbers │ │ └── swap │ │ │ ├── SwapNumbersTemp.java │ │ │ └── SwapNumbersWIthoutThirdVariable.java │ │ ├── w3schools │ │ └── programs │ │ │ ├── string │ │ │ ├── StringToLowercaseLocale.java │ │ │ ├── StringSubStringExample.java │ │ │ └── StringSubEndIndexStringExample.java │ │ │ └── ascii │ │ │ ├── StringToAscii.java │ │ │ ├── StringToAsciiByteCasting.java │ │ │ └── StringToAsciiUSBytes.java │ │ ├── java11 │ │ └── shebang │ │ │ ├── batch-job.sh │ │ │ └── BatchJob.java │ │ ├── datatypes │ │ └── diff │ │ │ ├── FloatVsDoubleDataLoss.java │ │ │ ├── FloatVsDoubleDefault.java │ │ │ └── FloatVsDoublePrecision.java │ │ ├── chars │ │ ├── AddCharToStringExample.java │ │ ├── AddCharToStringExample2.java │ │ └── AddCharToStringExample4.java │ │ ├── threads │ │ ├── AnonymousRunnableThread.java │ │ ├── AnonymousThreadExample.java │ │ ├── delay │ │ │ ├── DelayWithExecutorService.java │ │ │ └── DelayWithThreadSleep.java │ │ └── AnonymousRunnableExample.java │ │ └── convert │ │ ├── string │ │ └── toint │ │ │ └── StringToIntException.java │ │ └── chartostring │ │ └── CharToStringExample3.java │ ├── resources │ ├── META-INF │ │ └── microprofile-config.properties │ ├── print_writer │ │ ├── test.txt │ │ ├── test2.txt │ │ └── file │ │ │ └── test2.txt │ ├── book.json │ ├── logging.properties │ └── dummy.txt │ ├── webapp │ └── WEB-INF │ │ └── beans.xml │ └── main.iml ├── Dockerfile └── README.md /.gitignore: -------------------------------------------------------------------------------- 1 | /target/ 2 | -------------------------------------------------------------------------------- /.idea/.gitignore: -------------------------------------------------------------------------------- 1 | # Default ignored files 2 | /workspace.xml -------------------------------------------------------------------------------- /.settings/org.eclipse.wst.jsdt.ui.superType.name: -------------------------------------------------------------------------------- 1 | Window -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/files/readonlywrite/make-new-file.txt: -------------------------------------------------------------------------------- 1 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/files/readonlywrite/make-read-only.txt: -------------------------------------------------------------------------------- 1 | -------------------------------------------------------------------------------- /src/main/resources/META-INF/microprofile-config.properties: -------------------------------------------------------------------------------- 1 | message=Enjoy -------------------------------------------------------------------------------- /src/main/resources/print_writer/test.txt: -------------------------------------------------------------------------------- 1 | First line in file Second line in file -------------------------------------------------------------------------------- /src/main/resources/print_writer/test2.txt: -------------------------------------------------------------------------------- 1 | Line 1 2 | Line 2 3 | Line 3 4 | -------------------------------------------------------------------------------- /src/main/resources/print_writer/file/test2.txt: -------------------------------------------------------------------------------- 1 | Line 1 2 | Line 2 3 | Line 3 4 | -------------------------------------------------------------------------------- /Dockerfile: -------------------------------------------------------------------------------- 1 | FROM airhacks/glassfish 2 | COPY ./target/corejav.war ${DEPLOYMENT_DIR} 3 | -------------------------------------------------------------------------------- /.settings/org.eclipse.wst.validation.prefs: -------------------------------------------------------------------------------- 1 | disabled=06target 2 | eclipse.preferences.version=1 3 | -------------------------------------------------------------------------------- /.settings/org.eclipse.wst.jsdt.ui.superType.container: -------------------------------------------------------------------------------- 1 | org.eclipse.wst.jsdt.launching.baseBrowserLibrary -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/files/read/student.txt: -------------------------------------------------------------------------------- 1 | student name - Java Learner 2 | Location - India -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/files/read/student.csv: -------------------------------------------------------------------------------- 1 | student id,name,age 2 | 100,Jhon,30 3 | 101,Shella,35 4 | 102,Dhon,40 -------------------------------------------------------------------------------- /.settings/org.eclipse.m2e.core.prefs: -------------------------------------------------------------------------------- 1 | activeProfiles= 2 | eclipse.preferences.version=1 3 | resolveWorkspaceProjects=true 4 | version=1 5 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/nashorn/hello.js: -------------------------------------------------------------------------------- 1 | #!$JAVA_HOME/bin/jjs 2 | var greeting = "Hello World, Welcome"; 3 | print(greeting); -------------------------------------------------------------------------------- /src/main/resources/book.json: -------------------------------------------------------------------------------- 1 | { 2 | "id": "100", 3 | "title": "Java Program To Blog", 4 | "pages": "500", 5 | "timeReleased": "2019-11-09" 6 | } -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/nashorn/hashmap.js: -------------------------------------------------------------------------------- 1 | var HashMap = Java.type('java.util.HashMap') 2 | var map = new HashMap() 3 | map.put('hello', 'world') 4 | print("map values : "+map) 5 | -------------------------------------------------------------------------------- /.idea/vcs.xml: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # Build 2 | mvn clean package && docker build -t com.javaprogramtto/corejav . 3 | 4 | # RUN 5 | 6 | docker rm -f corejav || true && docker run -d -p 8080:8080 -p 4848:4848 --name corejav com.javaprogramtto/corejav -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/design/patterns/strategy1/strategy/IBaseOperation.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.design.patterns.strategy1.strategy; 2 | 3 | public interface IBaseOperation { 4 | 5 | int doOperation(int value1, int value2); 6 | } 7 | -------------------------------------------------------------------------------- /src/main/resources/logging.properties: -------------------------------------------------------------------------------- 1 | handlers= java.util.logging.ConsoleHandler 2 | .level= INFO 3 | java.util.logging.ConsoleHandler.level = INFO 4 | java.util.logging.ConsoleHandler.formatter = java.util.logging.SimpleFormatter 5 | 6 | com.javaprogramto.logging.level=INFO 7 | -------------------------------------------------------------------------------- /src/main/resources/dummy.txt: -------------------------------------------------------------------------------- 1 | Line 1 : Hello Reader 2 | Line 2 : Welcome to the java programt to . com blog 3 | Line 3 : Here you find the articles on the java concepts 4 | Line 4 : This is example to read this file line by line 5 | Line 5 : Let us see the examples on Java 8 Streams API. -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/print/PrintArray.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.print; 2 | 3 | public class PrintArray { 4 | public static void main(String[] args) { 5 | 6 | int[] array = { 1, 2, 3, 4, 5, 6, 7 }; 7 | 8 | for (int value : array) { 9 | System.out.println(value); 10 | } 11 | 12 | } 13 | } 14 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/escape/EscapeSlashNExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.escape; 2 | 3 | public class EscapeSlashNExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | String s1 = "java"; 8 | String s2 = "programs"; 9 | 10 | System.out.println(s1 + "\n" + s2); 11 | } 12 | } 13 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/escape/EscapeSlashTExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.escape; 2 | 3 | public class EscapeSlashTExample3 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String s1 = "java"; 8 | String s2 = "programs"; 9 | 10 | System.out.println(s1 + "\t" + s2); 11 | } 12 | } 13 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/exception/custom/checked/InvalidFileNamePatternException.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.exception.custom.checked; 2 | 3 | public class InvalidFileNamePatternException extends Exception { 4 | 5 | public InvalidFileNamePatternException(String reason, Throwable t) { 6 | super(reason, t); 7 | } 8 | 9 | } 10 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/exception/custom/checked/InvalidFileNamePatternException2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.exception.custom.checked; 2 | 3 | public class InvalidFileNamePatternException2 extends RuntimeException { 4 | 5 | public InvalidFileNamePatternException2(String reason, Throwable t) { 6 | super(reason, t); 7 | } 8 | 9 | } 10 | -------------------------------------------------------------------------------- /src/main/webapp/WEB-INF/beans.xml: -------------------------------------------------------------------------------- 1 | 2 | 6 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/escape/EscapeSlashNExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.escape; 2 | 3 | public class EscapeSlashNExample2 { 4 | 5 | public static void main(String[] args) { 6 | 7 | System.out.println("hello world \n welcome"); 8 | 9 | System.out.println("how \n are \n you \n doing \n ?"); 10 | 11 | } 12 | 13 | } 14 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/booleanarray/BooleanArrayExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.booleanarray; 2 | 3 | public class BooleanArrayExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | boolean[] array1 = {}; 8 | 9 | boolean[] array2 = { false, true, true }; 10 | 11 | boolean[] array3 = new boolean[5]; 12 | } 13 | } 14 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/exception/classcaseexception/ClassCastExceptionExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.exception.classcaseexception; 2 | 3 | public class ClassCastExceptionExample { 4 | 5 | public static void main(String[] args) { 6 | C a = new C(); 7 | B b = (B) a; 8 | } 9 | } 10 | 11 | class A { 12 | 13 | } 14 | 15 | class B extends C { 16 | 17 | } -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/print/PrintArrays.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.print; 2 | 3 | import java.util.Arrays; 4 | 5 | public class PrintArrays { 6 | 7 | public static void main(String[] args) { 8 | int[] values = { 10, 20, 30, 40, 50 }; 9 | 10 | String value = Arrays.toString(values); 11 | System.out.println(value); 12 | 13 | } 14 | 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/timestamp/CurrentTimestampExample5.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.timestamp; 2 | 3 | import java.time.Instant; 4 | 5 | public class CurrentTimestampExample5 { 6 | 7 | public static void main(String[] args) { 8 | 9 | Instant instant = Instant.now(); 10 | 11 | System.out.println("timestamp now : " + instant); 12 | } 13 | 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/tolong/StringToLongExample4.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.tolong; 2 | 3 | public class StringToLongExample4 { 4 | 5 | public static void main(String[] args) { 6 | 7 | long one = Long.parseLong("abc133"); 8 | 9 | Long two = Long.valueOf("abc133"); 10 | 11 | Long three = new Long("abc133"); 12 | 13 | 14 | } 15 | 16 | } 17 | -------------------------------------------------------------------------------- /.settings/org.eclipse.wst.common.project.facet.core.prefs.xml: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | -------------------------------------------------------------------------------- /.settings/org.eclipse.wst.common.project.facet.core.xml: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/keywords/finals/FinalClassExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.keywords.finals; 2 | 3 | public class FinalClassExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | 8 | } 9 | } 10 | 11 | final class Java { 12 | 13 | public void sayHelloWorld() { 14 | System.out.println("hello world"); 15 | } 16 | } 17 | /* 18 | class JavaProgamTo extends Java { 19 | 20 | } 21 | */ -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/keywords/finals/FInalVaraibleExamples2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.keywords.finals; 2 | 3 | public class FInalVaraibleExamples2 { 4 | 5 | public static void main(String[] args) { 6 | 7 | // final local variable with no value assigned at the time of declaration 8 | final int j; 9 | int i = 20; 10 | 11 | j = 20; 12 | System.out.println("final j = " + j); 13 | } 14 | 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/exit/JavaProgramExitExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.exit; 2 | 3 | public class JavaProgramExitExample2 { 4 | 5 | public static void main(String[] args) { 6 | 7 | System.out.println("satement 1"); 8 | System.out.println("statement before return statement"); 9 | 10 | return; 11 | 12 | System.out.println("Last line from this program"); 13 | } 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/split/StringSplitExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings.split; 2 | 3 | public class StringSplitExample1 { 4 | 5 | public static void main(String[] args) { 6 | String str = "java@program@to.com"; 7 | 8 | String[] splitArray = str.split("@"); 9 | 10 | for(String value : splitArray){ 11 | System.out.println(value); 12 | } 13 | } 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/collections/generics/GenericsCompileTimeError.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.collections.generics; 2 | 3 | import java.util.ArrayList; 4 | import java.util.List; 5 | 6 | public class GenericsCompileTimeError { 7 | 8 | public static void main(String[] args) { 9 | 10 | List integers = null; 11 | 12 | // uncomment to see the error 13 | //integers = new ArrayList(); 14 | } 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/collections/generics/GenericsCompileTimeErrorFix.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.collections.generics; 2 | 3 | import java.util.ArrayList; 4 | import java.util.List; 5 | 6 | public class GenericsCompileTimeErrorFix { 7 | 8 | public static void main(String[] args) { 9 | 10 | List integers = null; 11 | 12 | integers = new ArrayList(); 13 | 14 | integers.add(100); 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/escape/newline/AddNewLineExample5.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.escape.newline; 2 | 3 | public class AddNewLineExample5 { 4 | 5 | public static void main(String[] args) { 6 | 7 | // Using system dependent %n 8 | String line1 = "Hello engeers%nwelcome to the java blog"; 9 | 10 | System.out.println("print newline with %n line separator"); 11 | System.out.printf(line1); 12 | } 13 | } 14 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/getdatetime/SqlDateExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.getdatetime; 2 | 3 | import java.sql.Date; 4 | 5 | public class SqlDateExample { 6 | 7 | public static void main(String[] args) { 8 | 9 | long timeInMillis = System.currentTimeMillis(); 10 | 11 | Date sqlDate = new Date(timeInMillis); 12 | 13 | System.out.println("Current date from sql date : "+sqlDate); 14 | } 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/exit/JavaProgramExitExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.exit; 2 | 3 | public class JavaProgramExitExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | System.out.println("hello java developers "); 8 | System.out.println("understand how System.exit() method works"); 9 | 10 | System.exit(2); 11 | 12 | System.out.println("Last line from this program"); 13 | } 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/getdatetime/ClockExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.getdatetime; 2 | 3 | import java.time.Clock; 4 | import java.time.Instant; 5 | 6 | public class ClockExample { 7 | 8 | public static void main(String[] args) { 9 | Clock clockInUTC = Clock.systemUTC(); 10 | Instant instnat = clockInUTC.instant(); 11 | 12 | System.out.println("Java 8 - Current date time : "+instnat); 13 | } 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/booleanarray/BooleanArrayExample4.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.booleanarray; 2 | 3 | public class BooleanArrayExample4 { 4 | 5 | public static void main(String[] args) { 6 | 7 | boolean[] array4 = new boolean[4]; 8 | 9 | System.out.println("Checking the default values of boolean array 4 with for each loop"); 10 | for (boolean b : array4) { 11 | System.out.println(b); 12 | } 13 | 14 | } 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/initialize/ArrayDeclaration.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.initialize; 2 | 3 | public class ArrayDeclaration { 4 | 5 | public static void main(String[] args) { 6 | 7 | // int array declaration 8 | int[] intArray; 9 | 10 | // boolean array declaration 11 | boolean[] statusArray; 12 | 13 | // float array declaration 14 | float[] salaryArray; 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/nashorn/sample.js: -------------------------------------------------------------------------------- 1 | var BigDecimalClass = Java.type('java.math.BigDecimal'); 2 | 3 | function calculate(amount, percentage) { 4 | 5 | var result = new BigDecimalClass(amount).multiply(new BigDecimalClass(percentage)).divide( 6 | new BigDecimalClass("100"), 2, BigDecimalClass.ROUND_HALF_EVEN); 7 | 8 | return result.toPlainString(); 9 | } 10 | var result = calculate(1000,20); 11 | print("Final value : "+result); -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/keywords/finals/FInalVaraibleExamples4.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.keywords.finals; 2 | 3 | public class FInalVaraibleExamples4 { 4 | 5 | public static void main(String[] args) { 6 | 7 | final StringBuffer sb = new StringBuffer("hello"); 8 | 9 | sb.append(" world"); 10 | 11 | System.out.println("sb value - "+sb.toString()); 12 | 13 | //sb = new StringBuffer(); // compile time error 14 | } 15 | 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/StringsubSequenceWithNegativeExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings; 2 | 3 | public class StringsubSequenceWithNegativeExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | String stringObject = "This example is with negative index"; 8 | 9 | CharSequence output = stringObject.subSequence(-10, stringObject.length()); 10 | System.out.println(output); 11 | } 12 | } 13 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/split/StringSplitExample4.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings.split; 2 | 3 | public class StringSplitExample4 { 4 | 5 | public static void main(String[] args) { 6 | String phoneNo = "123-567-9080"; 7 | 8 | String[] spaceBasedSplitArray = phoneNo.split("-"); 9 | 10 | for(String value : spaceBasedSplitArray){ 11 | System.out.println(value); 12 | } 13 | } 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/getdatetime/LocalTimeExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.getdatetime; 2 | 3 | import java.time.LocalTime; 4 | 5 | public class LocalTimeExample { 6 | 7 | public static void main(String[] args) { 8 | 9 | // Using LocalTime class now() method 10 | LocalTime localTimeCurrentTime = LocalTime.now(); 11 | 12 | // using 13 | System.out.println("LocalTime : "+localTimeCurrentTime); 14 | } 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/timestamp/CurrentTimestampExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.timestamp; 2 | 3 | import java.time.Instant; 4 | import java.util.Date; 5 | 6 | public class CurrentTimestampExample2 { 7 | 8 | public static void main(String[] args) { 9 | 10 | Date dateNow = new Date(); 11 | 12 | Instant instant = dateNow.toInstant(); 13 | 14 | System.out.println("timestamp now : " + instant); 15 | } 16 | 17 | } 18 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/split/StringSplitExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings.split; 2 | 3 | public class StringSplitExample2 { 4 | 5 | public static void main(String[] args) { 6 | String str = "javaprogramto.comisfordevelopersandforfreshers"; 7 | 8 | String[] splitArray = str.split("for"); 9 | 10 | for(String value : splitArray){ 11 | System.out.println(value); 12 | } 13 | } 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/split/StringSplitExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings.split; 2 | 3 | public class StringSplitExample3 { 4 | 5 | public static void main(String[] args) { 6 | String str = "java programs for freshers"; 7 | 8 | String[] spaceBasedSplitArray = str.split(" "); 9 | 10 | for(String value : spaceBasedSplitArray){ 11 | System.out.println(value); 12 | } 13 | } 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/numbers/swap/SwapNumbersTemp.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.numbers.swap; 2 | 3 | public class SwapNumbersTemp { 4 | 5 | public static void main(String[] args) { 6 | 7 | int a = 10; 8 | int b = 20; 9 | 10 | System.out.println("Before swapping two numbers : a " + a + ", b " + b); 11 | int temp = a; 12 | a = b; 13 | b = temp; 14 | 15 | System.out.println("After swapping two numbers : a " + a + ", b " + b); 16 | } 17 | } 18 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/w3schools/programs/string/StringToLowercaseLocale.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.w3schools.programs.string; 2 | 3 | public class StringToLowercaseLocale { 4 | 5 | public static void main(String[] args) { 6 | 7 | String string = "HELLO WELCOME TO THE JAVAPROGRAMTO.COM"; 8 | String lowercaseStr = string.toLowerCase(); 9 | 10 | System.out.println("Lowercase converted string : "+lowercaseStr); 11 | } 12 | } 13 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/infinite/loops/DoWhileLoopInfiniteExample.java: -------------------------------------------------------------------------------- 1 | /** 2 | * Example to create infinite loop with do-while loop. 3 | * 4 | * @author javaprogramto.com 5 | * 6 | */ 7 | public class DoWhileLoopInfiniteExample { 8 | public static void main(String[] args) { 9 | 10 | // do-while loop condition to true. 11 | do { 12 | // core logic 13 | System.out.println("Running do-while loop"); 14 | } while(true); 15 | } 16 | } 17 | 18 | -------------------------------------------------------------------------------- /src/main/main.iml: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/collections/generics/GenericsCompileTimeError2Fix.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.collections.generics; 2 | 3 | import java.util.Map; 4 | import java.util.TreeMap; 5 | 6 | import com.javaprogramto.models.Employee; 7 | 8 | public class GenericsCompileTimeError2Fix { 9 | 10 | public static void main(String[] args) { 11 | 12 | Map integers = null; 13 | 14 | integers = new TreeMap(); 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/design/patterns/strategy1/algorithms/AdditionOperation.