├── .gitignore ├── .mvn └── wrapper │ ├── MavenWrapperDownloader.java │ ├── maven-wrapper.jar │ └── maven-wrapper.properties ├── README.md ├── mvnw ├── mvnw.cmd ├── pom.xml └── src ├── main ├── java │ └── com │ │ └── mbcoder │ │ └── scheduler │ │ ├── SchedulerApplication.java │ │ ├── controller │ │ └── SchedulingController.java │ │ ├── model │ │ └── ConfigItem.java │ │ ├── repository │ │ └── ConfigRepo.java │ │ └── service │ │ ├── AnnotationScheduler.java │ │ ├── CancellableScheduler.java │ │ ├── DynamicScheduler.java │ │ ├── ExactDateScheduler.java │ │ └── ExternalScheduler.java └── resources │ └── application.properties └── test └── java └── com └── mbcoder └── scheduler └── SchedulerApplicationTests.java /.gitignore: -------------------------------------------------------------------------------- 1 | HELP.md 2 | /target/ 3 | !.mvn/wrapper/maven-wrapper.jar 4 | 5 | ### STS ### 6 | .apt_generated 7 | .classpath 8 | .factorypath 9 | .project 10 | .settings 11 | .springBeans 12 | .sts4-cache 13 | 14 | ### IntelliJ IDEA ### 15 | .idea 16 | *.iws 17 | *.iml 18 | *.ipr 19 | 20 | ### NetBeans ### 21 | /nbproject/private/ 22 | /nbbuild/ 23 | /dist/ 24 | /nbdist/ 25 | /.nb-gradle/ 26 | /build/ 27 | 28 | ### VS Code ### 29 | .vscode/ 30 | -------------------------------------------------------------------------------- /.mvn/wrapper/MavenWrapperDownloader.java: -------------------------------------------------------------------------------- 1 | /* 2 | Licensed to the Apache Software Foundation (ASF) under one 3 | or more contributor license agreements. See the NOTICE file 4 | distributed with this work for additional information 5 | regarding copyright ownership. The ASF licenses this file 6 | to you under the Apache License, Version 2.0 (the 7 | "License"); you may not use this file except in compliance 8 | with the License. You may obtain a copy of the License at 9 | 10 | https://www.apache.org/licenses/LICENSE-2.0 11 | 12 | Unless required by applicable law or agreed to in writing, 13 | software distributed under the License is distributed on an 14 | "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 | KIND, either express or implied. See the License for the 16 | specific language governing permissions and limitations 17 | under the License. 18 | */ 19 | 20 | import java.io.File; 21 | import java.io.FileInputStream; 22 | import java.io.FileOutputStream; 23 | import java.io.IOException; 24 | import java.net.URL; 25 | import java.nio.channels.Channels; 26 | import java.nio.channels.ReadableByteChannel; 27 | import java.util.Properties; 28 | 29 | public class MavenWrapperDownloader { 30 | 31 | /** 32 | * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided. 33 | */ 34 | private static final String DEFAULT_DOWNLOAD_URL = 35 | "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.4.2/maven-wrapper-0.4.2.jar"; 36 | 37 | /** 38 | * Path to the maven-wrapper.properties file, which might contain a downloadUrl property to 39 | * use instead of the default one. 40 | */ 41 | private static final String MAVEN_WRAPPER_PROPERTIES_PATH = 42 | ".mvn/wrapper/maven-wrapper.properties"; 43 | 44 | /** 45 | * Path where the maven-wrapper.jar will be saved to. 46 | */ 47 | private static final String MAVEN_WRAPPER_JAR_PATH = 48 | ".mvn/wrapper/maven-wrapper.jar"; 49 | 50 | /** 51 | * Name of the property which should be used to override the default download url for the wrapper. 52 | */ 53 | private static final String PROPERTY_NAME_WRAPPER_URL = "wrapperUrl"; 54 | 55 | public static void main(String args[]) { 56 | System.out.println("- Downloader started"); 57 | File baseDirectory = new File(args[0]); 58 | System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath()); 59 | 60 | // If the maven-wrapper.properties exists, read it and check if it contains a custom 61 | // wrapperUrl parameter. 62 | File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH); 63 | String url = DEFAULT_DOWNLOAD_URL; 64 | if (mavenWrapperPropertyFile.exists()) { 65 | FileInputStream mavenWrapperPropertyFileInputStream = null; 66 | try { 67 | mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile); 68 | Properties mavenWrapperProperties = new Properties(); 69 | mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream); 70 | url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url); 71 | } catch (IOException e) { 72 | System.out.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'"); 73 | } finally { 74 | try { 75 | if (mavenWrapperPropertyFileInputStream != null) { 76 | mavenWrapperPropertyFileInputStream.close(); 77 | } 78 | } catch (IOException e) { 79 | // Ignore ... 80 | } 81 | } 82 | } 83 | System.out.println("- Downloading from: : " + url); 84 | 85 | File outputFile = new File(baseDirectory.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH); 86 | if (!outputFile.getParentFile().exists()) { 87 | if (!outputFile.getParentFile().mkdirs()) { 88 | System.out.println( 89 | "- ERROR creating output direcrory '" + outputFile.getParentFile().getAbsolutePath() + "'"); 90 | } 91 | } 92 | System.out.println("- Downloading to: " + outputFile.getAbsolutePath()); 93 | try { 94 | downloadFileFromURL(url, outputFile); 95 | System.out.println("Done"); 96 | System.exit(0); 97 | } catch (Throwable e) { 98 | System.out.println("- Error downloading"); 99 | e.printStackTrace(); 100 | System.exit(1); 101 | } 102 | } 103 | 104 | private static void downloadFileFromURL(String urlString, File destination) throws Exception { 105 | URL website = new URL(urlString); 106 | ReadableByteChannel rbc; 107 | rbc = Channels.newChannel(website.openStream()); 108 | FileOutputStream fos = new FileOutputStream(destination); 109 | fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE); 110 | fos.close(); 111 | rbc.close(); 112 | } 113 | 114 | } 115 | -------------------------------------------------------------------------------- /.mvn/wrapper/maven-wrapper.jar: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/mustafabayar/java-dynamic-scheduling-tutorial/959a4da08e4982acc9c1089e658580f1c0a91908/.mvn/wrapper/maven-wrapper.jar -------------------------------------------------------------------------------- /.mvn/wrapper/maven-wrapper.properties: -------------------------------------------------------------------------------- 1 | distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.6.0/apache-maven-3.6.0-bin.zip 2 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # Java Dynamic Scheduling Tutorial 2 | 3 | SpringBoot has @Scheduled annotation for scheduling tasks. But it only works with fixed rates. 