├── .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 |
--------------------------------------------------------------------------------