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.design.patterns.strategy1.algorithms; 2 | 3 | import com.javaprogramto.design.patterns.strategy1.strategy.IBaseOperation; 4 | 5 | public class AdditionOperation implements IBaseOperation { 6 | 7 | @Override 8 | public int doOperation(int value1, int value2) { 9 | int sum = value1 + value2; 10 | 11 | return sum; 12 | } 13 | 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/design/patterns/strategy1/algorithms/DivisionOperation.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.design.patterns.strategy1.algorithms; 2 | 3 | import com.javaprogramto.design.patterns.strategy1.strategy.IBaseOperation; 4 | 5 | public class DivisionOperation implements IBaseOperation { 6 | 7 | @Override 8 | public int doOperation(int value1, int value2) { 9 | int div = value1 / value2; 10 | 11 | return div; 12 | } 13 | 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java11/shebang/batch-job.sh: -------------------------------------------------------------------------------- 1 | #!/usr/local/bin/java --source 11 2 | 3 | import java.util.Arrays; 4 | import java.util.stream.IntStream; 5 | import java.util.stream.Stream; 6 | 7 | public class sum { 8 | public static void main(String[] args) { 9 | 10 | Stream stream = Arrays.stream(args); 11 | 12 | int sum = stream.mapToInt(Integer::parseInt).sum(); 13 | System.out.println("Total sum : "+sum); 14 | } 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/timestamp/CurrentTimestampExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.timestamp; 2 | 3 | import java.sql.Timestamp; 4 | 5 | public class CurrentTimestampExample1 { 6 | 7 | public static void main(String[] args) { 8 | 9 | long timestampInMillies = System.currentTimeMillis(); 10 | 11 | Timestamp timestamp = new Timestamp(timestampInMillies); 12 | System.out.println("timestamp now : "+timestamp); 13 | } 14 | 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/design/patterns/strategy1/algorithms/SubtractionOperation.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.design.patterns.strategy1.algorithms; 2 | 3 | import com.javaprogramto.design.patterns.strategy1.strategy.IBaseOperation; 4 | 5 | public class SubtractionOperation implements IBaseOperation { 6 | 7 | @Override 8 | public int doOperation(int value1, int value2) { 9 | int sub = value1 - value2; 10 | 11 | return sub; 12 | } 13 | 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/getdatetime/LocalDateTimeExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.getdatetime; 2 | 3 | import java.time.LocalDateTime; 4 | 5 | public class LocalDateTimeExample { 6 | 7 | public static void main(String[] args) { 8 | 9 | // using LocalDateTime class now() method 10 | LocalDateTime now = LocalDateTime.now(); 11 | 12 | // printing 13 | System.out.println("Current date time from LocalDateTime : "+now); 14 | } 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/escape/newline/AddNewLineExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.escape.newline; 2 | 3 | public class AddNewLineExample1 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String line1 = "Hello engeers"; 8 | String line2 = "hope you are staying safe"; 9 | 10 | String line3 = line1 + "\n" + line2; 11 | 12 | System.out.println("Mac or unix or linux newline with \\n"); 13 | System.out.println(line3); 14 | } 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/StringReplaceFirstExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings; 2 | 3 | public class StringReplaceFirstExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | String str = "Hello BOSS, Welcome to JavaProgramTo.com SUPER-BOSS"; 8 | 9 | String replacedString = str.replaceFirst("BOSS", "Boss"); 10 | 11 | System.out.println("Output of replaceFirst() method : " + replacedString); 12 | 13 | } 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/StringStartsWithCaseSensitiveExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings; 2 | 3 | public class StringStartsWithCaseSensitiveExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | System.out.println("Case senstive with upper case values : "+"HELLO WORLD".startsWith("hello")); 8 | 9 | System.out.println("how to handle case sensitives: "+"HELLO WORLD".toLowerCase().startsWith("hello")); 10 | 11 | } 12 | } 13 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/design/patterns/strategy1/algorithms/MultiplicationOperation.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.design.patterns.strategy1.algorithms; 2 | 3 | import com.javaprogramto.design.patterns.strategy1.strategy.IBaseOperation; 4 | 5 | public class MultiplicationOperation implements IBaseOperation { 6 | 7 | @Override 8 | public int doOperation(int value1, int value2) { 9 | int mul = value1 * value2; 10 | 11 | return mul; 12 | } 13 | 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/exception/IllegalArgumentException/IllegalArgumentExceptionExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.exception.IllegalArgumentException; 2 | 3 | import java.util.ArrayList; 4 | import java.util.List; 5 | 6 | public class IllegalArgumentExceptionExample { 7 | 8 | public static void main(String[] args) { 9 | 10 | // Example 1 11 | List list = new ArrayList<>(-10); 12 | list.add("a"); 13 | list.add("b"); 14 | list.add("c"); 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/getdatetime/LocalDateExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.getdatetime; 2 | 3 | import java.time.LocalDate; 4 | 5 | public class LocalDateExample { 6 | 7 | public static void main(String[] args) { 8 | 9 | // using LocalDate class 10 | LocalDate localDateCurrentDate = LocalDate.now(); 11 | 12 | // print the current date 13 | System.out.println("LocalDate current date : "+localDateCurrentDate); 14 | 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/todouble/StringToDoubleExample4.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.todouble; 2 | 3 | public class StringToDoubleExample4 { 4 | 5 | public static void main(String[] args) { 6 | 7 | // double value in string format 8 | String to_double = "1234abc"; 9 | 10 | Double doubleValue = Double.parseDouble(to_double); 11 | 12 | System.out.println("String to Double value with abc string : " + doubleValue); 13 | 14 | } 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/keywords/finals/Customer.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.keywords.finals; 2 | 3 | public class Customer { 4 | 5 | private int limit; 6 | //private final int newLimit; 7 | private static final int newLimit; 8 | 9 | /* public Customer(int limit, int newLimit) { 10 | 11 | this.limit = limit; 12 | this.newLimit = newLimit; 13 | } 14 | */ 15 | 16 | /*{ 17 | newLimit = 100; 18 | } 19 | */ 20 | static { 21 | newLimit = 200; 22 | } 23 | 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/count/CountNoCharStreamExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.count; 2 | 3 | public class CountNoCharStreamExample3 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String givenString = "hello world"; 8 | 9 | char givenChar = 'l'; 10 | 11 | long count = givenString.chars().filter(c -> c == givenChar).count(); 12 | 13 | System.out.println("no of occurrences of char 'l' is " + count); 14 | } 15 | 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/StringCodepointBeforeException.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings; 2 | 3 | public class StringCodepointBeforeException { 4 | 5 | public static void main(String[] args) { 6 | 7 | String str = "hello world"; 8 | 9 | System.out.println("Input string value : "+str); 10 | 11 | int codepointBefore = str.codePointBefore(-2); 12 | System.out.println("Code point for before index 0 : "+codepointBefore); 13 | } 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/split/StringSplitExample5.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings.split; 2 | 3 | public class StringSplitExample5 { 4 | 5 | public static void main(String[] args) { 6 | String delimitetAtEndString = "1235-567-9080-1234-----"; 7 | 8 | String[] spaceBasedSplitArray = delimitetAtEndString.split("-"); 9 | 10 | for(String value : spaceBasedSplitArray){ 11 | System.out.println(value); 12 | } 13 | } 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/exception/classcaseexception/ClassCastExceptionExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.exception.classcaseexception; 2 | 3 | public class ClassCastExceptionExample3 { 4 | 5 | public static void main(String[] args) { 6 | C c = new C(); 7 | 8 | if (c instanceof D) { 9 | D d = (D) c; 10 | } else { 11 | System.out.println("c is not instance of d. skipping.."); 12 | } 13 | } 14 | } 15 | 16 | class C { 17 | 18 | } 19 | 20 | class D extends C { 21 | 22 | } -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/optional/OptionalOrElseThrowExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.optional; 2 | 3 | public class OptionalOrElseThrowExample { 4 | public static void main(String[] args) { 5 | 6 | /* // orElseThrow() example 7 | String blank = Optional.ofNullable("").orElseThrow(); 8 | System.out.println(blank); 9 | 10 | String value = null; 11 | String blank2 = Optional.ofNullable(value).orElseThrow(); 12 | System.out.println(blank2); 13 | */ 14 | } 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/exit/JavaProgramExitExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.exit; 2 | 3 | public class JavaProgramExitExample3 { 4 | 5 | public static void main(String[] args) { 6 | 7 | System.out.println("first line from main method"); 8 | 9 | method(); 10 | 11 | System.out.println("last line from main method"); 12 | } 13 | 14 | private static void method() { 15 | 16 | System.out.println("executing the method"); 17 | return; 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/collections/generics/GenericsCompileTimeError2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.collections.generics; 2 | 3 | import java.util.Map; 4 | 5 | import com.javaprogramto.models.Employee; 6 | 7 | public class GenericsCompileTimeError2 { 8 | 9 | public static void main(String[] args) { 10 | 11 | Map integers = null; 12 | 13 | // uncomment the below line to see compile time error 14 | //integers = new TreeMap(); 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/collections/hashmap/print/HashMapPrintExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.collections.hashmap.print; 2 | 3 | import java.util.HashMap; 4 | import java.util.Map; 5 | 6 | public class HashMapPrintExample1 { 7 | 8 | public static void main(String[] args) { 9 | 10 | Map map = new HashMap<>(); 11 | 12 | map.put(1, "one"); 13 | map.put(2, "two"); 14 | map.put(3, "three"); 15 | 16 | System.out.println("map values : "+map); 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/intstream/toarray/IntStreamToArrayExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.intstream.toarray; 2 | 3 | import java.util.stream.IntStream; 4 | 5 | public class IntStreamToArrayExample { 6 | 7 | public static void main(String[] args) { 8 | 9 | IntStream oddNumbers = IntStream.iterate(1, i -> i +2); 10 | 11 | int[] oddArray = oddNumbers.limit(100).toArray(); 12 | 13 | System.out.println("Odd array length - "+oddArray.length); 14 | 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/streams/foreach/StreamFilterBreak.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.streams.foreach; 2 | 3 | import java.util.Arrays; 4 | import java.util.List; 5 | 6 | public class StreamFilterBreak { 7 | 8 | public static void main(String[] args) { 9 | 10 | List list = Arrays.asList("one", "two", "three", "seven", "nine", "ten"); 11 | 12 | list.stream().filter(s -> s.length() <= 3).forEach(value -> System.out.println(value)); 13 | } 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/escape/newline/AddNewLineExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.escape.newline; 2 | 3 | public class AddNewLineExample2 { 4 | 5 | public static void main(String[] args) { 6 | 7 | // windows os 8 | String line1 = "Hello engeers"; 9 | String line2 = "hope you are staying safe"; 10 | 11 | String line3 = line1 + "\r\n" + line2; 12 | 13 | System.out.println("windwos print newline with \\r\\n"); 14 | System.out.println(line3); 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/files/directory/CurrentDirectorySystemGetpropertyExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.files.directory; 2 | 3 | public class CurrentDirectorySystemGetpropertyExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | // Calling the getPropery() method with argument "user.dir" 8 | String currentDirectoryLocation = System.getProperty("user.dir"); 9 | 10 | System.out.println("Current working directoruy : " + currentDirectoryLocation); 11 | 12 | } 13 | 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/integer/IntegerHashcodeExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.integer; 2 | 3 | public class IntegerHashcodeExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | Integer unsignedInteger1 = Integer.hashCode(100); 8 | System.out.println("hashcode integer for 100 is " + unsignedInteger1); 9 | 10 | Integer unsignedInteger2 = Integer.hashCode(200); 11 | System.out.println("hashcode integer for 4294967196 is " + unsignedInteger2); 12 | } 13 | } 14 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/keywords/finals/FInalVaraibleExamples3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.keywords.finals; 2 | 3 | public class FInalVaraibleExamples3 { 4 | 5 | final int limit = 3; 6 | 7 | public static void main(String[] args) { 8 | 9 | FInalVaraibleExamples3 fInalVaraibleExamples3 = new FInalVaraibleExamples3(); 10 | System.out.println("limit " + fInalVaraibleExamples3.getLimit()); 11 | 12 | } 13 | 14 | public int getLimit() { 15 | 16 | return this.limit; 17 | } 18 | 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/collections/set/add/TreeSetAddExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.collections.set.add; 2 | 3 | import java.util.Set; 4 | import java.util.TreeSet; 5 | 6 | public class TreeSetAddExample { 7 | 8 | public static void main(String[] args) { 9 | 10 | Set set = new TreeSet<>(); 11 | 12 | set.add(20); 13 | set.add(10); 14 | set.add(90); 15 | set.add(50); 16 | set.add(300); 17 | 18 | System.out.println("TreeSet values are sorted : " + set); 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/escape/newline/AddNewLineExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.escape.newline; 2 | 3 | public class AddNewLineExample3 { 4 | 5 | public static void main(String[] args) { 6 | 7 | // old mac os based 8 | String line1 = "Hello engeers"; 9 | String line2 = "hope you are staying safe"; 10 | 11 | String line3 = line1 + "\r" + line2; 12 | 13 | System.out.println("Old mac os print newline with \\r"); 14 | System.out.println(line3); 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/StringReplaceFirstPatternSyntaxException.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings; 2 | 3 | public class StringReplaceFirstPatternSyntaxException { 4 | 5 | public static void main(String[] args) { 6 | 7 | String str = "Pattern invalid program"; 8 | 9 | String replacedString = str.replaceFirst("[invalid}}", "invalid is not accecpted"); 10 | 11 | System.out.println("replaceFirst() special chars output : " + replacedString); 12 | 13 | } 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/getdatetime/ZonedDateTimeExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.getdatetime; 2 | 3 | import java.time.ZonedDateTime; 4 | 5 | public class ZonedDateTimeExample { 6 | 7 | public static void main(String[] args) { 8 | 9 | // Using ZonedDateTime class now() method 10 | ZonedDateTime zonedDateTime = ZonedDateTime.now(); 11 | 12 | // print current date time from ZonedDateTime class. 13 | System.out.println("ZonedDateTime : "+zonedDateTime); 14 | } 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/remove/character/StringRemoveCharacterExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.remove.character; 2 | 3 | public class StringRemoveCharacterExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | String input = "hello world 00"; 8 | 9 | String output = input.replaceAll("0", ""); 10 | 11 | System.out.println("Input string 1 : "+input); 12 | System.out.println("Output string after removing the + symbol : "+output); 13 | } 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/StringReplaceFirstSpecialCharsExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings; 2 | 3 | public class StringReplaceFirstSpecialCharsExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | String str = "How many $$ you have ? Do you have valid $$ amount?"; 8 | 9 | String replacedString = str.replaceFirst("\\$\\$", "Dollars"); 10 | 11 | System.out.println("replaceFirst() special chars output : " + replacedString); 12 | 13 | } 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/characters/PrintLowerCaseAlphabets.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.characters; 2 | 3 | public class PrintLowerCaseAlphabets { 4 | 5 | public static void main(String[] args) { 6 | 7 | // first character 8 | char firstChar = 'a'; 9 | 10 | // last character 11 | char lastChar = 'z'; 12 | 13 | // print lowercase letters from a to z 14 | for (char c = firstChar; c <= lastChar; c++) { 15 | System.out.print(c + " "); 16 | 17 | } 18 | 19 | } 20 | 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/characters/PrintUpperCaseAlphabets.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.characters; 2 | 3 | public class PrintUpperCaseAlphabets { 4 | 5 | public static void main(String[] args) { 6 | 7 | // first character 8 | char firstChar = 'A'; 9 | 10 | // last character 11 | char lastChar = 'Z'; 12 | 13 | // print uppercase letters from A to Z 14 | for (char c = firstChar; c <= lastChar; c++) { 15 | System.out.print(c + " "); 16 | 17 | } 18 | 19 | } 20 | 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/maths/MultiplyFloatingNumbers.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.maths; 2 | 3 | public class MultiplyFloatingNumbers { 4 | 5 | public static void main(String[] args) { 6 | 7 | // first floating number 8 | float f1 = 2.5f; 9 | 10 | // second floating number 11 | float f2 = 4.0f; 12 | 13 | // result of multiplication of two numbers. 14 | float result = f1 * f2; 15 | 16 | // printing 17 | System.out.println("Result is : " + result); 18 | 19 | } 20 | 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/mix/StringsConcatenateExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings.mix; 2 | 3 | public class StringsConcatenateExample1 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String s1 = new String("JavaProgramTo.com"); 8 | String s2 = "welcome, Java developer"; 9 | 10 | String s3 = s1 + s2; 11 | System.out.println("Mixed string 1 : "+s3); 12 | 13 | String s4 = "this is a " + "new string"; 14 | System.out.println("Mixed string 2 : "+s4); 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/print/PrintMultiDimenstionalArray.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.print; 2 | 3 | import java.util.Arrays; 4 | 5 | public class PrintMultiDimenstionalArray { 6 | 7 | public static void main(String[] args) { 8 | int[][] twoArray = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9, 0 } }; 9 | 10 | System.out.println("Using Arrays.toString : " + Arrays.toString(twoArray)); 11 | 12 | System.out.println("Using Arrays.toString : " + Arrays.deepToString(twoArray)); 13 | 14 | } 15 | 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/foreach/Java8ForEachListAddExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.foreach; 2 | 3 | import java.util.ArrayList; 4 | import java.util.List; 5 | 6 | public class Java8ForEachListAddExample { 7 | 8 | public static void main(String[] args) { 9 | 10 | List list = new ArrayList<>(); 11 | list.add("One"); 12 | 13 | list.forEach((s) -> list.add(s + 1)); 14 | 15 | System.out.println("Final list : " + list); 16 | 17 | } 18 | 19 | } 20 | 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/keywords/extend/InterfaceExtendsExamples.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.keywords.extend; 2 | 3 | public class InterfaceExtendsExamples { 4 | 5 | public static void main(String[] args) { 6 | 7 | 8 | } 9 | } 10 | 11 | 12 | interface Payment { 13 | 14 | boolean processPayment(); 15 | 16 | } 17 | 18 | interface CreditCardPayment extends Payment{ 19 | 20 | void validateCardDetails(); 21 | } 22 | 23 | interface UPIPayment extends Payment{ 24 | 25 | void validateUPIAddress(); 26 | } 27 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/count/CountDigitsMathLog10Example.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.count; 2 | 3 | public class CountDigitsMathLog10Example { 4 | 5 | public static void main(String[] args) { 6 | 7 | // Input number 8 | int number = 123; 9 | 10 | String numberInString = Integer.toString(number); 11 | 12 | int length = numberInString.length(); 13 | 14 | // printing the output 15 | System.out.println("No of digits in number " + number + " is " + length); 16 | 17 | 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/escape/EscapeSlashTExample4.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.escape; 2 | 3 | public class EscapeSlashTExample4 { 4 | 5 | public static void main(String[] args) { 6 | 7 | System.out.println("hello world \t welcome"); 8 | 9 | System.out.println("how\tare\tyou\tdoing\t?"); 10 | 11 | String str1 = "One"; 12 | String str2 = "Two"; 13 | String str3 = "Three"; 14 | 15 | String str = str1 + "\t" + str2 + "\t" + str3; 16 | 17 | System.out.println(str); 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/w3schools/programs/ascii/StringToAscii.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.w3schools.programs.ascii; 2 | 3 | 4 | public class StringToAscii { 5 | 6 | public static void main(String[] args) { 7 | String str = "hello javaprogramto.com"; 8 | 9 | char[] array = str.toCharArray(); 10 | 11 | System.out.println("ASCII codes for string "+str+" are : "); 12 | for (char c : array) { 13 | 14 | System.out.println((int)c); 15 | 16 | } 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/getdatetime/CalendarExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.getdatetime; 2 | 3 | import java.util.Calendar; 4 | import java.util.Date; 5 | 6 | public class CalendarExample { 7 | 8 | public static void main(String[] args) { 9 | 10 | // Getting the calendar object 11 | Calendar cal = Calendar.getInstance(); 12 | 13 | // Getting the util Date. 14 | Date currentDateTime = cal.getTime(); 15 | System.out.println("Current Date Time : "+currentDateTime); 16 | } 17 | } 18 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/count/CountDigitsIntegerToStringExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.count; 2 | 3 | public class CountDigitsIntegerToStringExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | // Input number 8 | int number = 123; 9 | 10 | String numberInString = Integer.toString(number); 11 | 12 | int length = numberInString.length(); 13 | 14 | // printing the output 15 | System.out.println("No of digits in number " + number + " is " + length); 16 | 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/booleanarray/BooleanArrayExample6.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.booleanarray; 2 | 3 | import java.util.Arrays; 4 | 5 | public class BooleanArrayExample6 { 6 | 7 | public static void main(String[] args) { 8 | 9 | boolean[] array6 = new boolean[5]; 10 | 11 | System.out.println("Default values of array5 are " + Arrays.toString(array6)); 12 | 13 | Arrays.fill(array6, true); 14 | 15 | System.out.println("New Default values of array5 are " + Arrays.toString(array6)); 16 | } 17 | } 18 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/initialize/ArrayInitializationDefaultValues.