4 | In this tutorial I tried to show how to create our own scheduler for dynamic scheduling. 5 | 6 | # Breakdown of Services 7 | 8 | ## AnnotationScheduler 9 | This service shows how to use Spring's own scheduler with a fixed rate or cron expression. 10 | 11 | ## DynamicScheduler 12 | This service shows how to create our own scheduler and make it work with dynamic rates. In this service we can see how to use a value from database as our next execution time. We can also see using different approaches within the same scheduler such as using fixed values, dynamic values, cron expression etc. 13 | 14 | ## CancellableScheduler 15 | Same as dynamic scheduler but on top of that we can now cancel and re-activate the scheduler on demand. 16 | 17 | ## ExactDateScheduler 18 | In this service we see how to create a scheduler to schedule a job to be executed at an exact date instead of giving a rate. 19 | 20 | ## ExternalScheduler 21 | This is advanced version of cancellable scheduler and it is more like a production ready version. With this we can now easily add or remove jobs from other classes. As an example, SchedulingController shows how adding and removing job works from outside. 22 | 23 | - - - 24 | 25 | ### Disclaimer 26 | All the above classes are to demonstrate different possibilities of custom schedulers. You can combine those functionalities in your own scheduler according to your needs. This code is written only for demonstration purposes and is not ready for production, use with caution! 27 | -------------------------------------------------------------------------------- /mvnw: -------------------------------------------------------------------------------- 1 | #!/bin/sh 2 | # ---------------------------------------------------------------------------- 3 | # Licensed to the Apache Software Foundation (ASF) under one 4 | # or more contributor license agreements. See the NOTICE file 5 | # distributed with this work for additional information 6 | # regarding copyright ownership. The ASF licenses this file 7 | # to you under the Apache License, Version 2.0 (the 8 | # "License"); you may not use this file except in compliance 9 | # with the License. You may obtain a copy of the License at 10 | # 11 | # https://www.apache.org/licenses/LICENSE-2.0 12 | # 13 | # Unless required by applicable law or agreed to in writing, 14 | # software distributed under the License is distributed on an 15 | # "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16 | # KIND, either express or implied. See the License for the 17 | # specific language governing permissions and limitations 18 | # under the License. 19 | # ---------------------------------------------------------------------------- 20 | 21 | # ---------------------------------------------------------------------------- 22 | # Maven2 Start Up Batch script 23 | # 24 | # Required ENV vars: 25 | # ------------------ 26 | # JAVA_HOME - location of a JDK home dir 27 | # 28 | # Optional ENV vars 29 | # ----------------- 30 | # M2_HOME - location of maven2's installed home dir 31 | # MAVEN_OPTS - parameters passed to the Java VM when running Maven 32 | # e.g. to debug Maven itself, use 33 | # set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000 34 | # MAVEN_SKIP_RC - flag to disable loading of mavenrc files 35 | # ---------------------------------------------------------------------------- 36 | 37 | if [ -z "$MAVEN_SKIP_RC" ] ; then 38 | 39 | if [ -f /etc/mavenrc ] ; then 40 | . /etc/mavenrc 41 | fi 42 | 43 | if [ -f "$HOME/.mavenrc" ] ; then 44 | . "$HOME/.mavenrc" 45 | fi 46 | 47 | fi 48 | 49 | # OS specific support. $var _must_ be set to either true or false. 50 | cygwin=false; 51 | darwin=false; 52 | mingw=false 53 | case "`uname`" in 54 | CYGWIN*) cygwin=true ;; 55 | MINGW*) mingw=true;; 56 | Darwin*) darwin=true 57 | # Use /usr/libexec/java_home if available, otherwise fall back to /Library/Java/Home 58 | # See https://developer.apple.com/library/mac/qa/qa1170/_index.html 59 | if [ -z "$JAVA_HOME" ]; then 60 | if [ -x "/usr/libexec/java_home" ]; then 61 | export JAVA_HOME="`/usr/libexec/java_home`" 62 | else 63 | export JAVA_HOME="/Library/Java/Home" 64 | fi 65 | fi 66 | ;; 67 | esac 68 | 69 | if [ -z "$JAVA_HOME" ] ; then 70 | if [ -r /etc/gentoo-release ] ; then 71 | JAVA_HOME=`java-config --jre-home` 72 | fi 73 | fi 74 | 75 | if [ -z "$M2_HOME" ] ; then 76 | ## resolve links - $0 may be a link to maven's home 77 | PRG="$0" 78 | 79 | # need this for relative symlinks 80 | while [ -h "$PRG" ] ; do 81 | ls=`ls -ld "$PRG"` 82 | link=`expr "$ls" : '.*-> \(.*\)$'` 83 | if expr "$link" : '/.*' > /dev/null; then 84 | PRG="$link" 85 | else 86 | PRG="`dirname "$PRG"`/$link" 87 | fi 88 | done 89 | 90 | saveddir=`pwd` 91 | 92 | M2_HOME=`dirname "$PRG"`/.. 