KfWiki: Scheduling tasks on jboss

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Scheduling tasks on jboss

Jboss comes with a scheduler. I'm not familiar with the terms so it's hard to provide a highlevel description. The following example works on jboss-4.3.2-GA

Create a Scheduler class

Nothing too fancy here, it implements the jboss Schedulable class, and writes a log whenever the perform() is called. This class file needs to be packaged as a jar file, and saved to the default/deploy/lib directory under jboss so jboss is able to access it on startup.

MyTask.java

import java.util.Date;

import org.jboss.varia.scheduler.Schedulable;

import org.apache.log4j.Logger;

public class MyTask implements Schedulable

{

    private static final Logger log = Logger.getLogger(MyTask.class);

    private String name;

    private long value;

    public MyTask(String name, long value)

    {

        this.name = name;

        this.value = value;

        log.info("constructor name: " + name + ", value: " + value);

    }

    public void perform(Date now, long remainingRepetitions)

    {

        log.info("perform, now: " + now +

                 ", remainingRepetitions: " + remainingRepetitions +

                 ", name: " + name + ", value: " + value);

    }

}

Deploy the scheduler service

In jboss's deploy directory, create a service.xml file, let's just call it myscehduler-service.xml. The Timer mbean is needed for every scheduler. If you plan on implementing more than 1 scheduler, you need another Timer mbean. The second mbean calls the MyTask scheduler. It also tell the scheduler when to start and how often it should be waken.

myscheduler-service.xml

<server>

<mbean code="org.jboss.mx.timer.JBossTimer" name="jboss:service=Timer"></mbean>

<mbean code="org.jboss.varia.scheduler.ScheduleManager" name="jboss:service=ScheduleManager">

    <attribute name="StartAtStartup">true</attribute>

    <attribute name="FixedRate">true</attribute>

</mbean>

    <mbean code="org.jboss.varia.scheduler.Scheduler"

           name="jboss.docs:service=Scheduler">

        <attribute name="StartAtStartup">true</attribute>

        <attribute name="SchedulableClass">MyTask</attribute>

        <attribute name="SchedulableArguments">TaskFoo,123456789</attribute>

        <attribute name="SchedulableArgumentTypes">java.lang.String,long</attribute>

        <attribute name="InitialStartDate">NOW</attribute>

        <attribute name="SchedulePeriod">60000</attribute>

        <attribute name="InitialRepetitions">-1</attribute>

    </mbean>

</server>

Start jboss

That's it. Once you have the jar file and xml file in place, you should start seeing these messages in server.log:

21:22:55,083 INFO  [MyTask] perform, now: Thu Feb 25 21:22:55 HKT 2010, remainingRepetitions: -1, name: TaskFoo, value: 123456789
21:23:55,083 INFO  [MyTask] perform, now: Thu Feb 25 21:23:55 HKT 2010, remainingRepetitions: -1, name: TaskFoo, value: 123456789
21:24:55,084 INFO  [MyTask] perform, now: Thu Feb 25 21:24:55 HKT 2010, remainingRepetitions: -1, name: TaskFoo, value: 123456789

KfWiki : JbossScheduler

Scheduling tasks on jboss

Create a Scheduler class

Deploy the scheduler service

Start jboss