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.initialize; 2 | 3 | public class ArrayInitializationDefaultValues { 4 | 5 | public static void main(String[] args) { 6 | 7 | // int array initialization 8 | int[] intArray = new int[9]; 9 | 10 | System.out.println("Printing array values : "); 11 | for(int i = 0; i < intArray.length ; i++){ 12 | System.out.println(intArray[i]); 13 | } 14 | 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/arraylist/ArrayListMaxSizeExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.arraylist; 2 | 3 | import java.util.ArrayList; 4 | import java.util.List; 5 | 6 | public class ArrayListMaxSizeExample { 7 | 8 | public static void main(String[] args) { 9 | 10 | // default size is 10 11 | List intList = new ArrayList<>(); 12 | for (int i = 0; i < 10; i++) { 13 | intList.add(i); 14 | } 15 | 16 | System.out.println("Int list size (default) - " + intList.size()); 17 | 18 | } 19 | 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/iterate/IterateForEachExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.iterate; 2 | 3 | import java.util.Arrays; 4 | import java.util.Iterator; 5 | import java.util.List; 6 | 7 | public class IterateForEachExample { 8 | 9 | public static void main(String[] args) { 10 | 11 | List strings = Arrays.asList("A", "B", "C", "D"); 12 | 13 | Iterator it = strings.iterator(); 14 | 15 | while(it.hasNext()) { 16 | System.out.println(it.next()); 17 | } 18 | 19 | } 20 | 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/infinite/loops/ForLoopInfiniteExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.infinite.loops; 2 | 3 | /** 4 | * Example to create infinite loop with for loop. 5 | * 6 | * @author javaprogramto.com 7 | * 8 | */ 9 | public class ForLoopInfiniteExample { 10 | 11 | public static void main(String[] args) { 12 | 13 | // for loop condition to true. 14 | // this loop runs forever. 15 | for (; true;) { 16 | // core logic 17 | System.out.println("Running loop"); 18 | } 19 | } 20 | 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/count/CountNoCharStreamExample4.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.count; 2 | 3 | public class CountNoCharStreamExample4 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String givenString = "hello world"; 8 | 9 | char givenChar = 'l'; 10 | 11 | long count = givenString.chars() 12 | .filter(c -> c == givenChar) 13 | .reduce(0, (a, b) -> a + 1); 14 | 15 | System.out.println("no of occurrences of char 'l' is " + count); 16 | } 17 | 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/setall/IntArraySetAllExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.setall; 2 | 3 | import java.util.Arrays; 4 | 5 | public class IntArraySetAllExample { 6 | 7 | public static void main(String[] args) { 8 | 9 | int[] intArray = new int[7]; 10 | 11 | System.out.println("original array : "+ Arrays.toString(intArray)); 12 | 13 | Arrays.setAll(intArray, i -> (i + 1) * 2); 14 | 15 | System.out.println("array.setAll() output: "+ Arrays.toString(intArray)); 16 | } 17 | } 18 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/comparator/reverse/ComparatorReverse.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.comparator.reverse; 2 | 3 | import java.util.Arrays; 4 | import java.util.Collections; 5 | import java.util.List; 6 | 7 | public class ComparatorReverse { 8 | 9 | public static void main(String[] args) { 10 | 11 | List list = Arrays.asList("1", "3", "2"); 12 | 13 | System.out.println("Original list - " + list); 14 | Collections.reverse(list); 15 | System.out.println("Reversed list - " + list); 16 | 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/timestamp/CurrentTimestampExample4.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.timestamp; 2 | 3 | import java.sql.Timestamp; 4 | import java.time.Instant; 5 | 6 | public class CurrentTimestampExample4 { 7 | 8 | public static void main(String[] args) { 9 | 10 | long timeInMillis = System.currentTimeMillis(); 11 | 12 | Timestamp timestamp = new Timestamp(timeInMillis); 13 | 14 | Instant instant = timestamp.toInstant(); 15 | 16 | System.out.println("timestamp now : " + instant); 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/instant/InstantCreationExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.instant; 2 | 3 | import java.time.Instant; 4 | 5 | public class InstantCreationExample { 6 | 7 | public static void main(String[] args) { 8 | 9 | // Creating instant object from now() 10 | Instant instant1 = Instant.now(); 11 | System.out.println("Instant 1 value from now() - " + instant1); 12 | 13 | Instant instant2 = Instant.now(); 14 | System.out.println("Instant 2 value from now() - " + instant2); 15 | } 16 | 17 | } 18 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/infinite/loops/WhileLoopInfiniteExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.infinite.loops; 2 | 3 | /** 4 | * Example to create infinite loop with while loop. 5 | * 6 | * @author javaprogramto.com 7 | * 8 | */ 9 | public class WhileLoopInfiniteExample { 10 | 11 | public static void main(String[] args) { 12 | 13 | // while loop condition to true. 14 | // this loop runs forever. 15 | while (true) { 16 | // core logic 17 | System.out.println("Running while loop"); 18 | } 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/StringsubSequenceExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings; 2 | 3 | public class StringsubSequenceExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | String stringObject = "javaprogramto.com is a java blog"; 8 | 9 | CharSequence output1 = stringObject.subSequence(20, stringObject.length()); 10 | System.out.println(output1); 11 | 12 | CharSequence output2 = stringObject.subSequence(0, 18); 13 | System.out.println(output2); 14 | 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/exception/IllegalArgumentException/IllegalArgumentExceptionExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.exception.IllegalArgumentException; 2 | 3 | import java.util.ArrayList; 4 | import java.util.List; 5 | 6 | public class IllegalArgumentExceptionExample2 { 7 | 8 | public static void main(String[] args) { 9 | 10 | // Example 2 11 | List stringsList = new ArrayList<>(); 12 | stringsList.add("a"); 13 | stringsList.add("b"); 14 | stringsList.add("c"); 15 | 16 | stringsList.stream().skip(-100); 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/foreach/NormalForEachExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.foreach; 2 | 3 | 4 | import java.util.ArrayList; 5 | import java.util.List; 6 | 7 | public class NormalForEachExample { 8 | 9 | public static void main(String[] args) { 10 | 11 | List list = new ArrayList<>(); 12 | 13 | for (int i = 0; i < 10; i++) { 14 | 15 | list.add("Item " + i + 1); 16 | } 17 | 18 | System.out.println("Normal for loop program : " + list); 19 | 20 | } 21 | 22 | } 23 | 24 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/optional/OptionalIsPresent.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.optional; 2 | 3 | import java.util.Optional; 4 | 5 | public class OptionalIsPresent { 6 | public static void main(String[] args) { 7 | 8 | // Creating optional 9 | Optional ofNullable = Optional.ofNullable("Non null value"); 10 | 11 | String content = ofNullable.get(); 12 | System.out.println("Offnullable value :" + content); 13 | 14 | // passing null value 15 | Optional nullOptional = Optional.ofNullable(null); 16 | 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/large/Largest3NumbersOptimizedExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.large; 2 | 3 | public class Largest3NumbersOptimizedExample2 { 4 | 5 | public static void main(String[] args) { 6 | 7 | int number1 = -1000; 8 | int number2 = -2000; 9 | int number3 = -300; 10 | 11 | int max = number2; 12 | 13 | if (number1 >= number2) { 14 | max = number1; 15 | } 16 | 17 | if (number3 >= max) { 18 | max = number3; 19 | } 20 | 21 | System.out.println(max + " is biggest number"); 22 | } 23 | 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/mix/StringsConcatenateExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings.mix; 2 | 3 | public class StringsConcatenateExample2 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String s1 = new String("JavaProgramTo.com"); 8 | String s2 = "welcome, Java developer"; 9 | 10 | String s3 = s1.concat(s2); 11 | System.out.println("Mixed string 1 using concat() :: " + s3); 12 | 13 | String s4 = "this is a ".concat("new string"); 14 | System.out.println("Mixed string 2 using concat() : : " + s4); 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/files/printwriter/newline/PrintWriterNewLine2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.files.printwriter.newline; 2 | 3 | import java.io.PrintWriter; 4 | 5 | public class PrintWriterNewLine2 { 6 | 7 | public static void main(String[] args) { 8 | 9 | PrintWriter printWriter = new PrintWriter(System.out); 10 | 11 | printWriter.println("this is the first line"); 12 | printWriter.println("this is the second line"); 13 | printWriter.println("third line"); 14 | 15 | printWriter.flush(); 16 | 17 | printWriter.close(); 18 | 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/collectors/tolist/StreamCollectToListExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.collectors.tolist; 2 | 3 | import java.util.List; 4 | import java.util.stream.Collectors; 5 | import java.util.stream.Stream; 6 | 7 | public class StreamCollectToListExample1 { 8 | 9 | public static void main(String[] args) { 10 | Stream vowels = Stream.of("A", "E", "I", "O", "U"); 11 | 12 | List list = vowels.collect(Collectors.toList()); 13 | 14 | System.out.println("stream collect to list output : " + list); 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/split/StringSplitExample6.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings.split; 2 | 3 | public class StringSplitExample6 { 4 | 5 | public static void main(String[] args) { 6 | String delimitetAtEndString = "1235--------89"; 7 | 8 | String[] spaceBasedSplitArray = delimitetAtEndString.split("-"); 9 | 10 | System.out.println("returned array size : "+spaceBasedSplitArray.length); 11 | for(String value : spaceBasedSplitArray){ 12 | System.out.println(value); 13 | } 14 | } 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/returns/ArrayReturnExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.returns; 2 | 3 | import java.util.Arrays; 4 | 5 | public class ArrayReturnExample1 { 6 | 7 | public static void main(String[] args) { 8 | 9 | int[] first5Numbers = getNumbers(); 10 | 11 | System.out.println("Array returned from method : " + Arrays.toString(first5Numbers)); 12 | 13 | } 14 | 15 | // returning an array from method 16 | public static int[] getNumbers() { 17 | 18 | int[] numbers = { 1, 2, 3, 4, 5 }; 19 | 20 | return numbers; 21 | } 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/toiterabale/ArrayIterate.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.toiterabale; 2 | 3 | /** 4 | * 5 | * Array Iterate example using loops 6 | * 7 | * @author javaprogramto.com 8 | * 9 | */ 10 | public class ArrayIterate { 11 | 12 | public static void main(String[] args) { 13 | 14 | // string array 15 | String[] names = new String[] {"john", "Amal", "Paul"}; 16 | 17 | // iterating array over its values. 18 | for(int index=0; index< names.length ; index++) { 19 | System.out.println(names[index]); 20 | } 21 | } 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/remove/character/StringRemoveCharacterExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.remove.character; 2 | 3 | import java.util.regex.Pattern; 4 | 5 | public class StringRemoveCharacterExample2 { 6 | 7 | public static void main(String[] args) { 8 | 9 | String input = "hello +world ++"; 10 | 11 | String output = input.replaceAll(Pattern.quote("+"), ""); 12 | 13 | System.out.println("Input string 1 : "+input); 14 | System.out.println("Output string after removing the + symbol : "+output); 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/timestamp/CurrentTimestampExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.timestamp; 2 | 3 | import java.text.SimpleDateFormat; 4 | import java.util.Date; 5 | 6 | public class CurrentTimestampExample3 { 7 | 8 | public static void main(String[] args) { 9 | 10 | SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); 11 | Date dateNow = new Date(); 12 | 13 | String timestampNow = simpleDateFormat.format(dateNow); 14 | 15 | System.out.println("timestamp now : " + timestampNow); 16 | } 17 | 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/optional/OptionalFilterExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.optional; 2 | 3 | import java.util.Optional; 4 | 5 | public class OptionalFilterExample { 6 | public static void main(String[] args) { 7 | 8 | // Creating optional 9 | Optional op = Optional.ofNullable(1234); 10 | 11 | Optional evenOrNot = op.filter(number -> number % 2 == 0); 12 | /* 13 | if (evenOrNot.isEmpty()) { 14 | System.out.println("Odd number"); 15 | } else { 16 | System.out.println("Even number"); 17 | } 18 | */ 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/streams/reduce/StreamReduceExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.streams.reduce; 2 | 3 | import java.util.Arrays; 4 | import java.util.List; 5 | 6 | public class StreamReduceExample2 { 7 | 8 | public static void main(String[] args) { 9 | 10 | Integer sumOf1to7 = 28; 11 | 12 | List numbers = Arrays.asList(8, 9, 10); 13 | 14 | Integer sum = numbers.stream().reduce(sumOf1to7, (currentSum, nextValue) -> currentSum + nextValue); 15 | 16 | System.out.println("sum of first 10 numbers is " + sum); 17 | } 18 | 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/keywords/finals/FInalVaraibleExamples.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.keywords.finals; 2 | 3 | public class FInalVaraibleExamples { 4 | 5 | public static void main(String[] args) { 6 | 7 | // normal local variable 8 | int i = 10; 9 | i = 20; 10 | System.out.println("local i = " + i); 11 | 12 | // final local variable with value reassignment 13 | final int j = 10; 14 | 15 | // uncomment the below line to see compile time error 16 | //j = 20; // compile time error 17 | System.out.println("final j = " + j); 18 | } 19 | 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/escape/newline/AddNewLineExample6.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.escape.newline; 2 | 3 | public class AddNewLineExample6 { 4 | 5 | public static void main(String[] args) { 6 | 7 | // html break tag 8 | String tag1 = "

hello

"; 9 | String tag2 = "

world

"; 10 | 11 | String tag3 = tag1 + "
" + tag2; 12 | 13 | // using java \n 14 | String tag4 = tag1 + "\n" + tag3; 15 | 16 | // using unicodes 17 | 18 | String tag5 = "

This is paragraph text and woops there is a new line.

"; 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/escape/newline/AddNewLineExample4.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.escape.newline; 2 | 3 | public class AddNewLineExample4 { 4 | 5 | public static void main(String[] args) { 6 | 7 | // Using java api system class getProperty() method 8 | String line1 = "Hello engeers"; 9 | String line2 = "hope you are staying safe"; 10 | 11 | String line3 = line1 + System.getProperty("line.separator") + line2; 12 | 13 | System.out.println("print newline with System.getPropertyr() method"); 14 | System.out.println(line3); 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/w3schools/programs/ascii/StringToAsciiByteCasting.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.w3schools.programs.ascii; 2 | 3 | public class StringToAsciiByteCasting { 4 | 5 | public static void main(String[] args) { 6 | 7 | String input = "byte casting"; 8 | 9 | char[] array = input.toCharArray(); 10 | 11 | StringBuffer sb = new StringBuffer(); 12 | for (char ch: array) { 13 | sb.append((byte)ch).append(" "); 14 | 15 | } 16 | 17 | System.out.println("byte casting output : "+sb); 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/collections/hashmap/print/HashMapPrintExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.collections.hashmap.print; 2 | 3 | import java.util.HashMap; 4 | import java.util.Map; 5 | import java.util.Set; 6 | 7 | public class HashMapPrintExample3 { 8 | 9 | public static void main(String[] args) { 10 | 11 | Map map = new HashMap<>(); 12 | 13 | map.put(1, "one"); 14 | map.put(2, "two"); 15 | map.put(3, "three"); 16 | 17 | Set> set = map.entrySet(); 18 | 19 | set.forEach(System.out::println); 20 | 21 | } 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/split/StringSplitExample7.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings.split; 2 | 3 | public class StringSplitExample7 { 4 | 5 | public static void main(String[] args) { 6 | String multipleDelimiters = "hello,welcome to;java$program#to.com"; 7 | 8 | String[] spaceBasedSplitArray = multipleDelimiters.split("[, ;$#]"); 9 | 10 | System.out.println("returned array size : "+spaceBasedSplitArray.length); 11 | for(String value : spaceBasedSplitArray){ 12 | System.out.println(value); 13 | } 14 | } 15 | } 16 | -------------------------------------------------------------------------------- /.idea/$PRODUCT_WORKSPACE_FILE$: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | 7 | 1.8.0_252 8 | 9 | 14 | 15 | 16 | 17 | 18 | 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/localdate/LocalDateCreation.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.localdate; 2 | 3 | import java.time.LocalDate; 4 | 5 | public class LocalDateCreation { 6 | 7 | public static void main(String[] args) { 8 | 9 | // Dates creation with now() and of() methods. 10 | LocalDate currentDate = LocalDate.now(); 11 | LocalDate futureDate = LocalDate.of(2025, 10, 10); 12 | 13 | // printing the dates. 14 | System.out.println("Current date : " + currentDate); 15 | System.out.println("Future date : " + futureDate); 16 | 17 | } 18 | 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/StringHashcodeExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings; 2 | 3 | public class StringHashcodeExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | String str = "hello string fan"; 8 | 9 | int hashValue = str.hashCode(); 10 | 11 | System.out.println("hash code of string : "+hashValue); 12 | 13 | String newString = "this is a new string"; 14 | 15 | int newStrHashValue = newString.hashCode(); 16 | 17 | System.out.println("New string hash value : "+newStrHashValue); 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/design/patterns/strategy1/context/OperationContext.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.design.patterns.strategy1.context; 2 | 3 | import com.javaprogramto.design.patterns.strategy1.strategy.IBaseOperation; 4 | 5 | public class OperationContext { 6 | 7 | private IBaseOperation iBaseOperation; 8 | 9 | public OperationContext(IBaseOperation iBaseOperation) { 10 | this.iBaseOperation = iBaseOperation; 11 | } 12 | 13 | public int executeStrategy(int value1, int value2) { 14 | return iBaseOperation.doOperation(value1, value2); 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/exception/IllegalArgumentException/IllegalArgumentExceptionExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.exception.IllegalArgumentException; 2 | 3 | import com.javaprogramto.java8.compare.Employee; 4 | 5 | public class IllegalArgumentExceptionExample3 { 6 | 7 | public static void main(String[] args) { 8 | 9 | // Example 3 10 | Employee employeeRequest = new Employee(222, "Ram", 17); 11 | 12 | if (employeeRequest.getAge() < 18 || employeeRequest.getAge() > 65) { 13 | throw new IllegalArgumentException("Invalid age for the emp req"); 14 | } 15 | 16 | } 17 | } 18 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/files/printwriter/PrintWriterExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.files.printwriter; 2 | 3 | import java.io.PrintWriter; 4 | 5 | public class PrintWriterExample1 { 6 | 7 | public static void main(String[] args) { 8 | 9 | PrintWriter writer = new PrintWriter(System.out); 10 | writer.write("First line of console "); 11 | writer.write("Second line of console"); 12 | 13 | writer.flush(); 14 | 15 | boolean hasError = writer.checkError(); 16 | System.out.println(" any error in processing - "+hasError); 17 | 18 | writer.close(); 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/empty/ReturnEmptyArrayExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.empty; 2 | 3 | public class ReturnEmptyArrayExample1 { 4 | 5 | public static void main(String[] args) { 6 | 7 | if (true) { 8 | int[] array1 = emptyArray(); 9 | System.out.println("Length of int array 1 : " + array1.length); 10 | } 11 | 12 | if( 40 % 10 == 0) { 13 | int[] array2 = emptyArray(); 14 | System.out.println("Length of int array 2 : " + array2.length); 15 | } 16 | 17 | } 18 | 19 | public static int[] emptyArray() { 20 | 21 | return new int[0]; 22 | } 23 | } 24 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/datatypes/diff/FloatVsDoubleDataLoss.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.datatypes.diff; 2 | 3 | public class FloatVsDoubleDataLoss { 4 | 5 | public static void main(String[] args) { 6 | 7 | // double examples 8 | double d = 1.2345678912345678; 9 | 10 | float f = (float) d; 11 | 12 | System.out.println("float value after double to float conversion (data loss) - " + f); 13 | 14 | // float examples 15 | float f1 = 1.1111111f; 16 | 17 | double d1 = f1; 18 | 19 | System.out.println("\n" + "double value after float to double conversion - " + d1); 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/exception/classcaseexception/ClassCastExceptionExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.exception.classcaseexception; 2 | 3 | import java.util.ArrayList; 4 | import java.util.List; 5 | 6 | public class ClassCastExceptionExample2 { 7 | 8 | public static void main(String[] args) { 9 | 10 | List list = new ArrayList<>(); 11 | 12 | list.add(10); 13 | list.add(20); 14 | list.add("String"); 15 | list.add(30); 16 | 17 | for (int i = 0; i < list.size(); i++) { 18 | Integer value = (Integer) list.get(i); 19 | System.out.println(value); 20 | } 21 | } 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/anymatch/AnyMatchOnEmptyStream.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.anymatch; 2 | 3 | import java.util.stream.Stream; 4 | 5 | public class AnyMatchOnEmptyStream { 6 | 7 | public static void main(String[] args) { 8 | 9 | Stream emptyStream = Stream.empty(); 10 | 11 | boolean found = emptyStream.anyMatch(str -> str.length() > 0); 12 | 13 | if(found){ 14 | System.out.println("Stream has values"); 15 | } else { 16 | System.out.println("Stream is empty and no values"); 17 | } 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/chars/AddCharToStringExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.chars; 2 | 3 | public class AddCharToStringExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | // adding the char at the end of string 8 | String addingChar = "hello" + 'A'; 9 | 10 | // adding multiple chars at the end of the string 11 | String addingChars = "hello" + 'A' + ',' + 'B'; 12 | 13 | System.out.println("adding single char to the string at the end - "+addingChar); 14 | System.out.println("adding miltiple chars to the string at the end - "+addingChars); 15 | 16 | } 17 | } 18 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/streams/foreach/StreamTakeWhile.