Usage

Java Daemon based on Java Service Wrapper

The following shows how to generate start scripts to make an application run as a Linux daemon.

The setup is based on Java Service Wrapper (JSW) version 3.2.3, using the WrapperSimpleApp Integration.

Minimal configuration

In pom.xml:

<project>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>appassembler-maven-plugin</artifactId>
        <version>1.2.2</version>        
        <configuration>
          <repositoryLayout>flat</repositoryLayout>
          <includeConfigurationDirectoryInClasspath>true</includeConfigurationDirectoryInClasspath>         

          <daemons>
            <daemon>
              <id>app1</id>
              <mainClass>org.codehaus.mojo.SomeMainClass</mainClass>
              <commandLineArguments>
                <commandLineArgument>start</commandLineArgument>
              </commandLineArguments>
              <platforms>
                <platform>jsw</platform>
              </platforms>              
            </daemon>
          </daemons>
        </configuration>
        <executions>
          <execution>
            <id>generate-jsw-scripts</id>
            <phase>package</phase>
            <goals>
              <goal>generate-daemons</goal>
            </goals>
          </execution>
        </executions>
      </plugin>
    </plugins>
  </build>
</project>

Using the generated scripts

  • All dependencies and the artifact itself are placed in target/appassembler/lib directory.
  • The JSW bin scripts and configuration are placed in target/jsw/app1 directory.
$ mvn package

$ chmod +x target/jsw/app1/bin/app1

$ chmod +x target/jsw/app1/bin/wrapper-linux-x86-32

$ target/jsw/app1/bin/app1 start

$ ps -ef | grep java
(to check that it is running)

$ target/jsw/app1/bin/app1 stop

Add application specific shutdown code

  • The JSW default stop script use the "kill" command. Use a shutdown hook to override this behaviour with application specific shutdown code.

    E.g. add something like the following to your Main method:

    Runtime.getRuntime().addShutdownHook(new Thread(){
    public void run() {
        log.debug("Shutdown hook was invoked. Shutting down App1.");
        App1JmxStopper appJmxStopper = new App1JmxStopper();
        appJmxStopper.stop();
    }
});