93 | 94 | # make it fully qualified 95 | M2_HOME=`cd "$M2_HOME" && pwd` 96 | 97 | cd "$saveddir" 98 | # echo Using m2 at $M2_HOME 99 | fi 100 | 101 | # For Cygwin, ensure paths are in UNIX format before anything is touched 102 | if $cygwin ; then 103 | [ -n "$M2_HOME" ] && 104 | M2_HOME=`cygpath --unix "$M2_HOME"` 105 | [ -n "$JAVA_HOME" ] && 106 | JAVA_HOME=`cygpath --unix "$JAVA_HOME"` 107 | [ -n "$CLASSPATH" ] && 108 | CLASSPATH=`cygpath --path --unix "$CLASSPATH"` 109 | fi 110 | 111 | # For Mingw, ensure paths are in UNIX format before anything is touched 112 | if $mingw ; then 113 | [ -n "$M2_HOME" ] && 114 | M2_HOME="`(cd "$M2_HOME"; pwd)`" 115 | [ -n "$JAVA_HOME" ] && 116 | JAVA_HOME="`(cd "$JAVA_HOME"; pwd)`" 117 | # TODO classpath? 118 | fi 119 | 120 | if [ -z "$JAVA_HOME" ]; then 121 | javaExecutable="`which javac`" 122 | if [ -n "$javaExecutable" ] && ! [ "`expr \"$javaExecutable\" : '\([^ ]*\)'`" = "no" ]; then 123 | # readlink(1) is not available as standard on Solaris 10. 124 | readLink=`which readlink` 125 | if [ ! `expr "$readLink" : '\([^ ]*\)'` = "no" ]; then 126 | if $darwin ; then 127 | javaHome="`dirname \"$javaExecutable\"`" 128 | javaExecutable="`cd \"$javaHome\" && pwd -P`/javac" 129 | else 130 | javaExecutable="`readlink -f \"$javaExecutable\"`" 131 | fi 132 | javaHome="`dirname \"$javaExecutable\"`" 133 | javaHome=`expr "$javaHome" : '\(.*\)/bin'` 134 | JAVA_HOME="$javaHome" 135 | export JAVA_HOME 136 | fi 137 | fi 138 | fi 139 | 140 | if [ -z "$JAVACMD" ] ; then 141 | if [ -n "$JAVA_HOME" ] ; then 142 | if [ -x "$JAVA_HOME/jre/sh/java" ] ; then 143 | # IBM's JDK on AIX uses strange locations for the executables 144 | JAVACMD="$JAVA_HOME/jre/sh/java" 145 | else 146 | JAVACMD="$JAVA_HOME/bin/java" 147 | fi 148 | else 149 | JAVACMD="`which java`" 150 | fi 151 | fi 152 | 153 | if [ ! -x "$JAVACMD" ] ; then 154 | echo "Error: JAVA_HOME is not defined correctly." >&2 155 | echo " We cannot execute $JAVACMD" >&2 156 | exit 1 157 | fi 158 | 159 | if [ -z "$JAVA_HOME" ] ; then 160 | echo "Warning: JAVA_HOME environment variable is not set." 161 | fi 162 | 163 | CLASSWORLDS_LAUNCHER=org.codehaus.plexus.classworlds.launcher.Launcher 164 | 165 | # traverses directory structure from process work directory to filesystem root 166 | # first directory with .mvn subdirectory is considered project base directory 167 | find_maven_basedir() { 168 | 169 | if [ -z "$1" ] 170 | then 171 | echo "Path not specified to find_maven_basedir" 172 | return 1 173 | fi 174 | 175 | basedir="$1" 176 | wdir="$1" 177 | while [ "$wdir" != '/' ] ; do 178 | if [ -d "$wdir"/.mvn ] ; then 179 | basedir=$wdir 180 | break 181 | fi 182 | # workaround for JBEAP-8937 (on Solaris 10/Sparc) 183 | if [ -d "${wdir}" ]; then 184 | wdir=`cd "$wdir/.."; pwd` 185 | fi 186 | # end of workaround 187 | done 188 | echo "${basedir}" 189 | } 190 | 191 | # concatenates all lines of a file 192 | concat_lines() { 193 | if [ -f "$1" ]; then 194 | echo "$(tr -s '\n' ' ' < "$1")" 195 | fi 196 | } 197 | 198 | BASE_DIR=`find_maven_basedir "$(pwd)"` 199 | if [ -z "$BASE_DIR" ]; then 200 | exit 1; 201 | fi 202 | 203 | ########################################################################################## 204 | # Extension to allow automatically downloading the maven-wrapper.jar from Maven-central 205 | # This allows using the maven wrapper in projects that prohibit checking in binary data. 206 | ########################################################################################## 207 | if [ -r "$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" ]; then 208 | if [ "$MVNW_VERBOSE" = true ]; then 209 | echo "Found .mvn/wrapper/maven-wrapper.jar" 210 | fi 211 | else 212 | if [ "$MVNW_VERBOSE" = true ]; then 213 | echo "Couldn't find .mvn/wrapper/maven-wrapper.jar, downloading it ..." 214 | fi 215 | jarUrl="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.4.2/maven-wrapper-0.4.2.jar" 216 | while IFS="=" read key value; do 217 | case "$key" in (wrapperUrl) jarUrl="$value"; break ;; 218 | esac 219 | done < "$BASE_DIR/.mvn/wrapper/maven-wrapper.properties" 220 | if [ "$MVNW_VERBOSE" = true ]; then 221 | echo "Downloading from: $jarUrl" 222 | fi 223 | wrapperJarPath="$BASE_DIR/.mvn/wrapper/maven-wrapper.jar" 224 | 225 | if command -v wget > /dev/null; then 226 | if [ "$MVNW_VERBOSE" = true ]; then 227 | echo "Found wget ... using wget" 228 | fi 229 | wget "$jarUrl" -O "$wrapperJarPath" 230 | elif command -v curl > /dev/null; then 231 | if [ "$MVNW_VERBOSE" = true ]; then 232 | echo "Found curl ... using curl" 233 | fi 234 | curl -o "$wrapperJarPath" "$jarUrl" 235 | else 236 | if [ "$MVNW_VERBOSE" = true ]; then 237 | echo "Falling back to using Java to download" 238 | fi 239 | javaClass="$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.java" 240 | if [ -e "$javaClass" ]; then 241 | if [ ! -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then 242 | if [ "$MVNW_VERBOSE" = true ]; then 243 | echo " - Compiling MavenWrapperDownloader.java ..." 244 | fi 245 | # Compiling the Java class 246 | ("$JAVA_HOME/bin/javac" "$javaClass") 247 | fi 248 | if [ -e "$BASE_DIR/.mvn/wrapper/MavenWrapperDownloader.class" ]; then 249 | # Running the downloader 250 | if [ "$MVNW_VERBOSE" = true ]; then 251 | echo " - Running MavenWrapperDownloader.java ..." 252 | fi 253 | ("$JAVA_HOME/bin/java" -cp .mvn/wrapper MavenWrapperDownloader "$MAVEN_PROJECTBASEDIR") 254 | fi 255 | fi 256 | fi 257 | fi 258 | ########################################################################################## 259 | # End of extension 260 | ########################################################################################## 261 | 262 | export MAVEN_PROJECTBASEDIR=${MAVEN_BASEDIR:-"$BASE_DIR"} 263 | if [ "$MVNW_VERBOSE" = true ]; then 264 | echo $MAVEN_PROJECTBASEDIR 265 | fi 266 | MAVEN_OPTS="$(concat_lines "$MAVEN_PROJECTBASEDIR/.mvn/jvm.config") $MAVEN_OPTS" 267 | 268 | # For Cygwin, switch paths to Windows format before running java 269 | if $cygwin; then 270 | [ -n "$M2_HOME" ] && 271 | M2_HOME=`cygpath --path --windows "$M2_HOME"` 272 | [ -n "$JAVA_HOME" ] && 273 | JAVA_HOME=`cygpath --path --windows "$JAVA_HOME"` 274 | [ -n "$CLASSPATH" ] && 275 | CLASSPATH=`cygpath --path --windows "$CLASSPATH"` 276 | [ -n "$MAVEN_PROJECTBASEDIR" ] && 277 | MAVEN_PROJECTBASEDIR=`cygpath --path --windows "$MAVEN_PROJECTBASEDIR"` 278 | fi 279 | 280 | WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain 281 | 282 | exec "$JAVACMD" \ 283 | $MAVEN_OPTS \ 284 | -classpath "$MAVEN_PROJECTBASEDIR/.mvn/wrapper/maven-wrapper.jar" \ 285 | "-Dmaven.home=${M2_HOME}" "-Dmaven.multiModuleProjectDirectory=${MAVEN_PROJECTBASEDIR}" \ 286 | ${WRAPPER_LAUNCHER} $MAVEN_CONFIG "$@" 287 | -------------------------------------------------------------------------------- /mvnw.cmd: -------------------------------------------------------------------------------- 1 | @REM ---------------------------------------------------------------------------- 2 | @REM Licensed to the Apache Software Foundation (ASF) under one 3 | @REM or more contributor license agreements. See the NOTICE file 4 | @REM distributed with this work for additional information 5 | @REM regarding copyright ownership. The ASF licenses this file 6 | @REM to you under the Apache License, Version 2.0 (the 7 | @REM "License"); you may not use this file except in compliance 8 | @REM with the License. You may obtain a copy of the License at 9 | @REM 10 | @REM https://www.apache.org/licenses/LICENSE-2.0 11 | @REM 12 | @REM Unless required by applicable law or agreed to in writing, 13 | @REM software distributed under the License is distributed on an 14 | @REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 | @REM KIND, either express or implied. See the License for the 16 | @REM specific language governing permissions and limitations 17 | @REM under the License. 18 | @REM ---------------------------------------------------------------------------- 19 | 20 | @REM ---------------------------------------------------------------------------- 21 | @REM Maven2 Start Up Batch script 22 | @REM 23 | @REM Required ENV vars: 24 | @REM JAVA_HOME - location of a JDK home dir 25 | @REM 26 | @REM Optional ENV vars 27 | @REM M2_HOME - location of maven2's installed home dir 28 | @REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands 29 | @REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a key stroke before ending 30 | @REM MAVEN_OPTS - parameters passed to the Java VM when running Maven 31 | @REM e.g. to debug Maven itself, use 32 | @REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000 33 | @REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files 34 | @REM ---------------------------------------------------------------------------- 35 | 36 | @REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on' 37 | @echo off 38 | @REM set title of command window 39 | title %0 40 | @REM enable echoing my setting MAVEN_BATCH_ECHO to 'on' 41 | @if "%MAVEN_BATCH_ECHO%" == "on" echo %MAVEN_BATCH_ECHO% 42 | 43 | @REM set %HOME% to equivalent of $HOME 44 | if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%") 45 | 46 | @REM Execute a user defined script before this one 47 | if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre 48 | @REM check for pre script, once with legacy .bat ending and once with .cmd ending 49 | if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat" 50 | if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd" 51 | :skipRcPre 52 | 53 | @setlocal 54 | 55 | set ERROR_CODE=0 56 | 57 | @REM To isolate internal variables from possible post scripts, we use another setlocal 58 | @setlocal 59 | 60 | @REM ==== START VALIDATION ==== 61 | if not "%JAVA_HOME%" == "" goto OkJHome 62 | 63 | echo. 64 | echo Error: JAVA_HOME not found in your environment. >&2 65 | echo Please set the JAVA_HOME variable in your environment to match the >&2 66 | echo location of your Java installation. >&2 67 | echo. 68 | goto error 69 | 70 | :OkJHome 71 | if exist "%JAVA_HOME%\bin\java.exe" goto init 72 | 73 | echo. 74 | echo Error: JAVA_HOME is set to an invalid directory. >&2 75 | echo JAVA_HOME = "%JAVA_HOME%" >&2 76 | echo Please set the JAVA_HOME variable in your environment to match the >&2 77 | echo location of your Java installation. >&2 78 | echo. 79 | goto error 80 | 81 | @REM ==== END VALIDATION ==== 82 | 83 | :init 84 | 85 | @REM Find the project base dir, i.e. the directory that contains the folder ".mvn". 86 | @REM Fallback to current working directory if not found. 87 | 88 | set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR% 89 | IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir 90 | 91 | set EXEC_DIR=%CD% 92 | set WDIR=%EXEC_DIR% 93 | :findBaseDir 94 | IF EXIST "%WDIR%"\.mvn goto baseDirFound 95 | cd .. 96 | IF "%WDIR%"=="%CD%" goto baseDirNotFound 97 | set WDIR=%CD% 98 | goto findBaseDir 99 | 100 | :baseDirFound 101 | set MAVEN_PROJECTBASEDIR=%WDIR% 102 | cd "%EXEC_DIR%" 103 | goto endDetectBaseDir 104 | 105 | :baseDirNotFound 106 | set MAVEN_PROJECTBASEDIR=%EXEC_DIR% 107 | cd "%EXEC_DIR%" 108 | 109 | :endDetectBaseDir 110 | 111 | IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig 112 | 113 | @setlocal EnableExtensions EnableDelayedExpansion 114 | for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a 115 | @endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS% 116 | 117 | :endReadAdditionalConfig 118 | 119 | SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe" 120 | set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar" 121 | set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain 122 | 123 | set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.4.2/maven-wrapper-0.4.2.jar" 124 | FOR /F "tokens=1,2 delims==" %%A IN (%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties) DO ( 125 | IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B 126 | ) 127 | 128 | @REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central 129 | @REM This allows using the maven wrapper in projects that prohibit checking in binary data. 130 | if exist %WRAPPER_JAR% ( 131 | echo Found %WRAPPER_JAR% 132 | ) else ( 133 | echo Couldn't find %WRAPPER_JAR%, downloading it ... 