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.streams.foreach; 2 | 3 | import java.util.Arrays; 4 | import java.util.List; 5 | 6 | public class StreamTakeWhile { 7 | 8 | public static void main(String[] args) { 9 | 10 | List list = Arrays.asList("one", "two", "three", "seven", "nine"); 11 | 12 | // list.stream().takeWhile(value -> value.length() > 3).forEach(value -> { 13 | // if (value.length() > 3) { 14 | // System.out.println(value); 15 | // } 16 | // }); 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/count/CountNoCharExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.count; 2 | 3 | public class CountNoCharExample1 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String givenString = "hello world"; 8 | 9 | char givenChar = 'l'; 10 | 11 | int strLength = givenString.length(); 12 | int count = 0; 13 | 14 | for (int i = 0; i < strLength; i++) { 15 | 16 | if(givenChar == givenString.charAt(i)) { 17 | count++; 18 | } 19 | } 20 | 21 | System.out.println("no of occurrences of char 'l' is "+count); 22 | } 23 | 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/streams/optionals/returntype/Employee.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.streams.optionals.returntype; 2 | 3 | import java.io.Serializable; 4 | import java.util.Optional; 5 | 6 | public class Employee implements Serializable { 7 | 8 | private int id; 9 | 10 | private Optional salary; 11 | 12 | // setters and getters 13 | 14 | private String name; 15 | 16 | public Optional getName() { 17 | return Optional.ofNullable(name); 18 | } 19 | 20 | public void setName(String name) { 21 | this.name = name; 22 | } 23 | 24 | 25 | 26 | 27 | } 28 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/scanner/close/ScannerCloseExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.scanner.close; 2 | 3 | import java.util.Scanner; 4 | 5 | public class ScannerCloseExample1 { 6 | 7 | public static void main(String[] args) { 8 | Scanner scanner = new Scanner(System.in); 9 | 10 | System.out.println("Enter your birth year"); 11 | int year = scanner.nextInt(); 12 | 13 | System.out.println("Enter your age "); 14 | int age = scanner.nextInt(); 15 | 16 | scanner.close(); 17 | 18 | System.out.println("Given age and year are (" + age + "," + year + ")"); 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/remove/character/StringRemoveCharacterExample5.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.remove.character; 2 | 3 | import org.apache.commons.lang3.StringUtils; 4 | 5 | public class StringRemoveCharacterExample5 { 6 | 7 | public static void main(String[] args) { 8 | 9 | String input = "hello +world ++"; 10 | char removalCh = '+'; 11 | 12 | String output = StringUtils.remove(input, removalCh); 13 | 14 | System.out.println("Input string 1 : " + input); 15 | System.out.println("Output string after removing the + symbol : " + output); 16 | } 17 | } 18 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/multidimensional/NestedArraysExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.multidimensional; 2 | 3 | import org.apache.commons.lang3.ArrayUtils; 4 | 5 | public class NestedArraysExample1 { 6 | 7 | public static void main(String[] args) { 8 | 9 | int[] array1 = {}; 10 | 11 | int[] array2 = new int[0]; 12 | 13 | int[] array3 = ArrayUtils.EMPTY_INT_ARRAY; 14 | 15 | System.out.println("array1 length is "+array1.length); 16 | System.out.println("array2 length is "+array2.length); 17 | System.out.println("array3 length is "+array3.length); 18 | 19 | } 20 | 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/timestamp/CurrentTimestampExample7.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.timestamp; 2 | 3 | import java.time.LocalDateTime; 4 | import java.time.format.DateTimeFormatter; 5 | 6 | public class CurrentTimestampExample7 { 7 | 8 | public static void main(String[] args) { 9 | 10 | LocalDateTime localDateTime = LocalDateTime.now(); 11 | 12 | DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss SSS"); 13 | 14 | String timestamp = formatter.format(localDateTime); 15 | 16 | System.out.println("timestamp now : " + timestamp); 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/optional/OptionalIfPresentExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.optional; 2 | 3 | import java.util.Optional; 4 | 5 | public class OptionalIfPresentExample { 6 | public static void main(String[] args) { 7 | 8 | // String value optional 9 | Optional string = Optional.ofNullable("12345"); 10 | 11 | // converting string to number 12 | Optional numberOptional = string.map(value -> Integer.parseInt(value)); 13 | 14 | // printing the number using ifPresent() 15 | numberOptional.ifPresent(newValue -> System.out.println(newValue)); 16 | 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/large/Largest3NumbersOptimizedExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.large; 2 | 3 | public class Largest3NumbersOptimizedExample1 { 4 | 5 | public static void main(String[] args) { 6 | 7 | int number1 = 1000; 8 | int number2 = 2000; 9 | int number3 = 300; 10 | 11 | int max = number1; 12 | 13 | if (number1 >= number2 && number1 >= number3) { 14 | max = number1; 15 | } else if (number2 >= number3) { 16 | max = number2; 17 | } else { 18 | max = number3; 19 | } 20 | 21 | System.out.println(max + " is biggest number"); 22 | } 23 | 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/count/CountNoCharExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.count; 2 | 3 | public class CountNoCharExample2 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String givenString = "hello world"; 8 | 9 | char givenChar = 'l'; 10 | 11 | int strOriginalLength = givenString.length(); 12 | 13 | String replacedString = givenString.replace(String.valueOf(givenChar), ""); 14 | 15 | int count = strOriginalLength - replacedString.length(); 16 | 17 | System.out.println("no of occurrences of char 'l' is "+count); 18 | } 19 | 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/collections/hashmap/print/HashMapPrintExample4.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.collections.hashmap.print; 2 | 3 | import java.util.HashMap; 4 | import java.util.Map; 5 | import java.util.Set; 6 | 7 | public class HashMapPrintExample4 { 8 | 9 | public static void main(String[] args) { 10 | 11 | Map map = new HashMap<>(); 12 | 13 | map.put(1, "one"); 14 | map.put(2, "two"); 15 | map.put(3, "three"); 16 | 17 | Set keys = map.keySet(); 18 | 19 | for(Integer key : keys) { 20 | System.out.println(key+" - "+map.get(key)); 21 | } 22 | 23 | } 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/exception/inputmismatchexception/InputMismatchExceptionExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.exception.inputmismatchexception; 2 | 3 | import java.util.Scanner; 4 | 5 | public class InputMismatchExceptionExample { 6 | 7 | public static void main(String[] args) { 8 | 9 | Scanner scanner = new Scanner(System.in); 10 | 11 | System.out.println("Please enter a number"); 12 | int number = scanner.nextInt(); 13 | 14 | if (number % 2 == 0) { 15 | System.out.println(number + " is even"); 16 | } else { 17 | System.out.println(number + " is odd"); 18 | } 19 | 20 | } 21 | 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/foreach/NormalForEachListExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.foreach; 2 | 3 | import java.util.ArrayList; 4 | import java.util.List; 5 | 6 | public class NormalForEachListExample { 7 | 8 | public static void main(String[] args) { 9 | 10 | List list = new ArrayList<>(); 11 | 12 | list.add("one"); 13 | list.add("two"); 14 | list.add("three"); 15 | list.add("four"); 16 | list.add("five"); 17 | 18 | for (String s : list) { 19 | System.out.println(s); 20 | } 21 | 22 | } 23 | 24 | } 25 | 26 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/integer/IntegerToUnsignedLongExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.integer; 2 | 3 | public class IntegerToUnsignedLongExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | Long long1 = Integer.toUnsignedLong(10); 8 | System.out.println("unsigned long value for int 10 is " + long1); 9 | 10 | Long long2 = Integer.toUnsignedLong(4294967); 11 | System.out.println("unsigned long value for int 4294967 is " + long2); 12 | 13 | Long long3 = Integer.toUnsignedLong(100000); 14 | System.out.println("unsigned long value for int 10 is " + long3); 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/streams/foreach/StreamForBreak.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.streams.foreach; 2 | 3 | import java.util.Arrays; 4 | import java.util.List; 5 | 6 | public class StreamForBreak { 7 | 8 | public static void main(String[] args) { 9 | 10 | List list = Arrays.asList("one", "two", "three", "seven", "nine", "ten"); 11 | 12 | for (int i = 0; i < list.size(); i++) { 13 | if (list.get(i).length() > 3) { 14 | 15 | break; 16 | } 17 | System.out.println(list.get(i)); 18 | 19 | } 20 | 21 | } 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/files/printwriter/newline/PrintWriterNewLine.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.files.printwriter.newline; 2 | 3 | import java.io.PrintWriter; 4 | 5 | public class PrintWriterNewLine { 6 | 7 | public static void main(String[] args) { 8 | 9 | PrintWriter printWriter = new PrintWriter(System.out); 10 | 11 | printWriter.write("this is the first line"); 12 | printWriter.write("\n"); 13 | printWriter.write("this is the second line"); 14 | printWriter.write("\n"); 15 | printWriter.write("third line"); 16 | 17 | printWriter.flush(); 18 | 19 | printWriter.close(); 20 | 21 | } 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/conversion/sql/SQLDateToLocalDateExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.conversion.sql; 2 | 3 | import java.sql.Date; 4 | import java.time.LocalDate; 5 | 6 | public class SQLDateToLocalDateExample { 7 | 8 | public static void main(String[] args) { 9 | 10 | // Creating sql date 11 | Date sqlDate = Date.valueOf("2020-12-31"); 12 | 13 | // converting sql date to localdate using toLocalDate() method. 14 | LocalDate localDate1 = sqlDate.toLocalDate(); 15 | 16 | // printing the local date. 17 | System.out.println("Local Date 1 : "+localDate1); 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/conversion/totimestamp/LocalDateToTimeStampExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.conversion.totimestamp; 2 | 3 | import java.sql.Timestamp; 4 | import java.time.LocalDate; 5 | 6 | public class LocalDateToTimeStampExample { 7 | 8 | public static void main(String[] args) { 9 | 10 | 11 | LocalDate localDate = LocalDate.now(); 12 | 13 | System.out.println("Local Date - "+localDate); 14 | 15 | Timestamp timestamp = Timestamp.valueOf(localDate.atStartOfDay()); 16 | 17 | System.out.println("Timestamp from localdate is "+timestamp); 18 | 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/large/Largest3NumbersExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.large; 2 | 3 | public class Largest3NumbersExample1 { 4 | 5 | public static void main(String[] args) { 6 | 7 | int number1 = 10; 8 | int number2 = 20; 9 | int number3 = 30; 10 | 11 | if (number1 >= number2 && number1 >= number3) { 12 | System.out.println(number1 + " is the biggest"); 13 | } else if (number2 >= number1 && number2 >= number3) { 14 | System.out.println(number2 + " is the biggest"); 15 | } else { 16 | System.out.println(number3 + " is the biggest"); 17 | } 18 | 19 | } 20 | 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/StringCodepoinExampleToConvertStream.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings; 2 | 3 | import java.util.stream.IntStream; 4 | 5 | public class StringCodepoinExampleToConvertStream { 6 | 7 | public static void main(String[] args) { 8 | 9 | String str = "Code Points as Stream"; 10 | 11 | System.out.println("Input string value : "+str); 12 | 13 | IntStream intStream = str.codePoints(); 14 | 15 | System.out.println("Printing each char from string as ASCII value"); 16 | intStream.forEach(value -> System.out.print(value+" ")); 17 | 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/booleanarray/BooleanArrayExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.booleanarray; 2 | 3 | public class BooleanArrayExample2 { 4 | 5 | public static void main(String[] args) { 6 | 7 | // way 1 8 | boolean[] array1 = { false, true, true }; 9 | 10 | // way 2 11 | boolean[] array2 = new boolean[4]; 12 | 13 | array2[0] = true; 14 | array2[1] = false; 15 | array2[2] = true; 16 | array2[3] = false; 17 | 18 | // way 3 19 | boolean[] array3 = new boolean[5]; 20 | 21 | for (int i = 0; i < array3.length; i++) { 22 | array3[i] = i % 2 == 0; 23 | } 24 | 25 | } 26 | } 27 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/chars/AddCharToStringExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.chars; 2 | 3 | public class AddCharToStringExample2 { 4 | 5 | public static void main(String[] args) { 6 | 7 | // adding the char at the start of string 8 | String addingCharAtStart = 'A' + " hello"; 9 | 10 | // adding multiple chars at the start of the string 11 | String addingCharsAtStart = 'A' + 'B'+ " hello"; 12 | 13 | System.out.println("adding single char to the start of the string - "+addingCharAtStart); 14 | System.out.println("adding miltiple chars to the start of the string - "+addingCharsAtStart); 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/exception/FinallyBlockAfterReturn.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.exception; 2 | 3 | public class FinallyBlockAfterReturn { 4 | 5 | public static void main(String[] args) { 6 | 7 | int returnedStatus = process(); 8 | System.out.println("Returned value : "+returnedStatus); 9 | 10 | } 11 | public static int process() { 12 | 13 | try { 14 | return 1; 15 | } catch (Exception e) { 16 | return 2; 17 | } finally { 18 | System.out.println("Executing Finally block after return statement."); 19 | } 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/files/directory/CurrentDirectoryPathGetExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.files.directory; 2 | 3 | import java.nio.file.Path; 4 | import java.nio.file.Paths; 5 | 6 | public class CurrentDirectoryPathGetExample { 7 | 8 | public static void main(String[] args) { 9 | 10 | // Current location from path. 11 | Path currentPath = Paths.get(""); 12 | 13 | // getting the location from Path.toAbsolutePath() 14 | String currentLocation = currentPath.toAbsolutePath().toString(); 15 | 16 | 17 | System.out.println("Current working directoruy : " + currentLocation); 18 | 19 | } 20 | 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/instant/InstantParseExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.instant; 2 | 3 | import java.time.Instant; 4 | 5 | public class InstantParseExample { 6 | public static void main(String[] args) { 7 | 8 | // Creating instant object from parse() 9 | Instant instantFromStr1 = Instant.parse("2020-11-29T13:35:30.01Z"); 10 | System.out.println("Instant 1 from string using parse() : " + instantFromStr1); 11 | 12 | Instant instantFromStr2 = Instant.parse("2020-12-29T13:35:31.00Z"); 13 | System.out.println("Instant 2 from string using parse() : " + instantFromStr2); 14 | } 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/intstream/toList/IntStreamToListExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.intstream.toList; 2 | 3 | import java.util.LinkedList; 4 | import java.util.List; 5 | import java.util.stream.Collectors; 6 | import java.util.stream.IntStream; 7 | import java.util.stream.Stream; 8 | 9 | public class IntStreamToListExample2 { 10 | 11 | public static void main(String[] args) { 12 | 13 | IntStream evenIntStream = IntStream.iterate(0, i -> i + 2); 14 | 15 | List list = evenIntStream.limit(100).boxed().toList(); 16 | 17 | System.out.println("list size : " + list.size()); 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/optional/OptionalOrElse.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.optional; 2 | 3 | import java.util.Optional; 4 | 5 | public class OptionalOrElse { 6 | public static void main(String[] args) { 7 | 8 | Optional o1 = Optional.ofNullable(null); 9 | 10 | String value = o1.orElse("Default One"); 11 | 12 | System.out.println("Fetching the value from orElse() : "+value); 13 | 14 | Optional intOptional = Optional.empty(); 15 | 16 | int defaultValue = intOptional.orElse(15); 17 | 18 | System.out.println("Int default value :"+defaultValue); 19 | 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/optional/OptionalflatmapExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.optional; 2 | 3 | import java.util.Optional; 4 | 5 | public class OptionalflatmapExample { 6 | public static void main(String[] args) { 7 | 8 | Optional optional1 = Optional.of("Hello Java 8 Optional"); 9 | Optional> optional2 = Optional.of(optional1); 10 | 11 | System.out.println("Optional2 value : " + optional2); 12 | 13 | Optional output = optional2.flatMap(value -> value.map(String::toLowerCase)); 14 | 15 | System.out.println("output value : " + output); 16 | 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/streams/filter/FilterExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.streams.filter; 2 | 3 | import java.util.Arrays; 4 | import java.util.List; 5 | import java.util.stream.Collectors; 6 | 7 | public class FilterExample { 8 | 9 | public static void main(String[] args) { 10 | 11 | List numbers = Arrays.asList(10,50,30,18,35); 12 | 13 | List evenNumbers = numbers.stream().filter(number -> number % 2 == 0).collect(Collectors.toList()); 14 | 15 | System.out.println("After applying the filter function : "+evenNumbers); 16 | 17 | 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/booleanarray/BooleanArrayExample5.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.booleanarray; 2 | 3 | public class BooleanArrayExample5 { 4 | 5 | public static void main(String[] args) { 6 | 7 | boolean[] array5 = new boolean[5]; 8 | 9 | System.out.println("Default value of array5 at index 1 is - " + array5[1]); 10 | 11 | System.out.println("Setting to true for all indexes of array 5 using simple for loop"); 12 | for (int i = 0; i < array5.length; i++) { 13 | array5[i] = true; 14 | } 15 | System.out.println("Now Default value of array5 at index 1 is - " + array5[1]); 16 | 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/conversion/CalenderToLocalDateExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.conversion; 2 | 3 | import java.time.LocalDate; 4 | import java.time.ZoneId; 5 | import java.util.Calendar; 6 | import java.util.Date; 7 | 8 | public class CalenderToLocalDateExample { 9 | 10 | public static void main(String[] args) { 11 | 12 | Calendar cal = Calendar.getInstance(); 13 | Date input = cal.getTime(); 14 | LocalDate la = input.toInstant().atZone(ZoneId.systemDefault()).toLocalDate(); 15 | 16 | System.out.println("Calender to LocalDate : "+la); 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/bytearray/Base64Decode.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.bytearray; 2 | 3 | import java.nio.charset.CharacterCodingException; 4 | import java.util.Base64; 5 | 6 | public class Base64Decode { 7 | 8 | public static void main(String[] args) throws CharacterCodingException { 9 | 10 | // creating string 11 | String inputStr = "javaprogrmto.com जावा"; 12 | 13 | // java 8 string to byte[] 14 | byte[] array = Base64.getDecoder().decode(inputStr); 15 | 16 | // printing byte array 17 | for (int j = 0; j < array.length; j++) { 18 | System.out.print(" " + array[j]); 19 | } 20 | 21 | } 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/streams/reduce/StreamReduceExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.streams.reduce; 2 | 3 | import java.util.Arrays; 4 | import java.util.List; 5 | import java.util.Optional; 6 | 7 | public class StreamReduceExample { 8 | 9 | public static void main(String[] args) { 10 | 11 | List numbers = Arrays.asList(1, 2, 3, 4, 5, 6, 7); 12 | 13 | Optional sumOptional = numbers.stream().reduce((currentSum, nextValue) -> currentSum + nextValue); 14 | 15 | if(sumOptional.isPresent()) { 16 | System.out.println("sum of first 7 numbers is "+sumOptional.get()); 17 | } 18 | } 19 | 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/StringCodepointCountExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings; 2 | 3 | public class StringCodepointCountExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | String heartString = "\uD83D\uDC93\uD83D\uDC93\uD83D\uDC93\uD83D\uDC93"; 8 | 9 | System.out.println("Input string value : "+heartString); 10 | 11 | // Getting count of code points for index 0 to 4 12 | int countpointsCount = heartString.codePointCount(0, heartString.length()); 13 | 14 | System.out.println("Code points count for indexs range (0, 4) : "+countpointsCount); 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/returns/ArrayReturnExample4.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.returns; 2 | 3 | import java.util.Arrays; 4 | 5 | public class ArrayReturnExample4 { 6 | 7 | public static void main(String[] args) { 8 | 9 | int[][] multiArray = getMultiArray(); 10 | 11 | System.out.println("Returned Multi dimentional array values : "); 12 | for(int[] a : multiArray) { 13 | System.out.println( Arrays.toString(a)); 14 | } 15 | 16 | } 17 | 18 | // returning multi dimens 19 | public static int[][] getMultiArray() { 20 | 21 | int[][] multi = { { 1, 2, 3 }, { 4, 5, 6 } }; 22 | return multi; 23 | 24 | } 25 | } 26 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/exception/inputmismatchexception/InputMismatchExceptionExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.exception.inputmismatchexception; 2 | 3 | import java.math.BigDecimal; 4 | import java.util.Scanner; 5 | 6 | public class InputMismatchExceptionExample2 { 7 | 8 | public static void main(String[] args) { 9 | 10 | Scanner scanner = new Scanner(System.in); 11 | 12 | System.out.println("Enter BigDecimal array size: "); 13 | int size = scanner.nextInt(); 14 | 15 | BigDecimal[] array = new BigDecimal[size]; 16 | 17 | for (int i = 0; i < size; i++) { 18 | array[i] = scanner.nextBigDecimal(); 19 | } 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/collectors/tolist/StreamCollectToListExample5.