├── .editorconfig ├── .github └── workflows │ └── workflow.yml ├── .gitignore ├── .travis.yml ├── LICENSE ├── Makefile ├── README.md ├── build.gradle ├── gradle └── wrapper │ ├── gradle-wrapper.jar │ └── gradle-wrapper.properties ├── gradlew ├── gradlew.bat ├── src ├── main │ ├── java │ │ └── tv │ │ │ └── codely │ │ │ └── solid_principles │ │ │ ├── dependency_inversion_principle │ │ │ ├── User.java │ │ │ ├── stage_1_instantiating_from_clients │ │ │ │ ├── HardcodedInMemoryUsersRepository.java │ │ │ │ └── UserSearcher.java │ │ │ ├── stage_2_0_dependency_injection │ │ │ │ ├── HardcodedInMemoryUsersRepository.java │ │ │ │ └── UserSearcher.java │ │ │ ├── stage_2_1_dependency_injection_of_constant_parameters │ │ │ │ ├── HardcodedInMemoryUsersRepository.java │ │ │ │ └── UserSearcher.java │ │ │ └── stage_3_dependency_inversion │ │ │ │ ├── UserSearcher.java │ │ │ │ └── UsersRepository.java │ │ │ └── liskov_substitution_principle │ │ │ ├── Rectangle.java │ │ │ └── Square.java │ └── resources │ │ └── log4j2.properties └── test │ ├── java │ └── tv │ │ └── codely │ │ └── solid_principles │ │ ├── dependency_inversion_principle │ │ ├── stage_1_instantiating_from_clients │ │ │ └── UserSearcherShould.java │ │ ├── stage_2_0_dependency_injection │ │ │ └── UserSearcherShould.java │ │ ├── stage_2_1_dependency_injection_of_constant_parameters │ │ │ └── UserSearcherShould.java │ │ └── stage_3_dependency_inversion │ │ │ ├── CodelyTvStaffUsersRepository.java │ │ │ ├── EmptyUsersRepository.java │ │ │ ├── UserMother.java │ │ │ └── UserSearcherShould.java │ │ └── liskov_substitution_principle │ │ ├── RectangleShould.java │ │ └── SquareShould.java │ └── resources │ └── log4j2.properties └── var └── log └── .gitkeep /.editorconfig: -------------------------------------------------------------------------------- 1 | root = true 2 | 3 | [*] 4 | charset = utf-8 5 | end_of_line = lf 6 | insert_final_newline = true 7 | trim_trailing_whitespace = true 8 | 9 | [*.java] 10 | indent_size = 4 11 | indent_style = space 12 | -------------------------------------------------------------------------------- /.github/workflows/workflow.yml: -------------------------------------------------------------------------------- 1 | name: Main Workflow 2 | 3 | on: [push] 4 | 5 | jobs: 6 | build: 7 | 8 | runs-on: ubuntu-latest 9 | 10 | steps: 11 | - uses: actions/checkout@v1 12 | - name: Set up JDK 1.8 13 | uses: actions/setup-java@v1 14 | with: 15 | java-version: 1.8 16 | - name: Assemble 17 | run: ./gradlew assemble --warning-mode all 18 | - name: Check 19 | run: ./gradlew check --warning-mode all 20 | 21 | -------------------------------------------------------------------------------- /.gitignore: -------------------------------------------------------------------------------- 1 | # Gradle 2 | .gradle 3 | build/ 4 | /out 5 | # Ignore Gradle GUI config 6 | gradle-app.setting 7 | 8 | var/log/* 9 | !var/log/.gitkeep 10 | -------------------------------------------------------------------------------- /.travis.yml: -------------------------------------------------------------------------------- 1 | language: java 2 | 3 | jdk: 4 | - openjdk11 5 | - oraclejdk11 6 | 7 | os: 8 | - linux 9 | - osx 10 | 11 | before_cache: 12 | - rm -f $HOME/.gradle/caches/modules-2/modules-2.lock 13 | - rm -fr $HOME/.gradle/caches/*/plugin-resolution/ 14 | 15 | cache: 16 | directories: 17 | - $HOME/.gradle/caches/ 18 | - $HOME/.gradle/wrapper/ 19 | 20 | # Run commands before TravisCI install step only in some cases 21 | # More info: https://docs.travis-ci.com/user/multi-os/#example-multi-os-build-matrix 22 | before_install: 23 | - if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then brew update; fi 24 | 25 | # Override default install process on TravisCI 26 | # Avoid default `gradlew assemble` execution. Be explicit about it on the `script` section. 27 | # More info: https://github.com/travis-ci/travis-ci/issues/8667 28 | install: true 29 | 30 | # Build pipeline 31 | # Compile before running the tests in order to easily check which task could be failing. 32 | script: 33 | - ./gradlew assemble --warning-mode all 34 | - ./gradlew check --warning-mode all 35 | -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | MIT License 2 | 3 | Copyright (c) 2018 CodelyTV 4 | 5 | Permission is hereby granted, free of charge, to any person obtaining a copy 6 | of this software and associated documentation files (the "Software"), to deal 7 | in the Software without restriction, including without limitation the rights 8 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 9 | copies of the Software, and to permit persons to whom the Software is 10 | furnished to do so, subject to the following conditions: 11 | 12 | The above copyright notice and this permission notice shall be included in all 13 | copies or substantial portions of the Software. 14 | 15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 21 | SOFTWARE. 