134 | echo Downloading from: %DOWNLOAD_URL% 135 | powershell -Command "(New-Object Net.WebClient).DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')" 136 | echo Finished downloading %WRAPPER_JAR% 137 | ) 138 | @REM End of extension 139 | 140 | %MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %* 141 | if ERRORLEVEL 1 goto error 142 | goto end 143 | 144 | :error 145 | set ERROR_CODE=1 146 | 147 | :end 148 | @endlocal & set ERROR_CODE=%ERROR_CODE% 149 | 150 | if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost 151 | @REM check for post script, once with legacy .bat ending and once with .cmd ending 152 | if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat" 153 | if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd" 154 | :skipRcPost 155 | 156 | @REM pause the script if MAVEN_BATCH_PAUSE is set to 'on' 157 | if "%MAVEN_BATCH_PAUSE%" == "on" pause 158 | 159 | if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE% 160 | 161 | exit /B %ERROR_CODE% 162 | -------------------------------------------------------------------------------- /pom.xml: -------------------------------------------------------------------------------- 1 | 2 | 4 | 4.0.0 5 | 6 | org.springframework.boot 7 | spring-boot-starter-parent 8 | 2.1.5.RELEASE 9 | 10 | 11 | com.mbcoder 12 | scheduler 13 | 0.0.1-SNAPSHOT 14 | scheduler 15 | Demo project for Spring Boot 16 | 17 | 18 | 1.8 19 | 20 | 21 | 22 | 23 | org.springframework.boot 24 | spring-boot-starter 25 | 26 | 27 | 28 | org.springframework.boot 29 | spring-boot-starter-web 30 | 31 | 32 | 33 | org.springframework.boot 34 | spring-boot-starter-test 35 | test 36 | 37 | 38 | 39 | org.springframework.boot 40 | spring-boot-starter-data-jpa 41 | 42 | 43 | 44 | com.h2database 45 | h2 46 | runtime 47 | 48 | 49 | 50 | 51 | 52 | 53 | org.springframework.boot 54 | spring-boot-maven-plugin 55 | 56 | 57 | 58 | 59 | 60 | -------------------------------------------------------------------------------- /src/main/java/com/mbcoder/scheduler/SchedulerApplication.java: -------------------------------------------------------------------------------- 1 | package com.mbcoder.scheduler; 2 | 3 | import org.springframework.boot.SpringApplication; 4 | import org.springframework.boot.autoconfigure.SpringBootApplication; 5 | 6 | @SpringBootApplication 7 | public class SchedulerApplication { 8 | 9 | public static void main(String[] args) { 10 | SpringApplication.run(SchedulerApplication.class, args); 11 | } 12 | 13 | } 14 | -------------------------------------------------------------------------------- /src/main/java/com/mbcoder/scheduler/controller/SchedulingController.java: -------------------------------------------------------------------------------- 1 | package com.mbcoder.scheduler.controller; 2 | 3 | import com.mbcoder.scheduler.service.ExternalScheduler; 4 | import org.springframework.beans.factory.annotation.Autowired; 5 | import org.springframework.web.bind.annotation.*; 6 | 7 | // This is a very basic controller just to show how scheduler can be called from outside, 8 | // this is not a good exemplary controller and endpoints are not well designed 9 | @RestController 10 | public class SchedulingController { 11 | 12 | @Autowired 13 | ExternalScheduler externalScheduler; 14 | 15 | @PostMapping("/scheduler/add") 16 | @ResponseBody 17 | public String addJob(@RequestParam String name) { 18 | boolean result = externalScheduler.addJob(name); 19 | if (result) { 20 | return "Job successfully scheduled!"; 21 | } 22 | return "There is already a job running for the specified name!"; 23 | } 24 | 25 | @PostMapping("/scheduler/remove") 26 | @ResponseBody 27 | public String removeJob(@RequestParam String name) { 28 | boolean result = externalScheduler.removeJob(name); 29 | if (result) { 30 | return "Job successfully removed!"; 31 | } 32 | return "There is no such job running!"; 33 | } 34 | } 35 | -------------------------------------------------------------------------------- /src/main/java/com/mbcoder/scheduler/model/ConfigItem.java: -------------------------------------------------------------------------------- 1 | package com.mbcoder.scheduler.model; 2 | 3 | import javax.persistence.Entity; 4 | import javax.persistence.Id; 5 | 6 | @Entity 7 | public class ConfigItem { 8 | 9 | @Id 10 | String configKey; 11 | 12 | String configValue; 13 | 14 | public ConfigItem() { 15 | } 16 | 17 | public ConfigItem(String configKey, String configValue) { 18 | this.configKey = configKey; 19 | this.configValue = configValue; 20 | } 21 | 22 | public String getConfigKey() { 23 | return configKey; 24 | } 25 | 26 | public void setConfigKey(String configKey) { 27 | this.configKey = configKey; 28 | } 29 | 30 | public String getConfigValue() { 31 | return configValue; 32 | } 33 | 34 | public void setConfigValue(String configValue) { 35 | this.configValue = configValue; 36 | } 37 | } 38 | -------------------------------------------------------------------------------- /src/main/java/com/mbcoder/scheduler/repository/ConfigRepo.java: -------------------------------------------------------------------------------- 1 | package com.mbcoder.scheduler.repository; 2 | 3 | import com.mbcoder.scheduler.model.ConfigItem; 4 | import org.springframework.data.jpa.repository.JpaRepository; 5 | 6 | public interface ConfigRepo extends JpaRepository { 7 | } 8 | -------------------------------------------------------------------------------- /src/main/java/com/mbcoder/scheduler/service/AnnotationScheduler.java: -------------------------------------------------------------------------------- 1 | package com.mbcoder.scheduler.service; 2 | 3 | import org.slf4j.Logger; 4 | import org.slf4j.LoggerFactory; 5 | import org.springframework.scheduling.annotation.EnableScheduling; 6 | import org.springframework.scheduling.annotation.Scheduled; 7 | import org.springframework.stereotype.Service; 8 | 9 | @EnableScheduling 10 | @Service 11 | public class AnnotationScheduler { 12 | 13 | private static Logger LOGGER = LoggerFactory.getLogger(AnnotationScheduler.class); 14 | 15 | // @Scheduled annotation always works with fixed rates and can not be changed after started. 