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.collectors.tolist; 2 | 3 | import java.util.List; 4 | import java.util.stream.Collectors; 5 | import java.util.stream.IntStream; 6 | 7 | public class StreamCollectToListExample5 { 8 | 9 | public static void main(String[] args) { 10 | 11 | IntStream infiniteStream = IntStream.iterate(1000, i -> i + 1000); 12 | 13 | List numbersList = infiniteStream.limit(5).boxed().collect(Collectors.toList()); 14 | 15 | System.out.println("infinite stream collect to ArrayList output : " + numbersList); 16 | 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/conversion/totimestamp/LocalDateTimeToTimeStampExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.conversion.totimestamp; 2 | 3 | import java.sql.Timestamp; 4 | import java.time.LocalDateTime; 5 | 6 | public class LocalDateTimeToTimeStampExample { 7 | 8 | public static void main(String[] args) { 9 | 10 | 11 | LocalDateTime localDateTime = LocalDateTime.now(); 12 | 13 | System.out.println("Local Date Time - "+localDateTime); 14 | 15 | Timestamp timestamp = Timestamp.valueOf(localDateTime); 16 | 17 | System.out.println("Timestamp from localdatetime is "+timestamp); 18 | 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/maths/LCMOfLargeNumbers.java: -------------------------------------------------------------------------------- 1 | 2 | package com.javaprogramto.programs.maths; 3 | 4 | import java.math.BigInteger; 5 | 6 | public class LCMOfLargeNumbers { 7 | 8 | public static void main(String[] args) { 9 | 10 | BigInteger large1 = new BigInteger("123456789123456789123456"); 11 | BigInteger large2 = new BigInteger("987654321987654321987654"); 12 | 13 | BigInteger gcd = large1.gcd(large2); 14 | 15 | BigInteger multiply = large1.multiply(large2); 16 | 17 | BigInteger lcm = multiply.divide(gcd); 18 | 19 | System.out.println("Final LCM output: "+lcm.toString()); 20 | 21 | } 22 | 23 | } 24 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/todouble/StringToDoubleExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.todouble; 2 | 3 | public class StringToDoubleExample1 { 4 | 5 | public static void main(String[] args) { 6 | 7 | // double value in string format 8 | String to_double = "1234"; 9 | 10 | double doubleValue = Double.parseDouble(to_double); 11 | 12 | System.out.println("String to Double value : " + doubleValue); 13 | 14 | to_double = "100d"; 15 | 16 | doubleValue = Double.parseDouble(to_double); 17 | 18 | System.out.println("String to Double value with d in the string : " + doubleValue); 19 | 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/StringCodepointCountException.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings; 2 | 3 | public class StringCodepointCountException { 4 | 5 | public static void main(String[] args) { 6 | 7 | String heartString = "\uD83D\uDC93\uD83D\uDC93\uD83D\uDC93\uD83D\uDC93"; 8 | 9 | System.out.println("Input string value : "+heartString); 10 | 11 | // Getting count of code points for index 0 to 4 12 | int countpointsCount = heartString.codePointCount(-10, heartString.length()); 13 | 14 | System.out.println("Code points count for indexs range (0, 4) : "+countpointsCount); 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/StringStartsWithExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings; 2 | 3 | public class StringStartsWithExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | String s1 = "hello world"; 8 | 9 | boolean isStringStartsWithHello = s1.startsWith("hello"); 10 | 11 | System.out.println("String starts with hello or not : "+isStringStartsWithHello); 12 | System.out.println("Phone number starts with +91 "+"+91 12345678".startsWith("+678")); 13 | 14 | System.out.println("javaprogramto.com starts with java : "+"javaprogramto.com".startsWith("java")); 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/getdatetime/DateExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.getdatetime; 2 | 3 | import java.util.Date; 4 | 5 | public class DateExample { 6 | 7 | public static void main(String[] args) { 8 | 9 | // using new Date() 10 | Date currentDateTime = new Date(); 11 | System.out.println("Current date time using Date() : " + currentDateTime); 12 | 13 | // using System.currentTimeMillis() 14 | long milliSeconds = System.currentTimeMillis(); 15 | currentDateTime = new Date(milliSeconds); 16 | System.out.println("Current date time using System.currentTimeMillis() : " + currentDateTime); 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/collections/hashmap/print/HashMapPrintExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.collections.hashmap.print; 2 | 3 | import java.util.HashMap; 4 | import java.util.Iterator; 5 | import java.util.Map; 6 | 7 | public class HashMapPrintExample2 { 8 | 9 | public static void main(String[] args) { 10 | 11 | Map map = new HashMap<>(); 12 | 13 | map.put(1, "one"); 14 | map.put(2, "two"); 15 | map.put(3, "three"); 16 | 17 | Iterator> it = map.entrySet().iterator(); 18 | 19 | it.forEachRemaining( entry -> System.out.println(entry.getKey() + " - "+entry.getValue())); 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/skip/Skip10ValuesExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.skip; 2 | 3 | import java.util.List; 4 | import java.util.stream.Collectors; 5 | import java.util.stream.Stream; 6 | 7 | public class Skip10ValuesExample { 8 | public static void main(String[] args) { 9 | 10 | Stream numnerSeries = Stream.iterate(1, i -> i+ 1); 11 | 12 | List next20Numbers = numnerSeries.skip(10).limit(20).collect(Collectors.toList()); 13 | 14 | System.out.println("20 Numbers after skipping first 10 numbers"); 15 | next20Numbers.forEach(number -> System.out.println(number)); 16 | } 17 | } 18 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/permutations/StringPermutationsExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.permutations; 2 | 3 | public class StringPermutationsExample1 { 4 | 5 | public static void main(String[] args) { 6 | 7 | stringPermuteAndPrint("", "ABC"); 8 | } 9 | 10 | private static void stringPermuteAndPrint(String prefix, String str) { 11 | int n = str.length(); 12 | if (n == 0) { 13 | System.out.print(prefix + " "); 14 | } else { 15 | for (int i = 0; i < n; i++) { 16 | stringPermuteAndPrint(prefix + str.charAt(i), str.substring(i + 1, n) + str.substring(0, i)); 17 | } 18 | } 19 | } 20 | 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/StringCodepointBeforeExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings; 2 | 3 | public class StringCodepointBeforeExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | String str = "JavaProgramTo.com"; 8 | 9 | System.out.println("Input string value : "+str); 10 | 11 | int codepointBefore = str.codePointBefore(2); 12 | System.out.println("Code point for before index 2 : "+codepointBefore); 13 | 14 | codepointBefore = str.codePointBefore(str.length()); 15 | System.out.println("Code point for before index "+str.length()+": "+codepointBefore); 16 | } 17 | } 18 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/collections/hashmap/print/HashMapPrintExample5.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.collections.hashmap.print; 2 | 3 | import java.util.HashMap; 4 | import java.util.Map; 5 | import java.util.Set; 6 | import java.util.function.BiConsumer; 7 | 8 | public class HashMapPrintExample5 { 9 | 10 | public static void main(String[] args) { 11 | 12 | Map map = new HashMap<>(); 13 | 14 | map.put(1, "one"); 15 | map.put(2, "two"); 16 | map.put(3, "three"); 17 | 18 | BiConsumer printBiConsumer = (key, value) -> System.out.println(key+" - "+value); 19 | 20 | map.forEach(printBiConsumer); 21 | } 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/streams/infinite/StreamIterateExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.streams.infinite; 2 | 3 | import java.util.List; 4 | import java.util.stream.Collectors; 5 | import java.util.stream.Stream; 6 | 7 | public class StreamIterateExample { 8 | 9 | public static void main(String[] args) { 10 | 11 | // Creating a infinite Stream 12 | Stream even10Numbers = Stream.iterate(0, i -> i +2); 13 | 14 | List first10Numbers = even10Numbers.limit(10).collect(Collectors.toList()); 15 | 16 | System.out.println("even10Numbers with limit 10 : "+first10Numbers); 17 | 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/maptolist/MapKeysToListExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.maptolist; 2 | 3 | import java.util.ArrayList; 4 | import java.util.HashMap; 5 | import java.util.List; 6 | import java.util.Map; 7 | 8 | public class MapKeysToListExample { 9 | 10 | public static void main(String[] args) { 11 | 12 | Map idNames = new HashMap<>(); 13 | 14 | idNames.put(100, "modi"); 15 | idNames.put(101, "trump"); 16 | idNames.put(102, "putin"); 17 | 18 | List ids =new ArrayList<>(idNames.keySet()); 19 | 20 | ids.forEach(id -> System.out.println(id)); 21 | } 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/compare/StringDoesnotEqual.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings.compare; 2 | 3 | public class StringDoesnotEqual { 4 | 5 | public static void main(String[] args) { 6 | 7 | String status = getValidationStatus(10); 8 | System.out.println("status : "+status); 9 | 10 | if (status.intern() != "Failure") { 11 | System.out.println("Valid age"); 12 | } else { 13 | System.out.println("Invalid age"); 14 | } 15 | 16 | } 17 | 18 | public static String getValidationStatus(int age) { 19 | 20 | if (age < 18) { 21 | return new String("Failure"); 22 | } 23 | 24 | return new String ("Success"); 25 | } 26 | } 27 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/anymatch/AnyMatchEvenExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.anymatch; 2 | 3 | import java.util.stream.Stream; 4 | 5 | public class AnyMatchEvenExample { 6 | 7 | public static void main(String[] args) { 8 | 9 | Integer[] numbers = {1, 3, 5, 7, 8, 9}; 10 | 11 | Stream intStream = Stream.of(numbers); 12 | 13 | boolean matchFound = intStream.anyMatch(number -> number % 2 == 0); 14 | 15 | if(matchFound){ 16 | System.out.println("int array has even number"); 17 | } else { 18 | System.out.println("int array has no even number"); 19 | } 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/comparator/reverse/ComparatorReverse2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.comparator.reverse; 2 | 3 | import java.util.Arrays; 4 | import java.util.Comparator; 5 | import java.util.List; 6 | import java.util.stream.Collectors; 7 | 8 | public class ComparatorReverse2 { 9 | 10 | public static void main(String[] args) { 11 | 12 | List list = Arrays.asList("1", "3", "2"); 13 | 14 | System.out.println("Original list - " + list); 15 | 16 | List sortedList = list.stream().sorted(Comparator.reverseOrder()).collect(Collectors.toList()); 17 | 18 | System.out.println("Sorted list - " + sortedList); 19 | 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/optional/OptionalOrElseGet.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.optional; 2 | 3 | import java.util.Optional; 4 | 5 | public class OptionalOrElseGet { 6 | public static void main(String[] args) { 7 | 8 | Optional o1 = Optional.ofNullable(null); 9 | 10 | String value = o1.orElseGet(() -> "Default One from supplier"); 11 | 12 | System.out.println("Fetching the value from orElseGet() : " + value); 13 | 14 | Optional intOptional = Optional.of(134); 15 | 16 | int defaultValue = intOptional.orElseGet(() -> 15); 17 | 18 | System.out.println("orElseGet Int default value :" + defaultValue); 19 | 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/skip/SkipNegativeIndexExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.skip; 2 | 3 | import java.util.List; 4 | import java.util.stream.Collectors; 5 | import java.util.stream.Stream; 6 | 7 | public class SkipNegativeIndexExample { 8 | public static void main(String[] args) { 9 | 10 | Stream numbers = Stream.of(1, 2, 3); 11 | 12 | List expectingError = numbers 13 | .skip(-25) 14 | .collect(Collectors.toList()); 15 | 16 | System.out.println("skipping first 5 even Numbers"); 17 | expectingError.forEach(number -> System.out.println(number)); 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/todouble/StringToDoubleExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.todouble; 2 | 3 | public class StringToDoubleExample2 { 4 | 5 | public static void main(String[] args) { 6 | 7 | // double value in string format 8 | String to_double = "1234"; 9 | 10 | Double doubleValue = Double.valueOf(to_double); 11 | 12 | System.out.println("String to Double value with valueOf() : " + doubleValue); 13 | 14 | to_double = "100d"; 15 | 16 | doubleValue = Double.valueOf(to_double); 17 | 18 | System.out.println("String to Double value with d in the string using valueOf() : " + doubleValue); 19 | 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/empty/ReturnEmptyArrayExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.empty; 2 | 3 | public class ReturnEmptyArrayExample2 { 4 | 5 | public static void main(String[] args) { 6 | 7 | if (true) { 8 | int[] array1 = emptyArrayWIthCurlyBraces(); 9 | System.out.println("Length of int array 1 : " + array1.length); 10 | } 11 | 12 | if (100 > 0) { 13 | int[] array2 = emptyArrayWIthCurlyBraces(); 14 | System.out.println("Length of int array 2 : " + array2.length); 15 | } 16 | 17 | } 18 | 19 | public static int[] emptyArrayWIthCurlyBraces() { 20 | 21 | int[] emptyArray = {}; 22 | 23 | return emptyArray; 24 | } 25 | } 26 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/collections/set/add/HashSetAddExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.collections.set.add; 2 | 3 | import java.util.HashSet; 4 | import java.util.Set; 5 | 6 | public class HashSetAddExample { 7 | 8 | public static void main(String[] args) { 9 | 10 | Set set = new HashSet<>(); 11 | 12 | boolean isAdded = set.add(10); 13 | System.out.println("Is 10 added? " + isAdded); 14 | 15 | isAdded = set.add(10); 16 | System.out.println("Is 10 added again? " + isAdded); 17 | 18 | isAdded = set.add(20); 19 | System.out.println("Is 20 added? " + isAdded); 20 | 21 | System.out.println("Set values : "+set); 22 | 23 | } 24 | 25 | } 26 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/localdate/StringToLocalDateExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.localdate; 2 | 3 | import java.time.LocalDate; 4 | 5 | // String to LocalDate in java 8 6 | public class StringToLocalDateExample { 7 | 8 | public static void main(String[] args) { 9 | 10 | // Example 1 11 | String dateInStr = "2021-01-01"; 12 | LocalDate date1 = LocalDate.parse(dateInStr); 13 | System.out.println("String to LocalDate : " + date1); 14 | 15 | // Example 2 16 | String dateInStr2 = "2025-11-30"; 17 | LocalDate date2 = LocalDate.parse(dateInStr2); 18 | System.out.println("String to LocalDate : " + date2); 19 | 20 | } 21 | 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/streams/parallel/streams/ParallelStreamCreation.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.streams.parallel.streams; 2 | 3 | import java.util.Arrays; 4 | import java.util.List; 5 | import java.util.concurrent.ForkJoinPool; 6 | import java.util.stream.Stream; 7 | 8 | public class ParallelStreamCreation { 9 | 10 | public static void main(String[] args) { 11 | 12 | List intList = Arrays.asList(10, 20, 30, 40, 50); 13 | 14 | Stream parallelStream = intList.parallelStream(); 15 | 16 | ForkJoinPool.commonPool(); 17 | 18 | parallelStream.forEach(value -> System.out.println(value)); 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/maths/QuotientRemainderExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.maths; 2 | 3 | public class QuotientRemainderExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | // Creating int variable for number 1 8 | int number1 = 200; 9 | 10 | // Creating int variable for number 2 11 | int number2 = 50; 12 | 13 | // Calculating the quotient 14 | int quotient = number1 / number2; 15 | 16 | // Calculating the remainder 17 | int remainder = number1 % number2; 18 | 19 | System.out.println("Quotient value: "+quotient); 20 | System.out.println("Remainder value with zero: "+remainder); 21 | 22 | } 23 | 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/numbers/math/MathAbsoluteExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.numbers.math; 2 | 3 | public class MathAbsoluteExample1 { 4 | 5 | public static void main(String[] args) { 6 | 7 | // for integer primitive values 8 | int i = -100; 9 | int absValueofI = Math.abs(i); 10 | 11 | System.out.println("abs value of " + i + " is " + absValueofI); 12 | 13 | i = 200; 14 | absValueofI = Math.abs(i); 15 | 16 | System.out.println("abs value of " + i + " is " + absValueofI); 17 | 18 | i = -0; 19 | absValueofI = Math.abs(i); 20 | 21 | System.out.println("abs value of " + i + " is " + absValueofI); 22 | 23 | } 24 | 25 | } 26 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/numbers/math/MathAbsoluteExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.numbers.math; 2 | 3 | public class MathAbsoluteExample2 { 4 | 5 | public static void main(String[] args) { 6 | 7 | // for long primitive values 8 | long l = -100; 9 | long absValueofL = Math.abs(l); 10 | 11 | System.out.println("abs value of " + l + " is " + absValueofL); 12 | 13 | l = 200; 14 | absValueofL = Math.abs(l); 15 | 16 | System.out.println("abs value of " + l + " is " + absValueofL); 17 | 18 | l = -0; 19 | absValueofL = Math.abs(l); 20 | 21 | System.out.println("abs value of " + l + " is " + absValueofL); 22 | 23 | } 24 | 25 | } 26 | -------------------------------------------------------------------------------- /.settings/.jsdtscope: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/find/LinearSearch.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.find; 2 | 3 | public class LinearSearch { 4 | 5 | public static void main(String[] args) { 6 | 7 | int[] array = {6, 7, 10, 5, 70, 9}; 8 | 9 | boolean found = false; 10 | 11 | int valueToBeFound = 5; 12 | 13 | for(int value : array){ 14 | 15 | if( value == valueToBeFound){ 16 | found = true; 17 | } 18 | } 19 | 20 | if(found){ 21 | System.out.println("value 5 is present"); 22 | } else { 23 | System.out.println("value 5 is not present"); 24 | } 25 | } 26 | } 27 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/exit/JavaProgramExitExample4.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.exit; 2 | 3 | public class JavaProgramExitExample4 { 4 | 5 | public static void main(String[] args) { 6 | 7 | System.out.println("first line from main method"); 8 | 9 | int number = 10; 10 | String value = getValue(number); 11 | System.out.println(value); 12 | System.out.println("last line from main method"); 13 | } 14 | 15 | private static String getValue(int number) { 16 | 17 | System.out.println("statement 1"); 18 | 19 | if(number % 2 == 0) { 20 | return "even number"; 21 | } 22 | else { 23 | return "odd number"; 24 | } 25 | } 26 | 27 | } 28 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/todouble/StringToDoubleExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.todouble; 2 | 3 | public class StringToDoubleExample3 { 4 | 5 | public static void main(String[] args) { 6 | 7 | // double value in string format 8 | String to_double = "1234"; 9 | 10 | Double doubleValue = new Double(to_double); 11 | 12 | System.out.println("String to Double value with Double constructor : " + doubleValue); 13 | 14 | to_double = "100d"; 15 | 16 | doubleValue = new Double(to_double); 17 | 18 | System.out.println("String to Double value with d in the string using Double constructor : " + doubleValue); 19 | 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/sort/reverse/ArraySortReverseInts.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.sort.reverse; 2 | 3 | import java.util.Arrays; 4 | import java.util.Collections; 5 | 6 | public class ArraySortReverseInts { 7 | 8 | public static void main(String[] args) { 9 | 10 | Integer[] ints = new Integer[5]; 11 | ints[0] = 20; 12 | ints[1] = 50; 13 | ints[2] = 40; 14 | ints[3] = 10; 15 | ints[4] = 30; 16 | 17 | System.out.println("Integer array before sort - " + Arrays.toString(ints)); 18 | 19 | Arrays.sort(ints, Collections.reverseOrder()); 20 | 21 | System.out.println("Integer array after sort - " + Arrays.toString(ints)); 22 | 23 | } 24 | 25 | } 26 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/files/directory/CurrentDirectoryFileSystemsExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.files.directory; 2 | 3 | import java.nio.file.FileSystems; 4 | import java.nio.file.Path; 5 | 6 | public class CurrentDirectoryFileSystemsExample { 7 | 8 | public static void main(String[] args) { 9 | 10 | // Current location from FileSystems. 11 | Path currentPath = FileSystems.getDefault().getPath("."); 12 | 13 | // getting the location from Path.toAbsolutePath() 14 | String currentLocation = currentPath.toAbsolutePath().normalize().toString(); 15 | 16 | 17 | System.out.println("Current working directoruy : " + currentLocation); 18 | 19 | } 20 | 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/keywords/extend/ClasesExtendsExamples.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.keywords.extend; 2 | 3 | public class ClasesExtendsExamples { 4 | 5 | public static void main(String[] args) { 6 | 7 | HondaCar hondaCar = new HondaCar(); 8 | int noOfWheels = hondaCar.getNoOfWheels(); 9 | System.out.println("Honda car wheels : " + noOfWheels); 10 | 11 | } 12 | } 13 | 14 | class Car { 15 | 16 | int noOfWheels = 4; 17 | } 18 | 19 | class HondaCar extends Car { 20 | 21 | public int getNoOfWheels() { 22 | return this.noOfWheels; 23 | } 24 | } 25 | /* 26 | class HybridCar extends Car , HondaCar{ 27 | 28 | } 29 | */ 30 | 31 | class SkodaCar extends Car { 32 | 33 | } -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/conversions/string/StringtoStringArraySplit.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.conversions.string; 2 | 3 | public class StringtoStringArraySplit { 4 | 5 | public static void main(String[] args) { 6 | 7 | // input string 8 | String input = "javaprogramto.com"; 9 | 10 | // spliting string into string array using split() method. 11 | String[] stringArray = input.split(""); 12 | 13 | // printing the values of string array 14 | for (String string : stringArray) { 15 | System.out.println(string); 16 | } 17 | 18 | System.out.println(stringArray.length); 19 | System.out.println(input.length()); 20 | 21 | } 22 | 23 | } 24 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/arrays/average/ArrayAverage.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.arrays.average; 2 | 3 | public class ArrayAverage { 4 | 5 | public static void main(String[] args) { 6 | 7 | // create an array 8 | int[] array = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 }; 9 | 10 | // getting array length 11 | int length = array.length; 12 | 13 | // default sium value. 14 | int sum = 0; 15 | 16 | // sum of all values in array using for loop 17 | for (int i = 0; i < array.length; i++) { 18 | sum += array[i]; 19 | } 20 | 21 | double average = sum / length; 22 | 23 | System.out.println("Average of array : "+average); 24 | 25 | } 26 | 27 | } 28 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/w3schools/programs/ascii/StringToAsciiUSBytes.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.w3schools.programs.ascii; 2 | 3 | import java.nio.charset.StandardCharsets; 4 | import java.util.Arrays; 5 | 6 | public class StringToAsciiUSBytes { 7 | 8 | public static void main(String[] args) { 9 | 10 | String input = "ascii US bytes"; 11 | 12 | // converting string to bytes array. 13 | byte[] bytesArray = input.getBytes(StandardCharsets.US_ASCII); 14 | 15 | // bytes array to sscii string. 16 | String asciiStr = Arrays.toString(bytesArray); 17 | 18 | System.out.println("String to ASCII with US_ASCII : "+asciiStr); 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/timestamp/CurrentTimestampExample6.