22 | -------------------------------------------------------------------------------- /Makefile: -------------------------------------------------------------------------------- 1 | .PONY: all build test 2 | 3 | all: build 4 | 5 | build: 6 | @./gradlew assemble --warning-mode all 7 | 8 | test: 9 | @./gradlew check --warning-mode all 10 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # ☕⚛ SOLID principles examples in Java 2 | 3 | 4 | 5 | 6 | > ⚛ Learn SOLID principles by examples 7 | 8 | [![CodelyTV](https://img.shields.io/badge/codely-tv-green.svg?style=flat-square)](https://codely.tv) 9 | [![Workflow Status](https://github.com/CodelyTV/java-solid-examples/workflows/Main%20Workflow/badge.svg)](https://github.com/CodelyTV/java-solid-examples/actions) 10 | 11 | ## ℹ️ Introduction 12 | 13 | This is a repository intended to serve as illustrative examples for the course ["Principios SOLID Aplicados" (Spanish)](https://pro.codely.tv/library/principios-solid-aplicados/77070/about/?utm_source=github&utm_medium=social&utm_campaign=java-solid-examples). 14 | 15 | ## 🏁 How To Start 16 | 17 | 1. Install Java 8: `brew cask install corretto8` 18 | 2. Set it as your default JVM: `export JAVA_HOME='/Library/Java/JavaVirtualMachines/amazon-corretto-8.jdk/Contents/Home'` 19 | 3. Clone this repository: `git clone https://github.com/CodelyTV/java-solid-examples`. 20 | 4. Execute some [Gradle lifecycle tasks](https://docs.gradle.org/current/userguide/java_plugin.html#lifecycle_tasks) in order to check everything is OK: 21 | 1. Create [the project JAR](https://docs.gradle.org/current/userguide/java_plugin.html#sec:jar): `make build` 22 | 2. Run the tests and plugins verification tasks: `make test` 23 | 5. Start playing around with the different examples of each SOLID principle. You have explanations here and in the test code 🙂 24 | 25 | ## ☝️ How to update dependencies 26 | 27 | * Gradle (current version: 5.6 - [releases](https://gradle.org/releases/)): 28 | `./gradlew wrapper --gradle-version=5.6 --distribution-type=bin` or modifying the [gradle-wrapper.properties](gradle/wrapper/gradle-wrapper.properties#L3) 29 | * JUnit (current version: 5.5.1 - [releases](https://junit.org/junit5/docs/snapshot/release-notes/index.html)): 30 | [`build.gradle:11`](build.gradle#L11-L12) 31 | 32 | ## 💡 Related repositories 33 | 34 | ### ☕ Java 35 | 36 | * 📂 [Java Basic Skeleton](https://github.com/CodelyTV/java-basic-skeleton) 37 | * ⚛ [Java OOP Examples](https://github.com/CodelyTV/java-oop-examples) 38 | * 🧱 [Java SOLID Examples](https://github.com/CodelyTV/java-solid-examples) 39 | * 🥦 [Java DDD Example](https://github.com/CodelyTV/java-ddd-example) 40 | 41 | ### 🐘 PHP 42 | 43 | * 📂 [PHP Basic Skeleton](https://github.com/CodelyTV/php-basic-skeleton) 44 | * 🎩 [PHP DDD Skeleton](https://github.com/CodelyTV/php-ddd-skeleton) 45 | * 🥦 [PHP DDD Example](https://github.com/CodelyTV/php-ddd-example) 46 | 47 | ### 🧬 Scala 48 | 49 | * 📂 [Scala Basic Skeleton](https://github.com/CodelyTV/scala-basic-skeleton) 50 | * ⚡ [Scala Basic Skeleton (g8 template)](https://github.com/CodelyTV/scala-basic-skeleton.g8) 51 | * ⚛ [Scala Examples](https://github.com/CodelyTV/scala-examples) 52 | * 🥦 [Scala DDD Example](https://github.com/CodelyTV/scala-ddd-example) 53 | 54 | 55 | ## Liskov Substitution Principle (LSP) 56 | 57 | * Package: `tv.codely.solid_principles.liskov_substitution_principle` 58 | * [Production code](src/main/java/tv/codely/solid_principles/liskov_substitution_principle) 59 | * [Tests code with explanations](src/test/java/tv/codely/solid_principles/liskov_substitution_principle) 60 | 61 | ## Dependency Inversion Principle (DIP) 62 | 63 | * Package: `tv.codely.solid_principles.dependency_inversion_principle` 64 | * [Production code](src/main/java/tv/codely/solid_principles/dependency_inversion_principle) 65 | * [Tests code with explanations](src/test/java/tv/codely/solid_principles/dependency_inversion_principle) 66 | 67 | ## About 68 | 69 | This hopefully helpful examples have been implemented by [CodelyTV](https://github.com/CodelyTV) and [contributors](https://github.com/CodelyTV/solid-principles-java-examples/graphs/contributors). 70 | 71 | Pull Requests are welcome. We would suggest oppening an issue before actually coding your Pull Request in order to ask for feedback 🙂 72 | 73 | ## License 74 | 75 | The MIT License (MIT). Please see [License](LICENSE) for more information. 76 | -------------------------------------------------------------------------------- /build.gradle: -------------------------------------------------------------------------------- 1 | apply plugin: 'java' 2 | 3 | sourceCompatibility = 1.8 4 | targetCompatibility = 1.8 5 | 6 | repositories { 7 | mavenCentral() 8 | } 9 | 10 | dependencies { 11 | implementation 'org.apache.logging.log4j:log4j-core:2.12.1' 12 | implementation 'com.vlkan.log4j2:log4j2-logstash-layout:0.19' 13 | 14 | testCompile 'org.junit.jupiter:junit-jupiter-api:5.5.1' 15 | testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.5.1' 16 | } 17 | 18 | test { 19 | useJUnitPlatform() 20 | 21 | testLogging { 22 | events "passed", "skipped", "failed" 23 | } 24 | } 25 | -------------------------------------------------------------------------------- /gradle/wrapper/gradle-wrapper.jar: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/CodelyTV/java-solid-examples/44600ce024ef957a05e0c4fbe9a76b283b0f84a1/gradle/wrapper/gradle-wrapper.jar -------------------------------------------------------------------------------- /gradle/wrapper/gradle-wrapper.properties: -------------------------------------------------------------------------------- 1 | distributionBase=GRADLE_USER_HOME 2 | distributionPath=wrapper/dists 3 | distributionUrl=https\://services.gradle.org/distributions/gradle-5.6-bin.zip 4 | zipStoreBase=GRADLE_USER_HOME 5 | zipStorePath=wrapper/dists 6 | -------------------------------------------------------------------------------- /gradlew: -------------------------------------------------------------------------------- 1 | #!