Exception handling for Spring 3.2 “@Scheduled” ann

Question

How to customize the exception handling for @Scheduled annotation from spring ?

I have Cron jobs which will be triggered in the server (Tomcat 6) and when any exceptions occur I need to do some handling.

• Spring version 3.2
• Tomcat Server 6

Answer 1

If you want to use Java Config you will need to create configuration implementing SchedulingConfigurer

@EnableScheduling
@Configuration
class SchedulingConfiguration implements SchedulingConfigurer {
    private final Logger logger = LoggerFactory.getLogger(getClass());
    private final ThreadPoolTaskScheduler taskScheduler;

    SchedulingConfiguration() {
        taskScheduler = new ThreadPoolTaskScheduler();
        taskScheduler.setErrorHandler(t -> logger.error("Exception in @Scheduled task. ", t));
        taskScheduler.setThreadNamePrefix("@scheduled-");

        taskScheduler.initialize();
    }

    @Override
    public void configureTasks(ScheduledTaskRegistrar taskRegistrar) {
        taskRegistrar.setScheduler(taskScheduler);
    }
}

You can modify error handler for your needs. Here I only log a message.

Don't forget to call taskScheduler.initialize();. Without it you'll get:

java.lang.IllegalStateException: ThreadPoolTaskScheduler not initialized

Answer 2

You could implement and register an ErrorHandler for the ThreadPoolTaskScheduler that is used for your scheduling annotations.

 <task:annotation-driven scheduler="yourThreadPoolTaskScheduler"  />

 <bean id="yourThreadPoolTaskScheduler" class="org.springframework.scheduling.concurrent.ThreadPoolTaskScheduler">
        <property name="poolSize" value="5" />
        <property name="errorHandler" ref="yourScheduledTaskErrorHandler" />
 </bean>

 <bean id="yourScheduledTaskErrorHandler" 
     class="com.example.YourScheduledTaskErrorHandler"/>

Answer 3

Why not wrap your business logic and do a simple try catch in your @schedule method. Then you can log or take whatever action is necessary for failure cases.

@Scheduled(cron = "${schedulerRate}")
public void scheduledJob() {
    try {
        businessLogicService.doBusinessLogic();
    } catch (Exception e) {
        log.error(e);
    }
}