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.timestamp; 2 | 3 | import java.time.ZoneId; 4 | import java.time.ZonedDateTime; 5 | import java.time.format.DateTimeFormatter; 6 | 7 | public class CurrentTimestampExample6 { 8 | 9 | public static void main(String[] args) { 10 | 11 | ZoneId zoneId = ZoneId.systemDefault(); 12 | ZonedDateTime localDateTime = ZonedDateTime.now(zoneId); 13 | 14 | DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss SSS"); 15 | 16 | String timestamp = formatter.format(localDateTime); 17 | 18 | System.out.println("timestamp now : " + timestamp); 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/integer/IntegerCompareUnsignedExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.integer; 2 | 3 | public class IntegerCompareUnsignedExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | Integer integer1 = Integer.compareUnsigned(10, 20); 8 | System.out.println("Result of comparing two unsigned values (10, 20) : " + integer1); 9 | 10 | Integer integer2 = Integer.compareUnsigned(20, 10); 11 | System.out.println("Result of comparing two unsigned values (20, 10) : " + integer2); 12 | 13 | Integer integer3 = Integer.compareUnsigned(10, 10); 14 | System.out.println("Result of comparing two unsigned values (10, 10) : " + integer3); 15 | } 16 | } 17 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/streams/filter/ifelse/Java8StreammultipleIfExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.streams.filter.ifelse; 2 | 3 | import java.util.Arrays; 4 | import java.util.List; 5 | import java.util.stream.Collectors; 6 | 7 | public class Java8StreammultipleIfExample { 8 | 9 | public static void main(String[] args) { 10 | 11 | List numbersList = Arrays.asList(10, 13, 15, 20, 24, 16, 17, 100); 12 | 13 | List evenList = numbersList.stream() 14 | .filter(number -> number > 20) 15 | .filter(number -> number % 2 == 0) 16 | .collect(Collectors.toList()); 17 | 18 | System.out.println("Even numbers list - " + evenList); 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/scanner/close/ScannerCloseExample4.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.scanner.close; 2 | 3 | import java.util.Scanner; 4 | 5 | public class ScannerCloseExample4 { 6 | 7 | public static void main(String[] args) { 8 | Scanner scanner = new Scanner(System.in); 9 | 10 | System.out.println("Enter your birth year"); 11 | int year = scanner.nextInt(); 12 | 13 | System.out.println("Enter your age "); 14 | int age = scanner.nextInt(); 15 | 16 | scanner.close(); 17 | 18 | System.out.println("Given age and year are (" + age + "," + year + ")"); 19 | 20 | System.out.println("Enter your name "); 21 | String name = scanner.next(); 22 | } 23 | } 24 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/setall/LongArraySetAllExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.setall; 2 | 3 | import java.util.Arrays; 4 | 5 | public class LongArraySetAllExample { 6 | 7 | public static void main(String[] args) { 8 | 9 | // Creating a long array with default values 10 | long[] longArray = new long[7]; 11 | 12 | System.out.println("original long array with default values : "+ Arrays.toString(longArray)); 13 | 14 | // setting values to longArray using setAll() method 15 | Arrays.setAll(longArray, i -> i + 10 * 20); 16 | 17 | System.out.println("Long array.setAll(long) output: "+ Arrays.toString(longArray)); 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/getdatetime/SimpleDateFormatExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.getdatetime; 2 | 3 | import java.text.SimpleDateFormat; 4 | import java.util.Date; 5 | 6 | public class SimpleDateFormatExample { 7 | 8 | public static void main(String[] args) { 9 | 10 | // current date custom format 11 | SimpleDateFormat dateFormatter = new SimpleDateFormat("yyyy-MM-dd hh:mm"); 12 | 13 | // current date and time 14 | Date currentDate = new Date(); 15 | 16 | // Util Date to String using format() 17 | String strDate = dateFormatter.format(currentDate); 18 | 19 | System.out.println("Current Date using SimpleDateFormat : "+strDate); 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/optional/OfNullableExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.optional; 2 | 3 | import java.util.Optional; 4 | 5 | public class OfNullableExample { 6 | public static void main(String[] args) { 7 | 8 | // Creating optional 9 | Optional optional = Optional.ofNullable("javaprogramto.com"); 10 | 11 | System.out.println("Checking if optional has value with isEmpty() method"); 12 | System.out.println("isEmpty value : "+optional.isPresent()); 13 | 14 | // empty optional 15 | Optional emptyOptional = Optional.ofNullable(null); 16 | System.out.println("isPresent value for empty optional : "+emptyOptional.isPresent()); 17 | 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/skip/Skip5EvenNumbersExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.skip; 2 | 3 | import java.util.List; 4 | import java.util.stream.Collectors; 5 | import java.util.stream.Stream; 6 | 7 | public class Skip5EvenNumbersExample { 8 | public static void main(String[] args) { 9 | 10 | Stream evenNumbers = Stream.of(2, 4, 5, 8, 10, 12, 14, 16, 18, 20); 11 | 12 | List next20Numbers = evenNumbers 13 | .skip(5) 14 | .collect(Collectors.toList()); 15 | 16 | System.out.println("skipping first 5 even Numbers"); 17 | next20Numbers.forEach(number -> System.out.println(number)); 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/arrays/search/FIndValue.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.arrays.search; 2 | 3 | public class FIndValue { 4 | 5 | public static void main(String[] args) { 6 | 7 | int[] array = { 1, 4, 6, 2, 5 }; 8 | 9 | int findValueOf = 6; 10 | 11 | boolean isFound = false; 12 | for (int i = 0; i < array.length; i++) { 13 | 14 | if (array[i] == findValueOf) { 15 | isFound = true; 16 | break; 17 | } 18 | 19 | } 20 | 21 | if (isFound) { 22 | System.out.println("Number " + findValueOf + " is found in the array"); 23 | } else { 24 | System.out.println("Number " + findValueOf + " is not found in the array"); 25 | } 26 | } 27 | 28 | } 29 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/bytearray/Base64Encode.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.bytearray; 2 | 3 | import java.nio.charset.CharacterCodingException; 4 | import java.util.Base64; 5 | 6 | public class Base64Encode { 7 | 8 | public static void main(String[] args) throws CharacterCodingException { 9 | 10 | // creating byte array 11 | byte[] byteArray = { 76, 77, 65 }; 12 | 13 | // Create base simple decoder object 14 | Base64.Decoder simpleDecoder = Base64.getDecoder(); 15 | 16 | // Deconding the encoded string using decoder 17 | String decodedString = new String(simpleDecoder.decode(byteArray)); 18 | System.out.println("Decoded String : " + decodedString); 19 | 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/empty/ReturnEmptyArrayExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.empty; 2 | 3 | import org.apache.commons.lang3.ArrayUtils; 4 | 5 | public class ReturnEmptyArrayExample3 { 6 | 7 | public static void main(String[] args) { 8 | 9 | if (true) { 10 | int[] array1 = emptyArrayWIthCurlyBraces(); 11 | System.out.println("Length of int array 1 : " + array1.length); 12 | } 13 | 14 | if (100 > 0) { 15 | int[] array2 = emptyArrayWIthCurlyBraces(); 16 | System.out.println("Length of int array 2 : " + array2.length); 17 | } 18 | 19 | } 20 | 21 | public static int[] emptyArrayWIthCurlyBraces() { 22 | 23 | return ArrayUtils.EMPTY_INT_ARRAY; 24 | } 25 | } 26 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/files/readonlywrite/FileSetWritableExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.files.readonlywrite; 2 | 3 | import java.io.File; 4 | 5 | /** 6 | * Example to convert the file from read only to writable form. 7 | * 8 | * @author javaprogramto.com 9 | * 10 | */ 11 | public class FileSetWritableExample { 12 | 13 | public static void main(String[] args) { 14 | 15 | File newFile = new File("src/main/java/com/javaprogramto/files/readonlywrite/make-read-only.txt"); 16 | 17 | // Changing the file from read only to writable format. 18 | boolean isWritableNow = newFile.setWritable(true); 19 | 20 | System.out.println("Can write the file ? : " + isWritableNow); 21 | } 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/instant/InstantEpochSecondExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.instant; 2 | 3 | import java.time.Instant; 4 | 5 | public class InstantEpochSecondExample { 6 | public static void main(String[] args) { 7 | 8 | // Creating instant object from ofEpochMilli() 9 | Instant instantFromEpochSecond1 = Instant.ofEpochMilli(1606657474l); 10 | System.out.println("Instant 1 from Epoch Second value using ofEpochMilli() : " + instantFromEpochSecond1); 11 | 12 | Instant instantFromEpochSecond2 = Instant.ofEpochMilli(1667137474l); 13 | System.out.println("Instant 2 from Epoch Second value using ofEpochMilli() : " + instantFromEpochSecond2); 14 | } 15 | } 16 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/localdate/AddingDaysExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.localdate; 2 | 3 | import java.time.LocalDate; 4 | 5 | public class AddingDaysExample { 6 | 7 | public static void main(String[] args) { 8 | // creating current date time 9 | LocalDate currentDate = LocalDate.now(); 10 | 11 | // Getting the next date 12 | LocalDate nextDay = currentDate.plusDays(1); 13 | 14 | // Getting the previous date 15 | LocalDate previousDay = currentDate.minusDays(1); 16 | 17 | System.out.println("Current date : "+currentDate); 18 | System.out.println("Next date : "+nextDay); 19 | System.out.println("Previous date : "+previousDay); 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/optional/OptionalIsEmpty.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.optional; 2 | 3 | import java.util.Optional; 4 | 5 | public class OptionalIsEmpty { 6 | public static void main(String[] args) { 7 | 8 | // Creating optional 9 | Optional optional = Optional.ofNullable("javaprogramto.com"); 10 | 11 | System.out.println("Checking if optional has value with isEmpty() method"); 12 | //System.out.println("isEmpty value : " + optional.isEmpty()); 13 | 14 | // empty optional 15 | Optional emptyOptional = Optional.ofNullable(null); 16 | //System.out.println("isPreisEmptysent value for empty optional : " + emptyOptional.isEmpty()); 17 | 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/remove/character/StringRemoveCharacterExample4.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.remove.character; 2 | 3 | import java.util.stream.Collectors; 4 | 5 | public class StringRemoveCharacterExample4 { 6 | 7 | public static void main(String[] args) { 8 | 9 | String input = "hello +world ++"; 10 | char removalCh = '+'; 11 | 12 | String output = input.chars() 13 | .filter(ch -> ch != removalCh) 14 | .mapToObj(ch -> String.valueOf(ch)) 15 | .collect(Collectors.joining()); 16 | 17 | System.out.println("Input string 1 : " + input); 18 | System.out.println("Output string after removing the + symbol : " + output); 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/maths/LCMFromGCDExample.java: -------------------------------------------------------------------------------- 1 | 2 | package com.javaprogramto.programs.maths; 3 | 4 | public class LCMFromGCDExample { 5 | 6 | public static void main(String[] args) { 7 | 8 | printLCMUsingGCD(100, 152); 9 | printLCMUsingGCD(10, 1100); 10 | printLCMUsingGCD(140, 300); 11 | 12 | } 13 | 14 | private static void printLCMUsingGCD(int a, int b) { 15 | 16 | // finding GCD 17 | int gcd = 1; 18 | for (int i = 1; i <= a && i <= b; i++) { 19 | 20 | if(a % i == 0 && b % i == 0) { 21 | gcd = i; 22 | } 23 | } 24 | 25 | int lcm = a * b / gcd; 26 | System.out.printf("\nThe LCM of two numbers %d and %d is %d.", a, b, lcm); 27 | 28 | } 29 | 30 | } 31 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/w3schools/programs/string/StringSubStringExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.w3schools.programs.string; 2 | 3 | public class StringSubStringExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | String accountInfo = "In Active"; 8 | 9 | String accountStatus = accountInfo.substring(3); 10 | 11 | System.out.println("Extracted account status from account info text for account 1: "+accountStatus); 12 | 13 | accountInfo = "Is Locked"; 14 | 15 | accountStatus = accountInfo.substring(3); 16 | 17 | System.out.println("Extracted account status from account info text for account 2: "+accountStatus); 18 | 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /.settings/org.eclipse.wst.common.component: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/collections/set/add/LinkedHashSetAddExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.collections.set.add; 2 | 3 | import java.util.LinkedHashSet; 4 | import java.util.Set; 5 | 6 | public class LinkedHashSetAddExample { 7 | 8 | public static void main(String[] args) { 9 | 10 | Set set = new LinkedHashSet<>(); 11 | 12 | boolean isAdded = set.add(10); 13 | System.out.println("Is 10 added? " + isAdded); 14 | 15 | isAdded = set.add(10); 16 | System.out.println("Is 10 added again? " + isAdded); 17 | 18 | isAdded = set.add(20); 19 | isAdded = set.add(30); 20 | isAdded = set.add(40); 21 | 22 | System.out.println("LinkedHashSet values : " + set); 23 | 24 | } 25 | 26 | } 27 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/collections/treemap/comparator/TreeMapComparatorExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.collections.treemap.comparator; 2 | 3 | import java.util.Map; 4 | import java.util.TreeMap; 5 | 6 | public class TreeMapComparatorExample { 7 | 8 | public static void main(String[] args) { 9 | 10 | Map designationSalaryInUSD = new TreeMap<>(); 11 | 12 | designationSalaryInUSD.put("Software Engineer", 150_000); 13 | designationSalaryInUSD.put("Senior Software Engineer", 210_000); 14 | designationSalaryInUSD.put("Manger", 300_000); 15 | designationSalaryInUSD.put("Lead Engineer", 250_000); 16 | 17 | System.out.println("treemap - " + designationSalaryInUSD); 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/streams/reduce/StreamReduceExample7.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.streams.reduce; 2 | 3 | import java.util.Arrays; 4 | import java.util.List; 5 | 6 | import com.javaprogramto.java8.compare.Employee; 7 | 8 | public class StreamReduceExample7 { 9 | 10 | public static void main(String[] args) { 11 | 12 | List empList = Arrays.asList(new Employee(100, "A", 20), new Employee(200, "B", 30), 13 | new Employee(300, "C", 40)); 14 | 15 | Integer ageSum = empList.stream().map(emp -> emp.getAge()).reduce(new Employee(400, "new emp", 60).getAge(), 16 | (age1, age2) -> age1 + age2); 17 | 18 | System.out.println("age sum - " + ageSum); 19 | 20 | } 21 | 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/count/CountDigitsIterativeExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.count; 2 | 3 | public class CountDigitsIterativeExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | // Input number 8 | int number = 12345; 9 | 10 | // storing the original number in temp variable 11 | int originalNumber = number; 12 | 13 | // default digits count 14 | int countDigits = 0; 15 | 16 | // counting the digits 17 | while (number > 0) { 18 | 19 | number = number / 10; 20 | countDigits++; 21 | 22 | } 23 | 24 | // printing the output 25 | System.out.println("No of digits in number " + originalNumber + " is " + countDigits); 26 | 27 | } 28 | 29 | } 30 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java11/shebang/BatchJob.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java11.shebang; 2 | 3 | import java.util.Arrays; 4 | import java.util.stream.IntStream; 5 | import java.util.stream.Stream; 6 | 7 | public class BatchJob { 8 | 9 | public static void main(String[] args) { 10 | 11 | System.out.println("Hello World"); 12 | 13 | Stream stream = Arrays.stream(args); 14 | 15 | int sum = stream.mapToInt(Integer::parseInt).sum(); 16 | System.out.println("Total sum : "+sum); 17 | 18 | IntStream intStream =IntStream.range(1, 5); 19 | 20 | int output = intStream.sum(); 21 | System.out.println("Sum of first 5 numbers - "+output); 22 | } 23 | } 24 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/localdatetime/LocalDateTimeCreationExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.localdatetime; 2 | 3 | import java.time.LocalDateTime; 4 | 5 | public class LocalDateTimeCreationExample { 6 | 7 | public static void main(String[] args) { 8 | // Creating the current date and time using LocalDateTime.now() method 9 | LocalDateTime currentDatetime = LocalDateTime.now(); 10 | System.out.println("Current date time : "+currentDatetime); 11 | 12 | // Creating the future date and time using LocalDateTime.of() method 13 | LocalDateTime futureDateTime = LocalDateTime.of(2025, 01, 01, 00, 45); 14 | System.out.println("Future date time : "+futureDateTime); 15 | } 16 | 17 | } 18 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/maptolist/MapValuesToListExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.maptolist; 2 | 3 | import java.util.ArrayList; 4 | import java.util.HashMap; 5 | import java.util.List; 6 | import java.util.Map; 7 | 8 | public class MapValuesToListExample { 9 | 10 | public static void main(String[] args) { 11 | 12 | Map idNames = new HashMap<>(); 13 | 14 | idNames.put(100, "modi"); 15 | idNames.put(101, "trump"); 16 | idNames.put(102, "putin"); 17 | 18 | //converting all values from map to list. 19 | List ids =new ArrayList<>(idNames.values()); 20 | 21 | ids.forEach(id -> System.out.println(id)); 22 | } 23 | } 24 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/streams/infinite/StreamGenerateExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.streams.infinite; 2 | 3 | import java.util.List; 4 | import java.util.UUID; 5 | import java.util.function.Supplier; 6 | import java.util.stream.Collectors; 7 | import java.util.stream.Stream; 8 | 9 | public class StreamGenerateExample { 10 | 11 | public static void main(String[] args) { 12 | 13 | // Generates the UUID 14 | Supplier randomUUIDSupplier = () -> UUID.randomUUID(); 15 | 16 | List uuidList = Stream.generate(randomUUIDSupplier).limit(10).collect(Collectors.toList()); 17 | 18 | System.out.println("10 random UUID list : "+uuidList); 19 | 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/threads/AnonymousRunnableThread.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.threads; 2 | 3 | 4 | public class AnonymousRunnableThread { 5 | 6 | public static void main(String[] args) { 7 | 8 | new Thread(new Runnable() { 9 | @Override 10 | public void run() { 11 | 12 | for (int i = 0; i < 10; i++) { 13 | System.out.println(Thread.currentThread().getName()+", i value from thread- "+i); 14 | } 15 | } 16 | }).start(); 17 | 18 | for (int i = 0; i < 10; i++) { 19 | System.out.println(Thread.currentThread().getName()+", i value from main thread - "+i); 20 | } 21 | } 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/setall/DoubleArraySetAllExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.setall; 2 | 3 | import java.util.Arrays; 4 | 5 | public class DoubleArraySetAllExample { 6 | 7 | public static void main(String[] args) { 8 | 9 | // Creating a double array with default values 10 | double[] doubleArray = new double[7]; 11 | 12 | System.out.println("original double array with default values : "+ Arrays.toString(doubleArray)); 13 | 14 | // setting values to doubleArray using setAll() method 15 | Arrays.setAll(doubleArray, i -> i + 10.5); 16 | 17 | System.out.println("Double array.setAll(double) output: "+ Arrays.toString(doubleArray)); 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/setall/StringArraySetAllExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.setall; 2 | 3 | import java.util.Arrays; 4 | 5 | public class StringArraySetAllExample { 6 | 7 | public static void main(String[] args) { 8 | 9 | // Creating a String array with default values 10 | String[] stringArray = new String[7]; 11 | 12 | System.out.println("original long array with default values : "+ Arrays.toString(stringArray)); 13 | 14 | // setting values to stringArray using setAll() method 15 | Arrays.setAll(stringArray, i -> "Index " + i); 16 | 17 | System.out.println("String array.setAll(String) output: "+ Arrays.toString(stringArray)); 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/convert/string/toint/StringToIntException.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.convert.string.toint; 2 | 3 | /** 4 | * Example to exception in string to integer conversion 5 | * 6 | * @author Javaprogramto.com 7 | * 8 | */ 9 | public class StringToIntException { 10 | 11 | public static void main(String[] args) { 12 | 13 | // creating string with alphabets 14 | String s = "hello world"; 15 | 16 | // convert string to int using parseInt() method. This will throw exception 17 | // int number = Integer.parseInt(s); 18 | // int number = Integer.valueOf(s); 19 | Integer number = new Integer(s); 20 | 21 | // printing vlaues 22 | System.out.println("Number : " + number); 23 | } 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/design/patterns/strategy1/test/TestCalculationStrategy.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.design.patterns.strategy1.test; 2 | 3 | import com.javaprogramto.design.patterns.strategy1.algorithms.AdditionOperation; 4 | import com.javaprogramto.design.patterns.strategy1.context.OperationContext; 5 | 6 | public class TestCalculationStrategy { 7 | 8 | public static void main(String[] args) { 9 | 10 | OperationContext addContext = new OperationContext(new AdditionOperation()); 11 | int add = addContext.executeStrategy(10, 20); 12 | System.out.println("Addition Operation strategy output : "+add); 13 | 14 | // write there for the reamining three. 15 | 16 | 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/optional/OptionalGetExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.optional; 2 | 3 | import java.util.Optional; 4 | 5 | public class OptionalGetExample { 6 | 7 | public static void main(String[] args) { 8 | 9 | // Creating non null optional object. 10 | Optional optional= Optional.of("hello"); 11 | 12 | // checking value present in the optional or not. 13 | if(optional.isPresent()){ 14 | String value = optional.get(); 15 | System.out.println("Optional value : "+value); 16 | } else { 17 | // if optional has no value 18 | System.out.println("Optional has no value"); 19 | } 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/arrays/search/IntStreamFindValue.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.arrays.search; 2 | 3 | import java.util.stream.IntStream; 4 | 5 | public class IntStreamFindValue { 6 | 7 | public static void main(String[] args) { 8 | 9 | int[] array = { 10, 30, 20, 90, 40, 60 }; 10 | 11 | int findValueOf = 90; 12 | 13 | boolean isFound = false; 14 | 15 | isFound = IntStream.of(array).anyMatch(condition -> condition == findValueOf); 16 | 17 | if (isFound) { 18 | System.out.println("Number " + findValueOf + " is found in the array in java 8"); 19 | } else { 20 | System.out.println("Number " + findValueOf + " is not found in the array in java 8"); 21 | } 22 | } 23 | 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/numbers/NumberPowerMathPowExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.numbers; 2 | 3 | public class NumberPowerMathPowExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | // create two variables to store the base and exponenet values 8 | int base = 5; 9 | int exponent = 7; 10 | 11 | // printing the input values 12 | System.out.println("Base : " + base + ", Exponent : " + exponent); 13 | 14 | // a result variable to store the output 15 | double result = 1; 16 | 17 | // Calculating the power using Math.pow() method 18 | result = Math.pow(base, exponent); 19 | 20 | // Printing the output 21 | System.out.println("Result : " + result); 22 | } 23 | } 24 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/split/StringSplitExampleWithSlash.