/usr/bin/env sh 2 | 3 | ############################################################################## 4 | ## 5 | ## Gradle start up script for UN*X 6 | ## 7 | ############################################################################## 8 | 9 | # Attempt to set APP_HOME 10 | # Resolve links: $0 may be a link 11 | PRG="$0" 12 | # Need this for relative symlinks. 13 | while [ -h "$PRG" ] ; do 14 | ls=`ls -ld "$PRG"` 15 | link=`expr "$ls" : '.*-> \(.*\)$'` 16 | if expr "$link" : '/.*' > /dev/null; then 17 | PRG="$link" 18 | else 19 | PRG=`dirname "$PRG"`"/$link" 20 | fi 21 | done 22 | SAVED="`pwd`" 23 | cd "`dirname \"$PRG\"`/" >/dev/null 24 | APP_HOME="`pwd -P`" 25 | cd "$SAVED" >/dev/null 26 | 27 | APP_NAME="Gradle" 28 | APP_BASE_NAME=`basename "$0"` 29 | 30 | # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script. 31 | DEFAULT_JVM_OPTS="" 32 | 33 | # Use the maximum available, or set MAX_FD != -1 to use that value. 34 | MAX_FD="maximum" 35 | 36 | warn () { 37 | echo "$*" 38 | } 39 | 40 | die () { 41 | echo 42 | echo "$*" 43 | echo 44 | exit 1 45 | } 46 | 47 | # OS specific support (must be 'true' or 'false'). 48 | cygwin=false 49 | msys=false 50 | darwin=false 51 | nonstop=false 52 | case "`uname`" in 53 | CYGWIN* ) 54 | cygwin=true 55 | ;; 56 | Darwin* ) 57 | darwin=true 58 | ;; 59 | MINGW* ) 60 | msys=true 61 | ;; 62 | NONSTOP* ) 63 | nonstop=true 64 | ;; 65 | esac 66 | 67 | CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar 68 | 69 | # Determine the Java command to use to start the JVM. 70 | if [ -n "$JAVA_HOME" ] ; then 71 | if [ -x "$JAVA_HOME/jre/sh/java" ] ; then 72 | # IBM's JDK on AIX uses strange locations for the executables 73 | JAVACMD="$JAVA_HOME/jre/sh/java" 74 | else 75 | JAVACMD="$JAVA_HOME/bin/java" 76 | fi 77 | if [ ! -x "$JAVACMD" ] ; then 78 | die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME 79 | 80 | Please set the JAVA_HOME variable in your environment to match the 81 | location of your Java installation." 82 | fi 83 | else 84 | JAVACMD="java" 85 | which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 86 | 87 | Please set the JAVA_HOME variable in your environment to match the 88 | location of your Java installation." 89 | fi 90 | 91 | # Increase the maximum file descriptors if we can. 92 | if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then 93 | MAX_FD_LIMIT=`ulimit -H -n` 94 | if [ $? -eq 0 ] ; then 95 | if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then 96 | MAX_FD="$MAX_FD_LIMIT" 97 | fi 98 | ulimit -n $MAX_FD 99 | if [ $? -ne 0 ] ; then 100 | warn "Could not set maximum file descriptor limit: $MAX_FD" 101 | fi 102 | else 103 | warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT" 104 | fi 105 | fi 106 | 107 | # For Darwin, add options to specify how the application appears in the dock 108 | if $darwin; then 109 | GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\"" 110 | fi 111 | 112 | # For Cygwin, switch paths to Windows format before running java 113 | if $cygwin ; then 114 | APP_HOME=`cygpath --path --mixed "$APP_HOME"` 115 | CLASSPATH=`cygpath --path --mixed "$CLASSPATH"` 116 | JAVACMD=`cygpath --unix "$JAVACMD"` 117 | 118 | # We build the pattern for arguments to be converted via cygpath 119 | ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null` 120 | SEP="" 121 | for dir in $ROOTDIRSRAW ; do 122 | ROOTDIRS="$ROOTDIRS$SEP$dir" 123 | SEP="|" 124 | done 125 | OURCYGPATTERN="(^($ROOTDIRS))" 126 | # Add a user-defined pattern to the cygpath arguments 127 | if [ "$GRADLE_CYGPATTERN" != "" ] ; then 128 | OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)" 129 | fi 130 | # Now convert the arguments - kludge to limit ourselves to /bin/sh 131 | i=0 132 | for arg in "$@" ; do 133 | CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -` 134 | CHECK2=`echo "$arg"|egrep -c "^-"` ### Determine if an option 135 | 136 | if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then ### Added a condition 137 | eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"` 138 | else 139 | eval `echo args$i`="\"$arg\"" 140 | fi 141 | i=$((i+1)) 142 | done 143 | case $i in 144 | (0) set -- ;; 145 | (1) set -- "$args0" ;; 146 | (2) set -- "$args0" "$args1" ;; 147 | (3) set -- "$args0" "$args1" "$args2" ;; 148 | (4) set -- "$args0" "$args1" "$args2" "$args3" ;; 149 | (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;; 150 | (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;; 151 | (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;; 152 | (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;; 153 | (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;; 154 | esac 155 | fi 156 | 157 | # Escape application args 158 | save () { 159 | for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done 160 | echo " " 161 | } 162 | APP_ARGS=$(save "$@") 163 | 164 | # Collect all arguments for the java command, following the shell quoting and substitution rules 165 | eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS" 166 | 167 | # by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong 168 | if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then 169 | cd "$(dirname "$0")" 170 | fi 171 | 172 | exec "$JAVACMD" "$@" 173 | -------------------------------------------------------------------------------- /gradlew.bat: -------------------------------------------------------------------------------- 1 | @if "%DEBUG%" == "" @echo off 2 | @rem ########################################################################## 3 | @rem 4 | @rem Gradle startup script for Windows 5 | @rem 6 | @rem ########################################################################## 7 | 8 | @rem Set local scope for the variables with windows NT shell 9 | if "%OS%"=="Windows_NT" setlocal 10 | 11 | set DIRNAME=%~dp0 12 | if "%DIRNAME%" == "" set DIRNAME=. 