16 | // Also @EnableScheduling annotation must be used to enable this annotation. 17 | // Using @EnableScheduling in any class is enough for enabling it for the whole project. 18 | @Scheduled(fixedRate = 5000, initialDelay = 10000) 19 | public void printFixedRate() { 20 | LOGGER.info("printFixedRate: Print every 5 seconds with one time initial delay of 10 seconds"); 21 | } 22 | 23 | @Scheduled(cron = "0/10 * * * * ?") 24 | public void printCron() { 25 | LOGGER.info("printCron: Print every 10 seconds with cron"); 26 | } 27 | } 28 | -------------------------------------------------------------------------------- /src/main/java/com/mbcoder/scheduler/service/CancellableScheduler.java: -------------------------------------------------------------------------------- 1 | package com.mbcoder.scheduler.service; 2 | 3 | import org.slf4j.Logger; 4 | import org.slf4j.LoggerFactory; 5 | import org.springframework.context.annotation.Bean; 6 | import org.springframework.scheduling.TaskScheduler; 7 | import org.springframework.scheduling.annotation.SchedulingConfigurer; 8 | import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler; 9 | import org.springframework.scheduling.config.ScheduledTaskRegistrar; 10 | import org.springframework.scheduling.support.CronTrigger; 11 | import org.springframework.stereotype.Service; 12 | 13 | import java.util.*; 14 | import java.util.concurrent.ScheduledFuture; 15 | 16 | /** 17 | * Alternative version for DynamicScheduler 18 | * This one should support everything the basic dynamic scheduler does, 19 | * and on top of it, you can cancel and re-activate the scheduler. 20 | * 21 | * Also nothing here is set in stone, you can change the implementation depending on your needs, 22 | * this is just an example about how to cancel and re-activate 23 | */ 24 | @Service 25 | public class CancellableScheduler implements SchedulingConfigurer { 26 | 27 | private static Logger LOGGER = LoggerFactory.getLogger(CancellableScheduler.class); 28 | 29 | ScheduledTaskRegistrar scheduledTaskRegistrar; 30 | 31 | ScheduledFuture future1; 32 | ScheduledFuture future2; 33 | ScheduledFuture future3; 34 | Map futureMap = new HashMap<>(); 35 | 36 | @Bean 37 | public TaskScheduler poolScheduler2() { 38 | ThreadPoolTaskScheduler scheduler = new ThreadPoolTaskScheduler(); 39 | scheduler.setThreadNamePrefix("ThreadPoolTaskScheduler"); 40 | scheduler.setPoolSize(1); 41 | scheduler.initialize(); 42 | return scheduler; 43 | } 44 | 45 | // We can have multiple tasks inside the same registrar as we can see below. 46 | @Override 47 | public void configureTasks(ScheduledTaskRegistrar taskRegistrar) { 48 | if (scheduledTaskRegistrar == null) { 49 | scheduledTaskRegistrar = taskRegistrar; 50 | } 51 | if (taskRegistrar.getScheduler() == null) { 52 | taskRegistrar.setScheduler(poolScheduler2()); 53 | } 54 | 55 | if (future1 == null || (future1.isCancelled() && futureMap.get(future1) == true)) { 56 | future1 = taskRegistrar.getScheduler().schedule(() -> scheduleFixed(5), t -> { 57 | Calendar nextExecutionTime = new GregorianCalendar(); 58 | Date lastActualExecutionTime = t.lastActualExecutionTime(); 59 | nextExecutionTime.setTime(lastActualExecutionTime != null ? lastActualExecutionTime : new Date()); 60 | nextExecutionTime.add(Calendar.SECOND, 5); 61 | return nextExecutionTime.getTime(); 62 | }); 63 | } 64 | 65 | if (future2 == null || (future2.isCancelled() && futureMap.get(future2) == true)) { 66 | future2 = taskRegistrar.getScheduler().schedule(() -> scheduleFixed(8), t -> { 67 | Calendar nextExecutionTime = new GregorianCalendar(); 68 | Date lastActualExecutionTime = t.lastActualExecutionTime(); 69 | nextExecutionTime.setTime(lastActualExecutionTime != null ? lastActualExecutionTime : new Date()); 70 | nextExecutionTime.add(Calendar.SECOND, 8); 71 | return nextExecutionTime.getTime(); 72 | }); 73 | } 74 | 75 | // Or cron way, you can also get the expression from DB or somewhere else just like we did in DynamicScheduler service. 76 | if (future3 == null || (future3.isCancelled() && futureMap.get(future3) == true)) { 77 | CronTrigger croneTrigger = new CronTrigger("0/10 * * * * ?", TimeZone.getDefault()); 78 | future3 = taskRegistrar.getScheduler().schedule(() -> scheduleCron("0/10 * * * * ?"), croneTrigger); 79 | } 80 | } 81 | 82 | public void scheduleFixed(int frequency) { 83 | LOGGER.info("scheduleFixed: Next execution time of this will always be {} seconds", frequency); 84 | } 85 | 86 | // Only reason this method gets the cron as parameter is for debug purposes. 87 | public void scheduleCron(String cron) { 88 | LOGGER.info("scheduleCron: Next execution time of this taken from cron expression -> {}", cron); 89 | } 90 | 91 | /** 92 | * @param mayInterruptIfRunning {@code true} if the thread executing this task 93 | * should be interrupted; otherwise, in-progress tasks are allowed to complete 94 | */ 95 | public void cancelFuture(boolean mayInterruptIfRunning, ScheduledFuture future) { 96 | LOGGER.info("Cancelling a future"); 97 | future.cancel(mayInterruptIfRunning); // set to false if you want the running task to be completed first. 