How to add shutdown hook in CQ5

[Former Community Member]

Hi there,

There is a case for me: i need to persist application some data before JVM shutdown. So i program as below in OSGI bundle:

protected void activate(ComponentContext ctx) { this.bundleContext = ctx.getBundleContext(); final Set<JobBean> jobs = CreateJobServlet.jobNames; jobs.addAll(getInProgressJob()); shutDownHook(jobs); } private Set<JobBean> getInProgressJob() { return getCustomerService().getInProgressJob(); } private void shutDownHook(final Set<JobBean> jobs) { logger.info("Exec shutDownHook()........."); Runtime.getRuntime().addShutdownHook(new Thread(){ public void run(){ logger.info("Running shutdown hook before JVM complete closed......"); getCustomerService().persisJob(jobs); } }); }

However, the function shutDownHook never enter and work, no any log info in background.

Anyone know how to do that? thanks a lot

Brian

[Jörg_Hoh · Accepted solution]

Hi Brian,

Adding a shutdown o the JVM is not best practice within AEM. Because when the JVM finally shuts down, most (all?) of the bundles have been already stopped. So instead of this shutdown hook I would rather tie it to the stop of a bundle or (preferably) to the deactivate of a service.

btw: When you are dealing with sling jobs, you don't have to deal with persisting the jobs yourself...

kind regards,
Jörg

[Former Community Member]

Yes, i find that log record bundle service can't cast class. See below code:

private CustomerService getCustomerService() { BundleContext ctx = FrameworkUtil.getBundle(this.getClass()) .getBundleContext(); ServiceReference serviceReference = ctx .getServiceReference(CustomerService.class.getName()); return CustomerService.class.cast(ctx.getService(serviceReference)); }

As a result,Do you mean to tie this task to the deactivate method as following:

protected void deactivate(ComponentContext ctx) { this.bundleContext = null; getCustomerService().persisJob(jobs); }

thanks a lot.

[Former Community Member]

I did try to use that you suggested, however cannot work and throws the same exception: the OSGI service is nullpointer.

[Jörg_Hoh]

Which OSGI service is null?

Jörg

[Former Community Member]

private CustomerService getCustomerService() { BundleContext ctx = FrameworkUtil.getBundle(this.getClass()) .getBundleContext(); ServiceReference serviceReference = ctx .getServiceReference(CustomerService.class.getName()); return CustomerService.class.cast(ctx.getService(serviceReference)); }

[smacdonald2008]

Look at this stackoverflow thread:

http://stackoverflow.com/questions/24570288/debug-osgi-component-activation-deactivation-issue

It touches upon some of the concepts here.

[smacdonald2008]

Also  does your OSGi service work when called in other places?

[Former Community Member]

sure, that work except JVM shutdown case.