13 | set APP_BASE_NAME=%~n0 14 | set APP_HOME=%DIRNAME% 15 | 16 | @rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script. 17 | set DEFAULT_JVM_OPTS= 18 | 19 | @rem Find java.exe 20 | if defined JAVA_HOME goto findJavaFromJavaHome 21 | 22 | set JAVA_EXE=java.exe 23 | %JAVA_EXE% -version >NUL 2>&1 24 | if "%ERRORLEVEL%" == "0" goto init 25 | 26 | echo. 27 | echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 28 | echo. 29 | echo Please set the JAVA_HOME variable in your environment to match the 30 | echo location of your Java installation. 31 | 32 | goto fail 33 | 34 | :findJavaFromJavaHome 35 | set JAVA_HOME=%JAVA_HOME:"=% 36 | set JAVA_EXE=%JAVA_HOME%/bin/java.exe 37 | 38 | if exist "%JAVA_EXE%" goto init 39 | 40 | echo. 41 | echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 42 | echo. 43 | echo Please set the JAVA_HOME variable in your environment to match the 44 | echo location of your Java installation. 45 | 46 | goto fail 47 | 48 | :init 49 | @rem Get command-line arguments, handling Windows variants 50 | 51 | if not "%OS%" == "Windows_NT" goto win9xME_args 52 | 53 | :win9xME_args 54 | @rem Slurp the command line arguments. 55 | set CMD_LINE_ARGS= 56 | set _SKIP=2 57 | 58 | :win9xME_args_slurp 59 | if "x%~1" == "x" goto execute 60 | 61 | set CMD_LINE_ARGS=%* 62 | 63 | :execute 64 | @rem Setup the command line 65 | 66 | set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar 67 | 68 | @rem Execute Gradle 69 | "%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS% 70 | 71 | :end 72 | @rem End local scope for the variables with windows NT shell 73 | if "%ERRORLEVEL%"=="0" goto mainEnd 74 | 75 | :fail 76 | rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of 77 | rem the _cmd.exe /c_ return code! 78 | if not "" == "%GRADLE_EXIT_CONSOLE%" exit 1 79 | exit /b 1 80 | 81 | :mainEnd 82 | if "%OS%"=="Windows_NT" endlocal 83 | 84 | :omega 85 | -------------------------------------------------------------------------------- /src/main/java/tv/codely/solid_principles/dependency_inversion_principle/User.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.dependency_inversion_principle; 2 | 3 | import java.util.Objects; 4 | 5 | final public class User { 6 | private Integer id; 7 | private String name; 8 | 9 | public User(Integer id, String name) { 10 | this.id = id; 11 | this.name = name; 12 | } 13 | 14 | @Override 15 | public boolean equals(Object other) { 16 | if (this == other) return true; 17 | 18 | if (!(other instanceof User)) return false; 19 | 20 | User otherUser = (User) other; 21 | return Objects.equals(id, otherUser.id) && Objects.equals(name, otherUser.name); 22 | } 23 | 24 | @Override 25 | public int hashCode() { 26 | return Objects.hash(id, name); 27 | } 28 | } 29 | -------------------------------------------------------------------------------- /src/main/java/tv/codely/solid_principles/dependency_inversion_principle/stage_1_instantiating_from_clients/HardcodedInMemoryUsersRepository.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.dependency_inversion_principle.stage_1_instantiating_from_clients; 2 | 3 | import tv.codely.solid_principles.dependency_inversion_principle.User; 4 | 5 | import java.util.Collections; 6 | import java.util.HashMap; 7 | import java.util.Map; 8 | import java.util.Optional; 9 | 10 | final class HardcodedInMemoryUsersRepository { 11 | private Map users = Collections.unmodifiableMap(new HashMap() { 12 | { 13 | put(1, new User(1, "Rafa")); 14 | put(2, new User(2, "Javi")); 15 | } 16 | }); 17 | 18 | public Optional search(Integer id) { 19 | return Optional.ofNullable(users.get(id)); 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/tv/codely/solid_principles/dependency_inversion_principle/stage_1_instantiating_from_clients/UserSearcher.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.dependency_inversion_principle.stage_1_instantiating_from_clients; 2 | 3 | import tv.codely.solid_principles.dependency_inversion_principle.User; 4 | 5 | import java.util.Optional; 6 | 7 | final class UserSearcher { 8 | private HardcodedInMemoryUsersRepository usersRepository = 9 | new HardcodedInMemoryUsersRepository(); 10 | 11 | public Optional search(Integer id) { 12 | return usersRepository.search(id); 13 | } 14 | } 15 | -------------------------------------------------------------------------------- /src/main/java/tv/codely/solid_principles/dependency_inversion_principle/stage_2_0_dependency_injection/HardcodedInMemoryUsersRepository.