98 | futureMap.put(future, false); 99 | } 100 | 101 | public void activateFuture(ScheduledFuture future) { 102 | LOGGER.info("Re-Activating a future"); 103 | futureMap.put(future, true); 104 | configureTasks(scheduledTaskRegistrar); 105 | } 106 | 107 | public void cancelAll() { 108 | cancelFuture(true, future1); 109 | cancelFuture(true, future2); 110 | cancelFuture(true, future3); 111 | } 112 | 113 | public void activateAll() { 114 | activateFuture(future1); 115 | activateFuture(future2); 116 | activateFuture(future3); 117 | } 118 | 119 | } 120 | -------------------------------------------------------------------------------- /src/main/java/com/mbcoder/scheduler/service/DynamicScheduler.java: -------------------------------------------------------------------------------- 1 | package com.mbcoder.scheduler.service; 2 | 3 | import com.mbcoder.scheduler.model.ConfigItem; 4 | import com.mbcoder.scheduler.repository.ConfigRepo; 5 | import org.slf4j.Logger; 6 | import org.slf4j.LoggerFactory; 7 | import org.springframework.beans.factory.annotation.Autowired; 8 | import org.springframework.context.annotation.Bean; 9 | import org.springframework.scheduling.TaskScheduler; 10 | import org.springframework.scheduling.annotation.SchedulingConfigurer; 11 | import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler; 12 | import org.springframework.scheduling.config.ScheduledTaskRegistrar; 13 | import org.springframework.scheduling.support.CronTrigger; 14 | import org.springframework.stereotype.Service; 15 | 16 | import javax.annotation.PostConstruct; 17 | import java.util.*; 18 | 19 | @Service 20 | public class DynamicScheduler implements SchedulingConfigurer { 21 | 22 | private static Logger LOGGER = LoggerFactory.getLogger(DynamicScheduler.class); 23 | 24 | @Autowired 25 | ConfigRepo repo; 26 | 27 | @PostConstruct 28 | public void initDatabase() { 29 | ConfigItem config = new ConfigItem("next_exec_time", "4"); 30 | repo.save(config); 31 | } 32 | 33 | @Bean 34 | public TaskScheduler poolScheduler() { 35 | ThreadPoolTaskScheduler scheduler = new ThreadPoolTaskScheduler(); 36 | scheduler.setThreadNamePrefix("ThreadPoolTaskScheduler"); 37 | scheduler.setPoolSize(1); 38 | scheduler.initialize(); 39 | return scheduler; 40 | } 41 | 42 | // We can have multiple tasks inside the same registrar as we can see below. 43 | @Override 44 | public void configureTasks(ScheduledTaskRegistrar taskRegistrar) { 45 | taskRegistrar.setScheduler(poolScheduler()); 46 | 47 | // Random next execution time. 48 | taskRegistrar.addTriggerTask(() -> scheduleDynamically(), t -> { 49 | Calendar nextExecutionTime = new GregorianCalendar(); 50 | Date lastActualExecutionTime = t.lastActualExecutionTime(); 51 | nextExecutionTime.setTime(lastActualExecutionTime != null ? lastActualExecutionTime : new Date()); 52 | nextExecutionTime.add(Calendar.SECOND, getNextExecutionTime()); // This is where we set the next execution time. 53 | return nextExecutionTime.getTime(); 54 | }); 55 | 56 | // Fixed next execution time. 57 | taskRegistrar.addTriggerTask(() -> scheduleFixed(), t -> { 58 | Calendar nextExecutionTime = new GregorianCalendar(); 59 | Date lastActualExecutionTime = t.lastActualExecutionTime(); 60 | nextExecutionTime.setTime(lastActualExecutionTime != null ? lastActualExecutionTime : new Date()); 61 | nextExecutionTime.add(Calendar.SECOND, 7); // This is where we set the next execution time. 62 | return nextExecutionTime.getTime(); 63 | }); 64 | 65 | // Next execution time is taken from DB, so if the value in DB changes, next execution time will change too. 66 | taskRegistrar.addTriggerTask(() -> scheduledDatabase(repo.findById("next_exec_time").get().getConfigValue()), t -> { 67 | Calendar nextExecutionTime = new GregorianCalendar(); 68 | Date lastActualExecutionTime = t.lastActualExecutionTime(); 69 | nextExecutionTime.setTime(lastActualExecutionTime != null ? lastActualExecutionTime : new Date()); 70 | nextExecutionTime.add(Calendar.SECOND, Integer.parseInt(repo.findById("next_exec_time").get().getConfigValue())); 71 | return nextExecutionTime.getTime(); 72 | }); 73 | 74 | // or cron way, you can also get the expression from DB or somewhere else just like we did above. 75 | taskRegistrar.addTriggerTask(() -> scheduleCron(repo.findById("next_exec_time").get().getConfigValue()), t -> { 76 | CronTrigger crontrigger = new CronTrigger(repo.findById("next_exec_time").get().getConfigValue()); 77 | return crontrigger.nextExecutionTime(t); 78 | }); 79 | } 80 | 81 | public void scheduleDynamically() { 82 | LOGGER.info("scheduleDynamically: Next execution time of this changes every time between 1 and 5 seconds"); 83 | } 84 | 85 | // I added this to show that one taskRegistrar can have multiple different tasks. 86 | // And each of those tasks can have their own next execution time. 87 | public void scheduleFixed() { 88 | LOGGER.info("scheduleFixed: Next execution time of this will always be 7 seconds"); 89 | } 90 | 91 | public void scheduledDatabase(String time) { 92 | LOGGER.info("scheduledDatabase: Next execution time of this will be taken from DB -> {}", time); 93 | } 94 | 95 | // Only reason this method gets the cron as parameter is for debug purposes. 96 | public void scheduleCron(String cron) { 97 | LOGGER.info("scheduleCron: Next execution time of this taken from cron expression -> {}", cron); 98 | } 99 | 100 | // This is only to show that next execution time can be changed on the go with SchedulingConfigurer. 101 | // This can not be done via @Scheduled annotation. 102 | public int getNextExecutionTime() { 103 | return new Random().nextInt(5) + 1; 104 | } 105 | 106 | } 107 | -------------------------------------------------------------------------------- /src/main/java/com/mbcoder/scheduler/service/ExactDateScheduler.java: -------------------------------------------------------------------------------- 1 | package com.mbcoder.scheduler.service; 2 | 3 | import org.slf4j.Logger; 4 | import org.slf4j.LoggerFactory; 5 | import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler; 6 | import org.springframework.stereotype.Service; 7 | 8 | import java.time.