Multiple Invocations of Spring Scheduled Task

Hey everyone,

So I am having a bit of a problem with some scheduled tasks I have declared using Spring's @Scheduled annotation. First off here is my app-config:

<beans <!--Namespaces-->>
    <!-- Search for annotated beans -->
    <context:component-scan  base-package="com.my.package.task"/>

    <task:annotation-driven executor="myExecutor" scheduler="myScheduler"/>

    <task:executor id="myExecutor" pool-size="5"/>

    <task:scheduler id="myScheduler" pool-size="10"/>

    <tx:annotation-driven/>
</beans>

I also have a AppConfig class:

@Configuration
@ImportResource("classpath:/config/app-config.xml")
public class AppConfig {
     //Bean declarations but NO references to the Scheduled tasks or their classes
}

And here are the scheduled tasks I have declared:

public abstract class ScheduledTask {
     private ApplicationContext appContext;

     abstract void doSomething();

     protected getAppContext() {
          if(appContext == null) {
               appContext = new AnnotationConfigApplicationContext(AppConfig.class);
          }

          return appContext;
     }
     //Other common methods
}

@Service
public class Task1 extends ScheduledTask {    
     @Scheduled(cron="0 0 9 * * MON-FRI")
     public void doSomething() {
        System.out.println("Task1 -- Thread ID: " + Thread.currentThread().getId() + " Thread Name: " + Thread.currentThread().getName());
         //Update the database with new values
     }
}

@Service
public class Task2 extends Scheduledtask {
     @Scheduled(cron="0 0 10 * * MON-FRI")
     public void doSomething() {
          System.out.println("Task2 -- Thread ID: " + Thread.currentThread().getId() + " Thread Name: " + Thread.currentThread().getName());
          //Get some data from database and send email with data from DB
     }
}

Now the problem I am getting is that when these tasks are run, I get multiple emails sent (see Task2). I added in the print statements to see if the methods were being called multiple times and Task2 is executed twice by 2 different threads. I would hope that Spring would only invoke a scheduled task once. Here is the output I get:

Task1 -- Thread ID: 10 Thread Name: myScheduler-1
Task2 -- Thread ID: 23 Thread Name: myScheduler-2
Task2 -- Thread ID: 11 Thread Name: myScheduler-2

And if I run it at night and set the cron jobs to be like 4hrs apart I start to get even more emails sent (thought I havent had a chance to see if this is due to multiple threads / method calls).

Does anyone have any ideas what could be causing the multiple invocations of the second task? I looked at the Spring Documentation and under the 'Note' it mentions that you can get multiple invocation if you initialize multiple instances of the @Scheduled class at runtime. Could that be happening here with my AppConfig and app-config.xml?

ansaurus

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Multiple Invocations of Spring Scheduled Task

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