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.dependency_inversion_principle.stage_2_0_dependency_injection; 2 | 3 | import tv.codely.solid_principles.dependency_inversion_principle.User; 4 | 5 | import java.util.Collections; 6 | import java.util.HashMap; 7 | import java.util.Map; 8 | import java.util.Optional; 9 | 10 | final class HardcodedInMemoryUsersRepository { 11 | private Map users = Collections.unmodifiableMap(new HashMap() { 12 | { 13 | put(1, new User(1, "Rafa")); 14 | put(2, new User(2, "Javi")); 15 | } 16 | }); 17 | 18 | public Optional search(Integer id) { 19 | return Optional.ofNullable(users.get(id)); 20 | } 21 | } 22 | -------------------------------------------------------------------------------- /src/main/java/tv/codely/solid_principles/dependency_inversion_principle/stage_2_0_dependency_injection/UserSearcher.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.dependency_inversion_principle.stage_2_0_dependency_injection; 2 | 3 | import tv.codely.solid_principles.dependency_inversion_principle.User; 4 | 5 | import java.util.Optional; 6 | 7 | final class UserSearcher { 8 | private HardcodedInMemoryUsersRepository usersRepository; 9 | 10 | public UserSearcher(HardcodedInMemoryUsersRepository usersRepository) { 11 | this.usersRepository = usersRepository; 12 | } 13 | 14 | public Optional search(Integer id) { 15 | return usersRepository.search(id); 16 | } 17 | } 18 | -------------------------------------------------------------------------------- /src/main/java/tv/codely/solid_principles/dependency_inversion_principle/stage_2_1_dependency_injection_of_constant_parameters/HardcodedInMemoryUsersRepository.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.dependency_inversion_principle.stage_2_1_dependency_injection_of_constant_parameters; 2 | 3 | import tv.codely.solid_principles.dependency_inversion_principle.User; 4 | 5 | import java.util.Map; 6 | import java.util.Optional; 7 | 8 | final class HardcodedInMemoryUsersRepository { 9 | private Map users; 10 | 11 | public HardcodedInMemoryUsersRepository(Map users) { 12 | this.users = users; 13 | } 14 | 15 | public Optional search(Integer id) { 16 | return Optional.ofNullable(users.get(id)); 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/main/java/tv/codely/solid_principles/dependency_inversion_principle/stage_2_1_dependency_injection_of_constant_parameters/UserSearcher.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.dependency_inversion_principle.stage_2_1_dependency_injection_of_constant_parameters; 2 | 3 | import tv.codely.solid_principles.dependency_inversion_principle.User; 4 | 5 | import java.util.Optional; 6 | 7 | final class UserSearcher { 8 | private HardcodedInMemoryUsersRepository usersRepository; 9 | 10 | public UserSearcher(HardcodedInMemoryUsersRepository usersRepository) { 11 | this.usersRepository = usersRepository; 12 | } 13 | 14 | public Optional search(Integer id) { 15 | return usersRepository.search(id); 16 | } 17 | } 18 | -------------------------------------------------------------------------------- /src/main/java/tv/codely/solid_principles/dependency_inversion_principle/stage_3_dependency_inversion/UserSearcher.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.dependency_inversion_principle.stage_3_dependency_inversion; 2 | 3 | import tv.codely.solid_principles.dependency_inversion_principle.User; 4 | 5 | import java.util.Optional; 6 | 7 | final class UserSearcher { 8 | private UsersRepository usersRepository; 9 | 10 | public UserSearcher(UsersRepository usersRepository) { 11 | this.usersRepository = usersRepository; 12 | } 13 | 14 | public Optional search(Integer id) { 15 | return usersRepository.search(id); 16 | } 17 | } 18 | -------------------------------------------------------------------------------- /src/main/java/tv/codely/solid_principles/dependency_inversion_principle/stage_3_dependency_inversion/UsersRepository.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.dependency_inversion_principle.stage_3_dependency_inversion; 2 | 3 | import tv.codely.solid_principles.dependency_inversion_principle.User; 4 | 5 | import java.util.Optional; 6 | 7 | public interface UsersRepository { 8 | Optional search(Integer id); 9 | } 10 | -------------------------------------------------------------------------------- /src/main/java/tv/codely/solid_principles/liskov_substitution_principle/Rectangle.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.liskov_substitution_principle; 2 | 3 | class Rectangle { 4 | private Integer length; 5 | private Integer width; 6 | 7 | Rectangle(Integer length, Integer width) { 8 | this.length = length; 9 | this.width = width; 10 | } 11 | 12 | void setLength(Integer length) { 13 | this.length = length; 14 | } 15 | 16 | void setWidth(Integer width) { 17 | this.width = width; 18 | } 19 | 20 | Integer getArea() { 21 | return this.length * this.width; 22 | } 23 | } 24 | -------------------------------------------------------------------------------- /src/main/java/tv/codely/solid_principles/liskov_substitution_principle/Square.