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings.split; 2 | 3 | public class StringSplitExampleWithSlash { 4 | 5 | public static void main(String[] args) { 6 | String fileLocation = "/Users/javaprogramto/Documents/course/blog/workspace/CoreJava/split.java"; 7 | 8 | String[] slashBasedSplitArray = fileLocation.split("/"); 9 | 10 | System.out.println("Splitting string with dot using regex 1"); 11 | for (String value : slashBasedSplitArray) { 12 | System.out.println(value); 13 | } 14 | 15 | System.out.println("No of folders in the path : " + (slashBasedSplitArray.length - 1)); 16 | 17 | 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/files/printwriter/tofile/PrintWriterToFileExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.files.printwriter.tofile; 2 | 3 | import java.io.File; 4 | import java.io.FileNotFoundException; 5 | import java.io.PrintWriter; 6 | 7 | public class PrintWriterToFileExample1 { 8 | 9 | public static void main(String[] args) throws FileNotFoundException { 10 | 11 | File file = new File("src/main/resources/print_writer/test2.txt"); 12 | 13 | PrintWriter writer = new PrintWriter(file); 14 | 15 | writer.println("Line 1"); 16 | writer.println("Line 2"); 17 | writer.println("Line 3"); 18 | 19 | writer.flush(); 20 | 21 | writer.close(); 22 | System.out.println("Done"); 23 | 24 | } 25 | 26 | } 27 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/localdate/LocalDateAtTimeExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.localdate; 2 | 3 | import java.time.LocalDate; 4 | import java.time.LocalDateTime; 5 | 6 | public class LocalDateAtTimeExample { 7 | 8 | public static void main(String[] args) { 9 | // localdate 10 | LocalDate localDate = LocalDate.now(); 11 | 12 | int hour = 10; 13 | int minute = 20; 14 | int second = 30; 15 | 16 | // setting time details and converting LocalDate to LocalDateTime. 17 | LocalDateTime dateAndTime = localDate.atTime(hour, minute, second); 18 | 19 | System.out.println("LocalDate : "+localDate); 20 | System.out.println("LocalDateTime : "+dateAndTime); 21 | 22 | } 23 | 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/characters/IfElseVowel.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.characters; 2 | 3 | public class IfElseVowel { 4 | 5 | public static void main(String[] args) { 6 | char ch = 'a'; 7 | 8 | if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u') { 9 | System.out.println("Chracter '" + ch + "' is a vowel"); 10 | } else { 11 | System.out.println("Chracter '" + ch + "' is a consonant"); 12 | } 13 | 14 | ch = 'b'; 15 | 16 | if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u') { 17 | System.out.println("Chracter '" + ch + "' is a vowel"); 18 | } else { 19 | System.out.println("Chracter '" + ch + "' is a consonant"); 20 | } 21 | 22 | } 23 | 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/remove/character/StringRemoveCharacterExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.remove.character; 2 | 3 | public class StringRemoveCharacterExample3 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String input = "hello +world ++"; 8 | char removalCh = '+'; 9 | 10 | char[] chars = input.toCharArray(); 11 | 12 | StringBuilder builder = new StringBuilder(); 13 | 14 | for (char ch : chars) { 15 | 16 | if (ch != removalCh) { 17 | builder.append(ch); 18 | } 19 | 20 | } 21 | 22 | System.out.println("Input string 1 : " + input); 23 | System.out.println("Output string after removing the + symbol : " + builder.toString()); 24 | } 25 | } 26 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/datatypes/diff/FloatVsDoubleDefault.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.datatypes.diff; 2 | 3 | public class FloatVsDoubleDefault { 4 | 5 | static float floatDefaultvalue; 6 | static double doubleDefaultvalue; 7 | 8 | public static void main(String[] args) { 9 | 10 | // default types 11 | double d = 12345.6789; // no error. so it is considered as double type. 12 | 13 | //float f = 12345.6789; // error. Type mismatch: cannot convert from double to float. float type is not 14 | // detected 15 | 16 | // default values 17 | 18 | System.out.println("Float type default value - " + floatDefaultvalue); 19 | System.out.println("Double type default value - " + doubleDefaultvalue); 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/files/printwriter/tofile/PrintWriterToFileExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.files.printwriter.tofile; 2 | 3 | import java.io.File; 4 | import java.io.FileNotFoundException; 5 | import java.io.PrintWriter; 6 | 7 | public class PrintWriterToFileExample2 { 8 | 9 | public static void main(String[] args) throws FileNotFoundException { 10 | 11 | File file = new File("src/main/resources/print_writer/file/test2.txt"); 12 | 13 | PrintWriter writer = new PrintWriter(file); 14 | 15 | writer.println("Line 1"); 16 | writer.println("Line 2"); 17 | writer.println("Line 3"); 18 | 19 | writer.flush(); 20 | 21 | writer.close(); 22 | System.out.println("Done"); 23 | 24 | } 25 | 26 | } 27 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/arraylist/ArrayListMaxSizeExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.arraylist; 2 | 3 | import java.util.ArrayList; 4 | import java.util.List; 5 | 6 | public class ArrayListMaxSizeExample2 { 7 | 8 | public static void main(String[] args) { 9 | 10 | System.out.println("Integer.MAX_VALUE - " + Integer.MAX_VALUE); 11 | System.out.println("Math.pow(2, 31) - " + (int) Math.pow(2, 31)); 12 | 13 | // default size is 10 14 | int maxValue = Integer.MAX_VALUE - 1; 15 | List intList = new ArrayList<>(maxValue); 16 | 17 | for (int i = 0; i < maxValue; i++) { 18 | intList.add(i); 19 | } 20 | 21 | System.out.println("Int list size - " + intList.size()); 22 | 23 | } 24 | 25 | } 26 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/datetimeformatter/DateTimeFormatterFormatStyleExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.datetimeformatter; 2 | 3 | import java.time.LocalDateTime; 4 | import java.time.format.DateTimeFormatter; 5 | import java.time.format.FormatStyle; 6 | 7 | public class DateTimeFormatterFormatStyleExample { 8 | 9 | public static void main(String[] args) { 10 | 11 | FormatStyle full = FormatStyle.FULL; 12 | 13 | DateTimeFormatter formatter = DateTimeFormatter.ofLocalizedDate(full); 14 | 15 | LocalDateTime datetime = LocalDateTime.now(); 16 | 17 | String fullForm = datetime.format(formatter); 18 | 19 | System.out.println("Full date form in string : "+fullForm); 20 | } 21 | 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/format/FormatTIme24HoursExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.format; 2 | 3 | import java.text.SimpleDateFormat; 4 | import java.util.Date; 5 | 6 | public class FormatTIme24HoursExample { 7 | 8 | public static void main(String[] args) { 9 | 10 | // Getting the current date and time 11 | Date currentDate = new Date(); 12 | 13 | // Creating simple date formatter to 24 hours 14 | SimpleDateFormat formatter = new SimpleDateFormat("kk:mm:ss"); 15 | 16 | // getting the time in 24 hours format 17 | String timeIn24Hours = formatter.format(currentDate); 18 | 19 | // printing the time 20 | System.out.println("Current time in 24 hours : "+timeIn24Hours); 21 | } 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/large/Largest3NumbersNestedIfExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.large; 2 | 3 | public class Largest3NumbersNestedIfExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | int number1 = 100; 8 | int number2 = 20; 9 | int number3 = 300; 10 | 11 | if (number1 >= number2) { 12 | if (number1 >= number3) { 13 | System.out.println(number1 + " is the biggest"); 14 | } else { 15 | System.out.println(number3 + " is the biggest"); 16 | } 17 | } else { 18 | if (number2 >= number3) { 19 | System.out.println(number2 + " is the biggest"); 20 | } else { 21 | System.out.println(number3 + " is the biggest"); 22 | } 23 | } 24 | 25 | } 26 | 27 | } 28 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/substring/count/SubstringCountExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.substring.count; 2 | 3 | public class SubstringCountExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | int count = countSubStringInString("222", "22"); 8 | System.out.println(count); 9 | 10 | count = countSubStringInString("madam", "ma"); 11 | System.out.println(count); 12 | 13 | } 14 | 15 | public static int countSubStringInString(String string, String toFind) { 16 | int position = 0; 17 | int count = 0; 18 | while ((position = string.indexOf(toFind, position)) != -1) { 19 | position = position + 1; 20 | count++; 21 | } 22 | return count; 23 | } 24 | 25 | } 26 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/numbers/swap/SwapNumbersWIthoutThirdVariable.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.numbers.swap; 2 | 3 | public class SwapNumbersWIthoutThirdVariable { 4 | 5 | public static void main(String[] args) { 6 | 7 | int firstNumber = 10; 8 | int secondNumber = 20; 9 | 10 | 11 | System.out.println("Before swapping two numbers : firstNumber " 12 | + firstNumber + ", secondNumber " + secondNumber); 13 | 14 | 15 | 16 | firstNumber = firstNumber + secondNumber; 17 | secondNumber = firstNumber - secondNumber; 18 | firstNumber = firstNumber - secondNumber; 19 | 20 | 21 | System.out.println("After swapping two numbers : firstNumber " 22 | + firstNumber + ", secondNumber " + secondNumber); 23 | } 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/convert/chartostring/CharToStringExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.convert.chartostring; 2 | 3 | /** 4 | * char to string using + operator 5 | * 6 | * @author javaprogramto.com 7 | * 8 | */ 9 | public class CharToStringExample3 { 10 | 11 | public static void main(String[] args) { 12 | 13 | char ch3 = 'x'; 14 | String returnedString = "" + ch3; 15 | System.out.println("Returned string 1 : " + returnedString); 16 | 17 | char ch1 = 'a'; 18 | String returnedString2 = "" + ch1; 19 | System.out.println("Returned string 2 : " + returnedString2); 20 | 21 | char ch2 = 'b'; 22 | String returnedString3 = "" + ch2; 23 | System.out.println("Returned string 3 : " + returnedString3); 24 | } 25 | } 26 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/conversions/string/StringtoStringArraySplitRegularExpression.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.conversions.string; 2 | 3 | public class StringtoStringArraySplitRegularExpression { 4 | 5 | public static void main(String[] args) { 6 | 7 | // input string 8 | String input = "hello geek"; 9 | 10 | // splitting string into string array using split() method with regular expression. 11 | String[] stringArray = input.split("(?!^)"); 12 | 13 | // printing the values of string array 14 | for (String string : stringArray) { 15 | System.out.println(string); 16 | } 17 | 18 | System.out.println(stringArray.length); 19 | System.out.println(input.length()); 20 | 21 | } 22 | 23 | } 24 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/sort/reverse/ArraySortReverseStrings.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.sort.reverse; 2 | 3 | import java.util.Arrays; 4 | import java.util.Collections; 5 | 6 | public class ArraySortReverseStrings { 7 | 8 | public static void main(String[] args) { 9 | 10 | String[] stringArray = new String[5]; 11 | stringArray[0] = "G"; 12 | stringArray[1] = "Z"; 13 | stringArray[2] = "A"; 14 | stringArray[3] = "N"; 15 | stringArray[4] = "I"; 16 | 17 | System.out.println("String array before sort - " + Arrays.toString(stringArray)); 18 | Arrays.sort(stringArray, Collections.reverseOrder()); 19 | 20 | System.out.println("String array after sort - " + Arrays.toString(stringArray)); 21 | 22 | } 23 | 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/collectors/tolist/StreamCollectToListExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.collectors.tolist; 2 | 3 | import java.util.LinkedList; 4 | import java.util.List; 5 | import java.util.stream.Collectors; 6 | import java.util.stream.Stream; 7 | 8 | public class StreamCollectToListExample2 { 9 | 10 | public static void main(String[] args) { 11 | Stream vowels2 = Stream.of("A", "E", "I", "O", "U"); 12 | 13 | List list = vowels2.collect(Collectors.toCollection(LinkedList::new)); 14 | 15 | if(list instanceof LinkedList) { 16 | System.out.println("Returned list is a instacne of LinkedList"); 17 | } 18 | System.out.println("stream collect to LinkedList output : " + list); 19 | 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/iterate/SplitIteratorForEachRemainingExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.iterate; 2 | 3 | import java.util.HashSet; 4 | import java.util.Set; 5 | import java.util.Spliterator; 6 | import java.util.function.Consumer; 7 | 8 | public class SplitIteratorForEachRemainingExample { 9 | 10 | public static void main(String[] args) { 11 | 12 | Set values = new HashSet<>(); 13 | 14 | values.add(100); 15 | values.add(200); 16 | values.add(300); 17 | values.add(400); 18 | 19 | Spliterator splitIterator = values.stream().spliterator(); 20 | 21 | Consumer consumer = (number) -> System.out.println(number - 1); 22 | 23 | splitIterator.forEachRemaining(consumer); 24 | } 25 | } 26 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/permutations/StringPermutationsExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.permutations; 2 | 3 | import java.util.stream.IntStream; 4 | 5 | public class StringPermutationsExample2 { 6 | 7 | public static void main(String[] args) { 8 | 9 | stringPermuteAndPrint("", "ABC"); 10 | 11 | } 12 | 13 | // java 8 stream example 14 | private static void stringPermuteAndPrint(String prefix, String str) { 15 | int n = str.length(); 16 | if (n == 0) { 17 | System.out.print(prefix + " "); 18 | } else { 19 | IntStream.range(0, n).parallel().forEach( 20 | i -> stringPermuteAndPrint(prefix + str.charAt(i), str.substring(i + 1, n) + str.substring(0, i))); 21 | } 22 | } 23 | 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/w3schools/programs/string/StringSubEndIndexStringExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.w3schools.programs.string; 2 | 3 | public class StringSubEndIndexStringExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | String accountInfo = "Is Active my account?"; 8 | 9 | String accountStatus = accountInfo.substring(3, 10); 10 | 11 | System.out.println("Extracted account status from account info text for account 1: "+accountStatus); 12 | 13 | accountInfo = "is my Locked ?"; 14 | 15 | accountStatus = accountInfo.substring(6, 12); 16 | 17 | System.out.println("Extracted account status from account info text for account 2: "+accountStatus); 18 | 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/keywords/extend/FinalClasesExtendsExamples.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.keywords.extend; 2 | 3 | import java.util.Calendar; 4 | 5 | public class FinalClasesExtendsExamples { 6 | 7 | public static void main(String[] args) { 8 | 9 | } 10 | } 11 | 12 | final class Calculator { 13 | 14 | public int sum(int a, int b) { 15 | return a + b; 16 | } 17 | 18 | public int substract(int a, int b) { 19 | return a - b; 20 | } 21 | 22 | public int multiply(int a, int b) { 23 | return a * b; 24 | } 25 | 26 | public int divide(int a, int b) { 27 | return a / b; 28 | } 29 | 30 | public int reminder(int a, int b) { 31 | return a % b; 32 | } 33 | 34 | } 35 | 36 | class MyCalculator extends Calendar{ 37 | 38 | 39 | } -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/joining/JoiningStringDelimiterExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.joining; 2 | 3 | public class JoiningStringDelimiterExample3 { 4 | 5 | public static void main(String[] args) { 6 | 7 | // input 1 8 | String output1 = stringJoinWithDelimiter("-", "hello", "world", "welcome", "to", "java", "programs"); 9 | System.out.println("Ouptut 1 : " + output1); 10 | 11 | // input 1 12 | String output2 = stringJoinWithDelimiter("**", "this", "is", "second", "input"); 13 | System.out.println("Ouptut 2 : " + output2); 14 | 15 | } 16 | 17 | private static String stringJoinWithDelimiter(String delimiter, String... strings) { 18 | 19 | return String.join(delimiter, strings); 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/tolong/StringToLongExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.tolong; 2 | 3 | public class StringToLongExample3 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String positiveString = "12345"; 8 | 9 | Long longvalue1 = new Long(positiveString); 10 | System.out.println("Positive Long value 1 : " + longvalue1); 11 | 12 | String positiveString2 = "+12345"; 13 | 14 | Long longvalue2 = new Long(positiveString2); 15 | System.out.println("Positive Long value 2 : " + longvalue2); 16 | 17 | String negativeValue1 = "-12345"; 18 | 19 | Long longvalue3 = new Long(negativeValue1); 20 | System.out.println("Negative Long value 3 : " + longvalue3); 21 | 22 | } 23 | 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/split/StringSplitLimitExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings.split; 2 | 3 | public class StringSplitLimitExample3 { 4 | 5 | public static void main(String[] args) { 6 | String stringWithEndingWithDelimiter = "Java:Program:::to:.com:::"; 7 | 8 | String[] arrayWithoutLimitValue = stringWithEndingWithDelimiter.split(":"); 9 | 10 | String[] arrayWithLimitValue = stringWithEndingWithDelimiter.split(":", -2); 11 | 12 | System.out.println("returned array size with limit parameter : "+arrayWithLimitValue.length); 13 | for(String value : arrayWithLimitValue){ 14 | System.out.println(value); 15 | } 16 | System.out.println("Done"); 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/threads/AnonymousThreadExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.threads; 2 | 3 | public class AnonymousThreadExample { 4 | public static void main(String[] args) { 5 | new Thread() { 6 | 7 | public void run() { 8 | 9 | for (int i = 0; i <= 10; i++) { 10 | System.out.println( 11 | "Executing " + i + " thread name - " + Thread.currentThread().getName()); 12 | } 13 | 14 | } 15 | 16 | }.start(); 17 | 18 | for (int i = 0; i <= 10; i++) { 19 | System.out.println( 20 | "Executing " + i + " thread name - " + Thread.currentThread().getName()); 21 | } 22 | } 23 | } 24 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/chars/AddCharToStringExample4.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.chars; 2 | 3 | public class AddCharToStringExample4 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String longString = "very difficult to beat 90% in engineering"; 8 | 9 | String addMiddle = longString.substring(0, longString.length() / 2) + ',' 10 | + longString.substring(longString.length() / 2); 11 | 12 | System.out.println("after adding in middle : " + addMiddle); 13 | 14 | String atStartOfString = 'A' + longString.substring(0); 15 | String atEndOfString = longString.substring(0) + 'A'; 16 | 17 | System.out.println("At start of string : "+atStartOfString); 18 | System.out.println("At end of string : "+atEndOfString); 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/streams/filter/ThrowingFunctionExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.streams.filter; 2 | 3 | import java.util.Arrays; 4 | import java.util.List; 5 | import java.util.stream.Stream; 6 | 7 | import pl.touk.throwing.ThrowingFunction; 8 | 9 | public class ThrowingFunctionExample { 10 | 11 | public static void main(String[] args) { 12 | Book b1 = new Book(123, "/bookstore/100/23/book123.pdf"); 13 | Book b2 = new Book(145, "/bookstore/100/45/book145.pdf"); 14 | Book b3 = new Book(167, "/bookstore/100/67/book167.pdf"); 15 | 16 | List books = Arrays.asList(b1, b2, b3); 17 | 18 | Stream validBooks = books.stream().map(ThrowingFunction.unchecked(Book::isValidBookLocation)); 19 | 20 | } 21 | 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/streams/find/FindAnyExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.streams.find; 2 | 3 | import java.util.Arrays; 4 | import java.util.List; 5 | import java.util.Optional; 6 | 7 | public class FindAnyExample { 8 | 9 | public static void main(String[] args) { 10 | 11 | // creating a list with string values 12 | List values = Arrays.asList("A", "B", "C", "F", "D"); 13 | 14 | // getting the any value from stream. 15 | Optional anyValue = values.stream().findAny(); 16 | 17 | // printing the value 18 | if (anyValue.isPresent()) { 19 | System.out.println("Any value from stream : " + anyValue.get()); 20 | } else { 21 | System.out.println("No value presnt in the stream."); 22 | } 23 | } 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/MultiplicationTableForLoop.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs; 2 | 3 | public class MultiplicationTableForLoop { 4 | 5 | public static void main(String[] args) { 6 | int tableNumber = 10; 7 | 8 | System.out.println("Generating the table 10"); 9 | // generating table 10 10 | for (int i = 1; i <= 10; i++) { 11 | 12 | System.out.format("%d * %d = %d \n", tableNumber, i, tableNumber * i); 13 | 14 | } 15 | 16 | // generating the 20 table. 17 | System.out.println("\nGenerating the table 20"); 18 | int anotherTableNumber = 20; 19 | for (int i = 1; i <= 10; i++) { 20 | 21 | System.out.format("%d * %d = %d \n", anotherTableNumber, i, anotherTableNumber * i); 22 | 23 | } 24 | 25 | } 26 | 27 | } 28 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/datatypes/diff/FloatVsDoublePrecision.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.datatypes.diff; 2 | 3 | public class FloatVsDoublePrecision { 4 | 5 | public static void main(String[] args) { 6 | 7 | // double examples 8 | double d = 1.2345678912345678; 9 | 10 | System.out.println("Double type precision value 1 - " + d); 11 | 12 | double d2 = 1.1020304050d; 13 | System.out.println("Double type precision value 2 with suffix d - " + d2); 14 | 15 | // float examples 16 | 17 | float f = 1.23456789123456789f; 18 | 19 | System.out.println("\n" + "Float type precision value 1 - " + f); 20 | 21 | float f2 = (float) 2.10203040; 22 | System.out.println("Float type precision value 2 with suffix d - " + f2); 23 | 24 | } 25 | 26 | } 27 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/files/printwriter/tofile/PrintWriterToFileExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.files.printwriter.tofile; 2 | 3 | import java.io.File; 4 | import java.io.FileNotFoundException; 5 | import java.io.PrintWriter; 6 | 7 | public class PrintWriterToFileExample3 { 8 | 9 | public static void main(String[] args) throws FileNotFoundException { 10 | 11 | File file = new File("src/main/resources/print_writer/file/test2.txt"); 12 | file.getParentFile().mkdirs(); 13 | 14 | PrintWriter writer = new PrintWriter(file); 15 | 16 | writer.println("Line 1"); 17 | writer.println("Line 2"); 18 | writer.println("Line 3"); 19 | 20 | writer.flush(); 21 | 22 | writer.close(); 23 | System.out.println("Done"); 24 | 25 | } 26 | } 27 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/remove/duplicates/StringRemoveDuplicatesExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.remove.duplicates; 2 | 3 | import java.util.Arrays; 4 | import java.util.HashSet; 5 | import java.util.Set; 6 | import java.util.stream.Collectors; 7 | 8 | public class StringRemoveDuplicatesExample3 { 9 | 10 | public static void main(String[] args) { 11 | 12 | String orignalString = "world world"; 13 | 14 | String output = Arrays.asList(orignalString.split("")) 15 | .stream() 16 | .distinct() 17 | .collect(Collectors.joining()); 18 | 19 | System.out.println("Original String : " + orignalString); 20 | System.out.println("After removing the duplicates : " + output); 21 | 22 | } 23 | 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/tolong/StringToLongExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.tolong; 2 | 3 | public class StringToLongExample2 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String positiveString = "12345"; 8 | 9 | Long longvalue1 = Long.valueOf(positiveString); 10 | System.out.println("Positive Long value 1 : " + longvalue1); 11 | 12 | String positiveString2 = "+12345"; 13 | 14 | Long longvalue2 = Long.valueOf(positiveString2); 15 | System.out.println("Positive Long value 2 : " + longvalue2); 16 | 17 | String negativeValue1 = "-12345"; 18 | 19 | Long longvalue3 = Long.valueOf(negativeValue1); 20 | System.out.println("Negative Long value 3 : " + longvalue3); 21 | 22 | } 23 | 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/threads/delay/DelayWithExecutorService.