*; 9 | import java.time.temporal.ChronoUnit; 10 | 11 | @Service 12 | public class ExactDateScheduler { 13 | 14 | private static Logger LOGGER = LoggerFactory.getLogger(ExactDateScheduler.class); 15 | 16 | private ThreadPoolTaskScheduler poolScheduler; 17 | 18 | public ExactDateScheduler() { 19 | poolScheduler = new ThreadPoolTaskScheduler(); 20 | poolScheduler.setThreadNamePrefix("ThreadPoolTaskScheduler"); 21 | poolScheduler.setPoolSize(1); 22 | poolScheduler.initialize(); 23 | LocalDateTime now = LocalDateTime.now(); 24 | } 25 | 26 | public Instant scheduleAt(LocalDateTime time) { 27 | LocalDateTime now = LocalDateTime.now(); 28 | if (time.isBefore(now)) { 29 | throw new IllegalArgumentException("You can not schedule this task as starting date/time is in the past"); 30 | } 31 | 32 | ZoneId zone = ZoneId.of("Europe/Berlin"); 33 | ZoneOffset zoneOffSet = zone.getRules().getOffset(time); 34 | Instant whenToRun = time.toInstant(zoneOffSet); 35 | poolScheduler.schedule(() -> realMethod(), whenToRun); 36 | return whenToRun; 37 | } 38 | 39 | public void scheduleDaily(LocalDateTime startDate, LocalDateTime endDate) { 40 | LocalDateTime now = LocalDateTime.now(); 41 | if (now.isAfter(endDate)) { 42 | LOGGER.info("End date reached, stopping scheduling more tasks."); 43 | return; 44 | } 45 | 46 | // Since we haven't reached the endDate yet, we would be safe to bring startDate to NOW if it was in the past. 47 | // So if we try to start scheduler for 7 days but first 3 days are already in the past, we will run the remaining 4 tasks. 48 | LocalDateTime timeToRun = startDate.isBefore(now) ? now : startDate; 49 | Instant scheduledTime = scheduleAt(timeToRun); 50 | // Basically scheduling this method again so that it enqueues new job 1 day later, until we reach end date. 51 | poolScheduler.schedule(() -> scheduleDaily(startDate, endDate), scheduledTime.plus(1, ChronoUnit.DAYS).minus(5, ChronoUnit.MINUTES)); 52 | } 53 | 54 | public void realMethod() { 55 | LOGGER.info("Running from exact Scheduler"); 56 | } 57 | 58 | } 59 | -------------------------------------------------------------------------------- /src/main/java/com/mbcoder/scheduler/service/ExternalScheduler.java: -------------------------------------------------------------------------------- 1 | package com.mbcoder.scheduler.service; 2 | 3 | import org.slf4j.Logger; 4 | import org.slf4j.LoggerFactory; 5 | import org.springframework.context.annotation.Bean; 6 | import org.springframework.scheduling.TaskScheduler; 7 | import org.springframework.scheduling.annotation.SchedulingConfigurer; 8 | import org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler; 9 | import org.springframework.scheduling.config.ScheduledTaskRegistrar; 10 | import org.springframework.stereotype.Service; 11 | 12 | import java.util.*; 13 | import java.util.concurrent.ScheduledFuture; 14 | 15 | @Service 16 | public class ExternalScheduler implements SchedulingConfigurer { 17 | 18 | private static Logger LOGGER = LoggerFactory.getLogger(ExternalScheduler.class); 19 | 20 | ScheduledTaskRegistrar scheduledTaskRegistrar; 21 | 22 | Map futureMap = new HashMap<>(); 23 | 24 | @Bean 25 | public TaskScheduler poolScheduler() { 26 | ThreadPoolTaskScheduler scheduler = new ThreadPoolTaskScheduler(); 27 | scheduler.setThreadNamePrefix("ThreadPoolTaskScheduler"); 28 | scheduler.setPoolSize(1); 29 | scheduler.initialize(); 30 | return scheduler; 31 | } 32 | 33 | // Initially scheduler has no job 34 | @Override 35 | public void configureTasks(ScheduledTaskRegistrar taskRegistrar) { 36 | if (scheduledTaskRegistrar == null) { 37 | scheduledTaskRegistrar = taskRegistrar; 38 | } 39 | if (taskRegistrar.getScheduler() == null) { 40 | taskRegistrar.setScheduler(poolScheduler()); 41 | } 42 | } 43 | 44 | public boolean addJob(String jobName) { 45 | if (futureMap.containsKey(jobName)) { 46 | return false; 47 | } 48 | 49 | ScheduledFuture future = scheduledTaskRegistrar.getScheduler().schedule(() -> methodToBeExecuted(), t -> { 50 | Calendar nextExecutionTime = new GregorianCalendar(); 51 | Date lastActualExecutionTime = t.lastActualExecutionTime(); 52 | nextExecutionTime.setTime(lastActualExecutionTime != null ? lastActualExecutionTime : new Date()); 53 | nextExecutionTime.add(Calendar.SECOND, 5); 54 | return nextExecutionTime.getTime(); 55 | }); 56 | 57 | configureTasks(scheduledTaskRegistrar); 58 | futureMap.put(jobName, future); 59 | return true; 60 | } 61 | 62 | public boolean removeJob(String name) { 63 | if (!futureMap.containsKey(name)) { 64 | return false; 65 | } 66 | ScheduledFuture future = futureMap.get(name); 67 | future.cancel(true); 68 | futureMap.remove(name); 69 | return true; 70 | } 71 | 72 | public void methodToBeExecuted() { 73 | LOGGER.info("methodToBeExecuted: Next execution time of this will always be 5 seconds"); 74 | } 75 | 76 | } 77 | -------------------------------------------------------------------------------- /src/main/resources/application.properties: -------------------------------------------------------------------------------- 1 | spring.datasource.url=jdbc:h2:mem:testdb 2 | spring.datasource.driverClassName=org.h2.Driver 3 | spring.datasource.username=sa 4 | spring.datasource.password= 5 | spring.jpa.hibernate.ddl-auto=create 6 | -------------------------------------------------------------------------------- /src/test/java/com/mbcoder/scheduler/SchedulerApplicationTests.java: -------------------------------------------------------------------------------- 1 | package com.mbcoder.scheduler; 2 | 3 | import org.junit.Test; 4 | import org.junit.runner.RunWith; 5 | import org.springframework.boot.test.context.SpringBootTest; 6 | import org.springframework.test.context.junit4.SpringRunner; 7 | 8 | @RunWith(SpringRunner.class) 9 | @SpringBootTest 10 | public class SchedulerApplicationTests { 11 | 12 | @Test 13 | public void contextLoads() { 14 | } 15 | 16 | } 17 | --------------------------------------------------------------------------------