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.liskov_substitution_principle; 2 | 3 | final class Square extends Rectangle { 4 | Square(Integer lengthAndWidth) { 5 | super(lengthAndWidth, lengthAndWidth); 6 | } 7 | 8 | @Override 9 | public void setLength(Integer length) { 10 | super.setLength(length); 11 | super.setWidth(length); 12 | } 13 | 14 | @Override 15 | public void setWidth(Integer width) { 16 | super.setWidth(width); 17 | super.setLength(width); 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/main/resources/log4j2.properties: -------------------------------------------------------------------------------- 1 | name = CodelyTvJavaSolidExamples 2 | property.filename = logs 3 | appenders = console, file 4 | 5 | status = warn 6 | 7 | appender.console.name = CONSOLE 8 | appender.console.type = CONSOLE 9 | appender.console.target = SYSTEM_OUT 10 | 11 | appender.console.logstash.type = LogstashLayout 12 | appender.console.logstash.dateTimeFormatPattern = yyyy-MM-dd'T'HH:mm:ss.SSSZZZ 13 | appender.console.logstash.eventTemplateUri = classpath:LogstashJsonEventLayoutV1.json 14 | appender.console.logstash.prettyPrintEnabled = true 15 | appender.console.logstash.stackTraceEnabled = true 16 | 17 | appender.file.type = File 18 | appender.file.name = LOGFILE 19 | appender.file.fileName=var/log/java-solid-examples.log 20 | appender.file.logstash.type=LogstashLayout 21 | appender.file.logstash.dateTimeFormatPattern = yyyy-MM-dd'T'HH:mm:ss.SSSZZZ 22 | appender.file.logstash.eventTemplateUri = classpath:LogstashJsonEventLayoutV1.json 23 | appender.file.logstash.prettyPrintEnabled = false 24 | appender.file.logstash.stackTraceEnabled = true 25 | 26 | loggers = file 27 | logger.file.name = tv.codely.solid_principles 28 | logger.file.level = info 29 | logger.file.appenderRefs = file 30 | logger.file.appenderRef.file.ref = LOGFILE 31 | 32 | rootLogger.level = info 33 | rootLogger.appenderRefs = stdout 34 | rootLogger.appenderRef.stdout.ref = CONSOLE 35 | -------------------------------------------------------------------------------- /src/test/java/tv/codely/solid_principles/dependency_inversion_principle/stage_1_instantiating_from_clients/UserSearcherShould.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.dependency_inversion_principle.stage_1_instantiating_from_clients; 2 | 3 | import org.junit.jupiter.api.Test; 4 | import tv.codely.solid_principles.dependency_inversion_principle.User; 5 | 6 | import java.util.Optional; 7 | 8 | import static org.junit.jupiter.api.Assertions.assertEquals; 9 | 10 | final class UserSearcherShould { 11 | @Test 12 | void find_existing_users() { 13 | UserSearcher userSearcher = new UserSearcher(); 14 | 15 | // We would be coupled to the actual HardcodedInMemoryUsersRepository implementation. 16 | // We don't have the option to set test users as we would have to do if we had a real database repository. 17 | Integer existingUserId = 1; 18 | Optional expectedUser = Optional.of(new User(1, "Rafa")); 19 | 20 | assertEquals(expectedUser, userSearcher.search(existingUserId)); 21 | } 22 | 23 | @Test 24 | void not_find_non_existing_users() { 25 | UserSearcher userSearcher = new UserSearcher(); 26 | 27 | Integer nonExistingUserId = 5; 28 | Optional expectedEmptyResult = Optional.empty(); 29 | 30 | assertEquals(expectedEmptyResult, userSearcher.search(nonExistingUserId)); 31 | } 32 | } 33 | -------------------------------------------------------------------------------- /src/test/java/tv/codely/solid_principles/dependency_inversion_principle/stage_2_0_dependency_injection/UserSearcherShould.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.dependency_inversion_principle.stage_2_0_dependency_injection; 2 | 3 | import org.junit.jupiter.api.Test; 4 | import tv.codely.solid_principles.dependency_inversion_principle.User; 5 | 6 | import java.util.Optional; 7 | 8 | import static org.junit.jupiter.api.Assertions.assertEquals; 9 | 10 | final class UserSearcherShould { 11 | @Test 12 | void find_existing_users() { 13 | // Now we're injecting the HardcodedInMemoryUsersRepository instance through the UserSearcher constructor. 14 | // 👍 Win: We've moved away from the UserSearcher the instantiation logic of the HardcodedInMemoryUsersRepository class allowing us to centralize it. 15 | // 👍 Win: We're exposing the couplings of the UserSearcher class. 16 | HardcodedInMemoryUsersRepository usersRepository = new HardcodedInMemoryUsersRepository(); 17 | UserSearcher userSearcher = new UserSearcher(usersRepository); 18 | 19 | Integer existingUserId = 1; 20 | Optional expectedUser = Optional.of(new User(1, "Rafa")); 21 | 22 | assertEquals(expectedUser, userSearcher.search(existingUserId)); 23 | } 24 | 25 | @Test 26 | void not_find_non_existing_users() { 27 | HardcodedInMemoryUsersRepository usersRepository = new HardcodedInMemoryUsersRepository(); 28 | UserSearcher userSearcher = new UserSearcher(usersRepository); 29 | 30 | Integer nonExistingUserId = 5; 31 | Optional expectedEmptyResult = Optional.empty(); 32 | 33 | assertEquals(expectedEmptyResult, userSearcher.search(nonExistingUserId)); 34 | } 35 | } 36 | -------------------------------------------------------------------------------- /src/test/java/tv/codely/solid_principles/dependency_inversion_principle/stage_2_1_dependency_injection_of_constant_parameters/UserSearcherShould.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.dependency_inversion_principle.stage_2_1_dependency_injection_of_constant_parameters; 2 | 3 | import org.junit.jupiter.api.Test; 4 | import tv.codely.solid_principles.dependency_inversion_principle.User; 5 | 6 | import java.util.Collections; 7 | import java.util.HashMap; 8 | import java.util.Map; 9 | import java.util.Optional; 10 | 11 | import static org.junit.jupiter.api.Assertions.assertEquals; 12 | 13 | final class UserSearcherShould { 14 | @Test 15 | void find_existing_users() { 16 | // Now we're also injecting the constant parameters needed by the HardcodedInMemoryUsersRepository through its constructor. 