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.threads.delay; 2 | 3 | import java.util.concurrent.Executors; 4 | import java.util.concurrent.ScheduledExecutorService; 5 | import java.util.concurrent.TimeUnit; 6 | 7 | public class DelayWithExecutorService { 8 | 9 | public static void main(String[] args) { 10 | 11 | ScheduledExecutorService executorService = Executors.newSingleThreadScheduledExecutor(); 12 | 13 | executorService.schedule(new NewTask2(), 1000, TimeUnit.MILLISECONDS); 14 | 15 | } 16 | 17 | } 18 | 19 | class NewTask implements Runnable { 20 | 21 | @Override 22 | public void run() { 23 | 24 | System.out.println("Task completed"); 25 | } 26 | 27 | } 28 | 29 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/threads/delay/DelayWithThreadSleep.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.threads.delay; 2 | 3 | public class DelayWithThreadSleep { 4 | 5 | public static void main(String[] args) { 6 | 7 | System.out.println("Program Started..."); 8 | System.out.println("Current Thread name : " + Thread.currentThread().getName()); 9 | 10 | // do some task 11 | 12 | try { 13 | System.out.println("Sleepin for 5 seconds"); 14 | Thread.sleep(5000); 15 | } catch (InterruptedException e) { 16 | System.out.println("Thread is interrupted"); 17 | } 18 | System.out.println("Code delay completed."); 19 | 20 | System.out.println("Program Ended"); 21 | 22 | } 23 | 24 | } -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/functional/interfaces/function/java8FunctionExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.functional.interfaces.function; 2 | 3 | import java.util.function.Function; 4 | 5 | public class java8FunctionExample { 6 | 7 | public static void main(String[] args) { 8 | 9 | Function function = str -> str.length(); 10 | 11 | int length = function.apply("Hello world"); 12 | System.out.println("Fucntion to find string length :" + length); 13 | 14 | Function function2 = number -> String.valueOf(number) + " is now String"; 15 | 16 | String output = function2.apply(1260); 17 | System.out.println("Funtion to covnert Integer to String : "+output); 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/numbers/NumberPowerForLoopExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.numbers; 2 | 3 | public class NumberPowerForLoopExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | // create two variables to store the base and exponenet values 8 | int base = 4; 9 | int exponent = 3; 10 | 11 | // printing the input values 12 | System.out.println("Base : " + base + ", Exponent : " + exponent); 13 | 14 | // a result variable to store the output 15 | int result = 1; 16 | 17 | // Calculating the power using for loop 18 | for (int i = 1; i <= exponent; i++) { 19 | result = result * base; 20 | } 21 | 22 | // Printing the output 23 | System.out.println("Result : " + result); 24 | 25 | } 26 | 27 | } 28 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/palindrome/StringCheckPalindrome3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.palindrome; 2 | 3 | public class StringCheckPalindrome3 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String input1 = "hello"; 8 | boolean isPalindrome = isPalindromeWithStringBuilder(input1); 9 | System.out.println("Is " + input1 + " palindrome? " + isPalindrome); 10 | 11 | String input2 = "abcba"; 12 | isPalindrome = isPalindromeWithStringBuilder(input2); 13 | System.out.println("Is " + input2 + " palindrome? " + isPalindrome); 14 | } 15 | 16 | private static boolean isPalindromeWithStringBuilder(String input) { 17 | 18 | return input.equals(new StringBuilder(input).reverse().toString()); 19 | } 20 | 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/remove/duplicates/StringRemoveDuplicatesExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.remove.duplicates; 2 | 3 | public class StringRemoveDuplicatesExample1 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String orignalString = "world world"; 8 | 9 | StringBuilder builder = new StringBuilder(); 10 | 11 | for (int i = 0; i < orignalString.length(); i++) { 12 | 13 | if (builder.indexOf(String.valueOf(orignalString.charAt(i))) == -1) { 14 | 15 | builder.append(orignalString.charAt(i)); 16 | 17 | } 18 | } 19 | 20 | System.out.println("Original String : " + orignalString); 21 | System.out.println("After removing the duplicates : " + builder.toString()); 22 | 23 | } 24 | 25 | } 26 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/tolong/StringToLongExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.tolong; 2 | 3 | public class StringToLongExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | String positiveString = "12345"; 8 | 9 | long longvalue1 = Long.parseLong(positiveString); 10 | System.out.println("Positive Long value 1 : " + longvalue1); 11 | 12 | String positiveString2 = "+12345"; 13 | 14 | long longvalue2 = Long.parseLong(positiveString2); 15 | System.out.println("Positive Long value 2 : " + longvalue2); 16 | 17 | String negativeValue1 = "-12345"; 18 | 19 | long longvalue3 = Long.parseLong(negativeValue1); 20 | System.out.println("Negative Long value 3 : " + longvalue3); 21 | 22 | } 23 | 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/add/JavaArrayToAddExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.add; 2 | 3 | import java.util.ArrayList; 4 | import java.util.Arrays; 5 | import java.util.List; 6 | 7 | public class JavaArrayToAddExample2 { 8 | 9 | public static void main(String[] args) { 10 | 11 | Integer[] array = { 10, 20, 30, 40, 30, 40 }; 12 | 13 | System.out.println("Initial array values " + Arrays.toString(array)); 14 | 15 | List integers = new ArrayList<>(); 16 | 17 | for (int a : array) { 18 | integers.add(a); 19 | } 20 | 21 | int newValue = 50; 22 | 23 | integers.add(newValue); 24 | 25 | array = integers.toArray(array); 26 | 27 | System.out.println("Array after adding 50 value " + Arrays.toString(array)); 28 | 29 | } 30 | } 31 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/concat/StreamConcatException.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.concat; 2 | 3 | 4 | import java.util.stream.Stream; 5 | 6 | public class StreamConcatException { 7 | 8 | public static void main(String[] args) { 9 | 10 | // Creating stream 1 11 | Stream stream1 = Stream.of(1, 1, 1); 12 | 13 | // Creating stream 2 14 | Stream stream2 = Stream.of(2, 2, 2); 15 | 16 | // Merging two streams in java 8 using concat() method 17 | Stream resultStream = Stream.concat(stream1, stream2); 18 | 19 | // printing stream1 values 20 | System.out.println("Stream 1 values are "); 21 | stream1.forEach(even -> System.out.println(even)); 22 | } 23 | 24 | } -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/arrays/search/IntStreamFindStringValue.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.arrays.search; 2 | 3 | import java.util.Arrays; 4 | 5 | public class IntStreamFindStringValue { 6 | 7 | public static void main(String[] args) { 8 | 9 | String[] stringArray = new String[] { "hello", "how", "life", "is", "going" }; 10 | 11 | String findString = "java"; 12 | 13 | boolean isFound = false; 14 | 15 | isFound = Arrays.stream(stringArray).anyMatch(value -> value.equals(findString)); 16 | 17 | if (isFound) { 18 | System.out.println("String " + findString + " is found in the array in java 8"); 19 | } else { 20 | System.out.println("String " + findString + " is not found in the array in java 8"); 21 | } 22 | } 23 | 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/numbers/math/MathAbsoluteExample4.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.numbers.math; 2 | 3 | public class MathAbsoluteExample4 { 4 | 5 | public static void main(String[] args) { 6 | 7 | // for Wrapper Long values 8 | Long longValue = -100l; 9 | Long absValueofLong = Math.abs(longValue); 10 | 11 | System.out.println("Long - abs value of " + longValue + " is " + absValueofLong); 12 | 13 | longValue = 200l; 14 | absValueofLong = Math.abs(longValue); 15 | 16 | System.out.println("Long - abs value of " + longValue + " is " + absValueofLong); 17 | 18 | longValue = -0l; 19 | absValueofLong = Math.abs(longValue); 20 | 21 | System.out.println("Long - abs value of " + longValue + " is " + absValueofLong); 22 | } 23 | } 24 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/todouble/decimal/StringToDoubleDecimalsPlaces2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.todouble.decimal; 2 | 3 | public class StringToDoubleDecimalsPlaces2 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String decimalValueInString = "9.144678376262"; 8 | 9 | // convert string to double 10 | 11 | double doubleDecimalValue = Double.parseDouble(decimalValueInString); 12 | 13 | System.out.println("Double in string : "+decimalValueInString); 14 | System.out.println("Double value : "+doubleDecimalValue); 15 | 16 | String strDoubleDecimals = String.format("%.2f", doubleDecimalValue); 17 | 18 | System.out.println("Double with 2 decimal values : "+strDoubleDecimals); 19 | 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/StringStartsWithIndexExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings; 2 | 3 | public class StringStartsWithIndexExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | String s1 = "hello world"; 8 | 9 | boolean isStringStartsWithHello = s1.startsWith("hello", 5); 10 | 11 | System.out.println("String starts with hello or not : "+isStringStartsWithHello); 12 | System.out.println("Phone number starts with +91 "+"+91 12345678".startsWith("+678", 2)); 13 | 14 | System.out.println("javaprogramto.com starts with java : "+"javaprogramto.com".startsWith("program",4)); 15 | 16 | System.out.println("starts with index : "+"phone: +91 123456789".startsWith("+91", 7)); 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/threads/AnonymousRunnableExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.threads; 2 | 3 | public class AnonymousRunnableExample { 4 | public static void main(String[] args) { 5 | new Thread(new Runnable() { 6 | @Override 7 | public void run() { 8 | for (int i = 0; i <= 10; i++) { 9 | System.out.println( 10 | "Executing " + i + " thread name - " + Thread.currentThread().getName()); 11 | } 12 | } 13 | }).start(); 14 | 15 | for (int i = 0; i <= 10; i++) { 16 | System.out.println( 17 | "Executing " + i + " thread name - " + Thread.currentThread().getName()); 18 | } 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/escape/sequences/EscapeSequencesExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.escape.sequences; 2 | 3 | public class EscapeSequencesExample1 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String newLineEscapeSequence1 = "\n"; 8 | System.out.println("\\n length is "+newLineEscapeSequence1.length()); 9 | 10 | 11 | String newLineEscapeSequence2 = "\n\n"; 12 | System.out.println("\\n\\n length is "+newLineEscapeSequence2.length()); 13 | 14 | 15 | String tabEscapeSequence1 = "\t"; 16 | System.out.println("\\t length is "+tabEscapeSequence1.length()); 17 | 18 | 19 | String backslashEscapeSequence1 = "\\"; 20 | System.out.println("\\\\ length is "+backslashEscapeSequence1.length()); 21 | 22 | } 23 | } 24 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/numbers/NumberPowerWhileLoopExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.numbers; 2 | 3 | public class NumberPowerWhileLoopExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | // create two variables to store the base and exponenet values 8 | int base = 5; 9 | int exponent = 4; 10 | 11 | // printing the input values 12 | System.out.println("Base : " + base + ", Exponent : " + exponent); 13 | 14 | // a result variable to store the output 15 | int result = 1; 16 | 17 | // Calculating the power using while loop 18 | while (exponent > 0) { 19 | result = result * base; 20 | exponent--; 21 | } 22 | 23 | // Printing the output 24 | System.out.println("Result : " + result); 25 | 26 | } 27 | 28 | } 29 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/substring/StringContainsSubstringExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.substrin; 2 | 3 | public class StringContainsSubstringExample2 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String input = "hello world - welcome"; 8 | String substring = "world"; 9 | int index = input.indexOf(substring); 10 | 11 | System.out.println(index); 12 | 13 | substring = "llo"; 14 | index = input.lastIndexOf(substring); 15 | 16 | System.out.println(index); 17 | 18 | substring = "java"; 19 | index = input.indexOf(substring); 20 | 21 | System.out.println(index); 22 | 23 | substring = "Hello"; 24 | index = input.lastIndexOf(substring); 25 | 26 | System.out.println(index); 27 | 28 | } 29 | } 30 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/tofloat/StringToFloatExample1.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.tofloat; 2 | 3 | public class StringToFloatExample1 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String floatValueInString1 = "-789.123F"; 8 | 9 | float floatValue1 = Float.parseFloat(floatValueInString1); 10 | 11 | System.out.println("Float value in String : " + floatValueInString1); 12 | System.out.println("String to Float value : " + floatValue1); 13 | 14 | String floatValueInString2 = "123.45"; 15 | 16 | float floatValue2 = Float.parseFloat(floatValueInString2); 17 | 18 | System.out.println("Float value in String : " + floatValueInString2); 19 | System.out.println("String to Float value : " + floatValue2); 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/StringHashcodeCheckExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings; 2 | 3 | public class StringHashcodeCheckExample { 4 | 5 | public static void main(String[] args) { 6 | 7 | String str1 = "FB"; 8 | 9 | int hashCode1 = str1.hashCode(); 10 | 11 | System.out.println("hash code of str 1 : " + hashCode1); 12 | 13 | String str2 = "FB"; 14 | 15 | int hashCode2 = str2.hashCode(); 16 | 17 | System.out.println("hash code of str 2 : " + hashCode2); 18 | 19 | if(hashCode1 == hashCode2){ 20 | System.out.println("Hashcodes of str1 and str2 are same"); 21 | } else{ 22 | System.out.println("str1 and str2 hashcodes are not same"); 23 | } 24 | } 25 | } 26 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/strings/mix/StringsConcatenateExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.strings.mix; 2 | 3 | public class StringsConcatenateExample3 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String s1 = new String("JavaProgramTo.com"); 8 | String s2 = "welcome, Java developer"; 9 | 10 | StringBuffer buffer = new StringBuffer(); 11 | buffer.append(s1); 12 | buffer.append(s2); 13 | String s3 = buffer.toString(); 14 | 15 | System.out.println("Mixed string 1 using StringBuffer : " + s3); 16 | 17 | StringBuilder builder = new StringBuilder(); 18 | builder.append("this is a "); 19 | builder.append("new string"); 20 | String s4 = builder.toString(); 21 | 22 | System.out.println("Mixed string 2 using StringBuilder : " + s4); 23 | } 24 | } -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/datetimeformatter/DateTimeFormatterFormatStyleExample23.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.datetimeformatter; 2 | 3 | import java.time.LocalDateTime; 4 | import java.time.format.DateTimeFormatter; 5 | import java.time.format.FormatStyle; 6 | 7 | public class DateTimeFormatterFormatStyleExample23{ 8 | 9 | //DateTimeFormatterFormatStyleExample23.java 10 | public static void main(String[] args) { 11 | 12 | FormatStyle full = FormatStyle.FULL; 13 | 14 | DateTimeFormatter formatter = DateTimeFormatter.ofLocalizedDate(full); 15 | 16 | LocalDateTime datetime = LocalDateTime.now(); 17 | 18 | String fullForm = datetime.format(formatter); 19 | 20 | System.out.println("Full date form in string : " + fullForm); 21 | } 22 | 23 | } 24 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/zoneddatetime/GetTimezoneExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.zoneddatetime; 2 | 3 | import java.time.ZoneId; 4 | import java.time.ZonedDateTime; 5 | 6 | public class GetTimezoneExample { 7 | 8 | public static void main(String[] args) { 9 | // Create object using of() method 10 | ZonedDateTime zonedtime = ZonedDateTime.of(2023, 01, 01, 01, 01, 30, 1000, ZoneId.of("America/Chicago")); 11 | 12 | // Getting timezone in string 13 | ZoneId currentZoneId = zonedtime.getZone(); 14 | 15 | // print the value onto console 16 | System.out.println("Get timezone : " + currentZoneId.getId()); 17 | 18 | // printing the offset value 19 | System.out.println("Timezone offset value : " + currentZoneId.getRules()); 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/bytearray/CharsetDecode.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.bytearray; 2 | 3 | import java.nio.ByteBuffer; 4 | import java.nio.charset.Charset; 5 | import java.nio.charset.StandardCharsets; 6 | 7 | public class CharsetDecode { 8 | 9 | public static void main(String[] args) { 10 | 11 | // creating byte array 12 | byte[] byteArray = { 106, 97, 118, 97, 112, 114, 111, 103, 114, 109, 116, 111, 46, 99, 111, 109, 32, 63, 63, 63, 13 | 63 }; 14 | // create charset object 15 | Charset charset = StandardCharsets.US_ASCII; 16 | 17 | ByteBuffer byteBuffer = ByteBuffer.wrap(byteArray); 18 | // decoding string 19 | String output = charset.decode(byteBuffer).toString(); 20 | 21 | System.out.println("output : " + output); 22 | 23 | } 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/multidimensional/NestedArraysExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.multidimensional; 2 | 3 | import java.util.Arrays; 4 | import java.util.Collections; 5 | 6 | public class NestedArraysExample2 { 7 | 8 | public static void main(String[] args) { 9 | 10 | int[] array1 = { 0, 0 }; 11 | 12 | int[] array2 = new int[5]; 13 | 14 | int[] array3 = new int[5]; 15 | Arrays.fill(array3, 5); 16 | 17 | Integer[] array4 = Collections.nCopies(array3.length, 0).toArray(new Integer[0]); 18 | 19 | System.out.println("array1[0] value " + array1[0]); 20 | System.out.println("array2[0] value " + array2[0]); 21 | System.out.println("array3[0] value " + array3[0]); 22 | System.out.println("array4[0] value " + array4[0]); 23 | 24 | } 25 | 26 | } 27 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/dates/currentdate/CurrentTimeStamp.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.dates.currentdate; 2 | 3 | import java.time.Instant; 4 | 5 | public class CurrentTimeStamp { 6 | 7 | public static void main(String[] args) { 8 | 9 | // getting the current timestamp from Instant.now() method 10 | Instant currentInstant = Instant.now(); 11 | 12 | // getting the current time in milliseoconds from Instant 13 | long timeInMillis = currentInstant.toEpochMilli(); 14 | 15 | System.out.println("Current timestamp in milli seconds "+timeInMillis); 16 | 17 | // Getting the current instant in seconds 18 | long timeInSeconds = currentInstant.getEpochSecond(); 19 | 20 | System.out.println("Current timestamp in seconds : "+timeInSeconds); 21 | } 22 | } 23 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/java8/streams/find/FindAnyParallelStreamExample.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.java8.streams.find; 2 | 3 | import java.util.Arrays; 4 | import java.util.List; 5 | import java.util.Optional; 6 | 7 | public class FindAnyParallelStreamExample { 8 | 9 | public static void main(String[] args) { 10 | 11 | // creating a list with string values 12 | List values = Arrays.asList("A", "B", "C", "F", "D"); 13 | 14 | // Creating parallel stream. 15 | Optional anyValue = values.stream().parallel().findAny(); 16 | 17 | // printing the value 18 | if (anyValue.isPresent()) { 19 | System.out.println("Any value from stream : " + anyValue.get()); 20 | } else { 21 | System.out.println("No value presnt in the stream."); 22 | } 23 | } 24 | } 25 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/numbers/math/MathAbsoluteExample3.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.numbers.math; 2 | 3 | public class MathAbsoluteExample3 { 4 | 5 | public static void main(String[] args) { 6 | 7 | // for Wrapper Integer values 8 | Integer integer = -100; 9 | Integer absValueofInteger = Math.abs(integer); 10 | 11 | System.out.println("Integer - abs value of " + integer + " is " + absValueofInteger); 12 | 13 | integer = 200; 14 | absValueofInteger = Math.abs(integer); 15 | 16 | System.out.println("Integer - abs value of " + integer + " is " + absValueofInteger); 17 | 18 | integer = -0; 19 | absValueofInteger = Math.abs(integer); 20 | 21 | System.out.println("Integer - abs value of " + integer + " is " + absValueofInteger); 22 | } 23 | } 24 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/programs/strings/tofloat/StringToFloatExample2.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.programs.strings.tofloat; 2 | 3 | public class StringToFloatExample2 { 4 | 5 | public static void main(String[] args) { 6 | 7 | String floatValueInString1 = "789.123F"; 8 | 9 | Float floatValue1 = Float.valueOf(floatValueInString1); 10 | 11 | System.out.println("Float value in String : " + floatValueInString1); 12 | System.out.println("String to Wrapper Float value : " + floatValue1); 13 | 14 | String floatValueInString2 = "123.45"; 15 | 16 | Float floatValue2 = Float.valueOf(floatValueInString2); 17 | 18 | System.out.println("Float value in String : " + floatValueInString2); 19 | System.out.println("String to Wrapper Float value : " + floatValue2); 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/com/javaprogramto/arrays/bytearray/CharsetEncode.java: -------------------------------------------------------------------------------- 1 | package com.javaprogramto.arrays.bytearray; 2 | 3 | import java.nio.ByteBuffer; 4 | import java.nio.charset.Charset; 5 | import java.nio.charset.StandardCharsets; 6 | 7 | public class CharsetEncode { 8 | 9 | public static void main(String[] args) { 10 | 11 | // creating string 12 | String inputStr = "javaprogrmto.com जावा"; 13 | 14 | // create charset object 15 | Charset charset = StandardCharsets.US_ASCII; 16 | 17 | // encoding string 18 | ByteBuffer buffer = charset.encode(inputStr); 19 | 20 | // ByteBuffer to byte[] array 21 | byte[] array = buffer.array(); 22 | 23 | // printing byte array 24 | for (int j = 0; j < array.length; j++) { 25 | System.out.print(" " + array[j]); 26 | } 27 | 28 | } 29 | } 30 | --------------------------------------------------------------------------------