17 | // 👍 Win: We can send different parameters depending on the environment. 18 | // That is, in our production environment we would have actual users, 19 | // while in our tests cases we will set only the needed ones to run our test cases 20 | int rafaId = 1; 21 | User rafa = new User(rafaId, "Rafa"); 22 | 23 | Map users = Collections.unmodifiableMap(new HashMap() { 24 | { 25 | put(rafaId, rafa); 26 | } 27 | }); 28 | HardcodedInMemoryUsersRepository usersRepository = new HardcodedInMemoryUsersRepository(users); 29 | UserSearcher userSearcher = new UserSearcher(usersRepository); 30 | 31 | Optional expectedUser = Optional.of(rafa); 32 | 33 | assertEquals(expectedUser, userSearcher.search(rafaId)); 34 | } 35 | 36 | @Test 37 | void not_find_non_existing_users() { 38 | Map users = Collections.emptyMap(); 39 | HardcodedInMemoryUsersRepository usersRepository = new HardcodedInMemoryUsersRepository(users); 40 | UserSearcher userSearcher = new UserSearcher(usersRepository); 41 | 42 | // 👍 Win: Now we don't have to be coupled of the actual HardcodedInMemoryUsersRepository users. 43 | // We can send a random user ID in order to force an empty result because we've set an empty map as the system users. 44 | Integer nonExistingUserId = 1; 45 | Optional expectedEmptyResult = Optional.empty(); 46 | 47 | assertEquals(expectedEmptyResult, userSearcher.search(nonExistingUserId)); 48 | } 49 | } 50 | -------------------------------------------------------------------------------- /src/test/java/tv/codely/solid_principles/dependency_inversion_principle/stage_3_dependency_inversion/CodelyTvStaffUsersRepository.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.dependency_inversion_principle.stage_3_dependency_inversion; 2 | 3 | import tv.codely.solid_principles.dependency_inversion_principle.User; 4 | 5 | import java.util.Collections; 6 | import java.util.HashMap; 7 | import java.util.Map; 8 | import java.util.Optional; 9 | 10 | // ℹ️ User repository for test usage. It is used as a _Test double_, more specifically, it's a _Mother_. 11 | // More info on the difference between Mothers and Mocks: https://martinfowler.com/articles/mocksArentMothers.html 12 | final class CodelyTvStaffUsersRepository implements UsersRepository { 13 | private Map users = Collections.unmodifiableMap(new HashMap() { 14 | { 15 | put(UserMother.RAFA_ID, UserMother.rafa()); 16 | put(UserMother.JAVI_ID, UserMother.javi()); 17 | } 18 | }); 19 | 20 | @Override 21 | public Optional search(Integer id) { 22 | return Optional.ofNullable(users.get(id)); 23 | } 24 | } 25 | 26 | -------------------------------------------------------------------------------- /src/test/java/tv/codely/solid_principles/dependency_inversion_principle/stage_3_dependency_inversion/EmptyUsersRepository.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.dependency_inversion_principle.stage_3_dependency_inversion; 2 | 3 | import tv.codely.solid_principles.dependency_inversion_principle.User; 4 | 5 | import java.util.Optional; 6 | 7 | // ℹ️ User repository for test usage. It is used as a _Test double_, more specifically, it's a _Fake_. 8 | // More info on the main types of Test doubles: https://testing.googleblog.com/2013/07/testing-on-toilet-know-your-test-doubles.html 9 | final class EmptyUsersRepository implements UsersRepository { 10 | @Override 11 | public Optional search(Integer id) { 12 | return Optional.empty(); 13 | } 14 | } 15 | -------------------------------------------------------------------------------- /src/test/java/tv/codely/solid_principles/dependency_inversion_principle/stage_3_dependency_inversion/UserMother.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.dependency_inversion_principle.stage_3_dependency_inversion; 2 | 3 | import tv.codely.solid_principles.dependency_inversion_principle.User; 4 | 5 | final class UserMother { 6 | static final int RAFA_ID = 1; 7 | static final int JAVI_ID = 2; 8 | 9 | private static final String RAFA_NAME = "Rafa"; 10 | private static final String JAVI_NAME = "Javi"; 11 | 12 | static User rafa() { 13 | return new User(RAFA_ID, RAFA_NAME); 14 | } 15 | 16 | static User javi() { 17 | return new User(JAVI_ID, JAVI_NAME); 18 | } 19 | } 20 | -------------------------------------------------------------------------------- /src/test/java/tv/codely/solid_principles/dependency_inversion_principle/stage_3_dependency_inversion/UserSearcherShould.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.dependency_inversion_principle.stage_3_dependency_inversion; 2 | 3 | import org.junit.jupiter.api.Test; 4 | import tv.codely.solid_principles.dependency_inversion_principle.User; 5 | 6 | import java.util.Optional; 7 | 8 | import static org.junit.jupiter.api.Assertions.assertEquals; 9 | 10 | final class UserSearcherShould { 11 | @Test 12 | void find_existing_users() { 13 | // Now we're injecting to the UserSearcher use case different implementation of the new UserRepository interface. 14 | // 👍 Win: We can replace the actual implementation of the UsersRepository used by the UserSearcher. 15 | // That is, we'll not have to modify a single line of the UserSearcher class despite of changing our whole infrastructure. 16 | // This is a big win in terms of being more tolerant to changes. 17 | // 👍 Win: It also make it easier for us to test the UserSearcher without using the actual implementation of the repository used in production. 18 | // This is another big win because this way we can have test such as the following ones which doesn't actually go to the database in order to retrieve the system users. 19 | // This has a huge impact in terms of the time to wait until all of our test suite is being executed (quicker feedback loop for developers 💪). 20 | // 👍 Win: We can reuse the test environment repository using test doubles. See CodelyTvStaffUsersRepository for its particularities 21 | UsersRepository codelyTvStaffUsersRepository = new CodelyTvStaffUsersRepository(); 22 | UserSearcher userSearcher = new UserSearcher(codelyTvStaffUsersRepository); 23 | 24 | Optional expectedUser = Optional.of(UserMother.rafa()); 25 | 26 | assertEquals(expectedUser, userSearcher.search(UserMother.RAFA_ID)); 27 | } 28 | 29 | @Test 30 | void not_find_non_existing_users() { 31 | // 👍 Win: Our test are far more readable because they doesn't have to deal with the internal implementation of the UserRepository. 32 | // The test is 100% focused on orchestrating the Arrange/Act/Assert or Given/When/Then flow. 33 | // More info: http://wiki.c2.com/?ArrangeActAssert and https://www.martinfowler.com/bliki/GivenWhenThen.html 34 | UsersRepository emptyUsersRepository = new EmptyUsersRepository(); 35 | UserSearcher userSearcher = new UserSearcher(emptyUsersRepository); 36 | 37 | Integer nonExistingUserId = 1; 38 | Optional expectedEmptyResult = Optional.empty(); 39 | 40 | assertEquals(expectedEmptyResult, userSearcher.search(nonExistingUserId)); 41 | } 42 | } 43 | -------------------------------------------------------------------------------- /src/test/java/tv/codely/solid_principles/liskov_substitution_principle/RectangleShould.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.liskov_substitution_principle; 2 | 3 | import org.junit.jupiter.api.Test; 4 | 5 | import static org.junit.jupiter.api.Assertions.assertEquals; 6 | 7 | final class RectangleShould { 8 | @Test 9 | void calculate_its_area() { 10 | Integer rectangleLength = 2; 11 | Integer rectangleWidth = 2; 12 | Rectangle rectangle = new Rectangle(rectangleLength, rectangleWidth); 13 | 14 | Integer expectedArea = 4; 15 | 16 | assertEquals(expectedArea, rectangle.getArea()); 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /src/test/java/tv/codely/solid_principles/liskov_substitution_principle/SquareShould.java: -------------------------------------------------------------------------------- 1 | package tv.codely.solid_principles.liskov_substitution_principle; 2 | 3 | import org.junit.jupiter.api.Test; 4 | 5 | import static org.junit.jupiter.api.Assertions.assertNotEquals; 6 | 7 | final class SquareShould { 8 | @Test 9 | void not_respect_the_liskov_substitution_principle_breaking_the_rectangle_laws_while_modifying_its_length() { 10 | Integer squareLengthAndWidth = 2; 11 | Square square = new Square(squareLengthAndWidth); 12 | 13 | Integer newSquareLength = 4; 14 | square.setLength(newSquareLength); 15 | 16 | Integer expectedAreaTakingIntoAccountRectangleLaws = 8; 17 | 18 | assertNotEquals(expectedAreaTakingIntoAccountRectangleLaws, square.getArea()); 19 | } 20 | } 21 | -------------------------------------------------------------------------------- /src/test/resources/log4j2.properties: -------------------------------------------------------------------------------- 1 | name = CodelyTvJavaSolidExamples 2 | property.filename = logs 3 | appenders = console, file 4 | 5 | status = warn 6 | 7 | appender.console.name = CONSOLE 8 | appender.console.type = CONSOLE 9 | appender.console.target = SYSTEM_OUT 10 | 11 | appender.console.layout.type = PatternLayout 12 | appender.console.layout.pattern = [%level] [%date{HH:mm:ss.SSS}] [%class{0}#%method:%line] %message \(%mdc\) %n%throwable 13 | appender.console.filter.threshold.type = ThresholdFilter 14 | appender.console.filter.threshold.level = info 15 | 16 | appender.file.type = File 17 | appender.file.name = LOGFILE 18 | appender.file.fileName=var/log/java-solid-examples-test.log 19 | appender.file.logstash.type=LogstashLayout 20 | appender.file.logstash.dateTimeFormatPattern = yyyy-MM-dd'T'HH:mm:ss.SSSZZZ 21 | appender.file.logstash.eventTemplateUri = classpath:LogstashJsonEventLayoutV1.json 22 | appender.file.logstash.prettyPrintEnabled = false 23 | appender.file.logstash.stackTraceEnabled = true 24 | 25 | loggers = file 26 | logger.file.name = tv.codely.solid_principles 27 | logger.file.level = info 28 | logger.file.appenderRefs = file 29 | logger.file.appenderRef.file.ref = LOGFILE 30 | 31 | rootLogger.level = info 32 | rootLogger.appenderRefs = stdout 33 | rootLogger.appenderRef.stdout.ref = CONSOLE 34 | -------------------------------------------------------------------------------- /var/log/.gitkeep: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/CodelyTV/java-solid-examples/44600ce024ef957a05e0c4fbe9a76b283b0f84a1/var/log/.gitkeep --------------------------------------------------------------------------------