Execute when an application is destroyed/ undeployed

Question

I have a static initialization block where I read data from DB into certain variables, update that data during the lifetime of the application & save it to DB at regular periodic intervals but when the application is unexpectedly/suddently destroyed/ undeployed I want to write back the current state of the variable back to the DB.

How can I implement this with on destroy trigger in Java ?

Edit:

What about the @PreDestroy annotation, could it be useful for my case ?

anyone knows if the `finalize()` method would be useful for this purpose ? pros/cons ? — jambriz, Mar 30 '12 at 23:06

score 2 · Accepted Answer · answered Mar 30 '12 at 21:43

2

Assuming this is a web application, you can implement and register a ServletContextListener. Its contextInitialized method will be called once upon deployment, and contextDestroyed will be called once on undeployment.

However if the container is ungracefully terminated, contextDestroyed still may not have a chance to run.

See this page for an example of setting one up.

answered Mar 30 '12 at 21:43

Paul Bellora

54,340
18
130
181

Yes this is a webapp but since I was doing initization/intial read within a static initization block in a class, I was wondering it would be nice if I could trigger ondestroy within the same class, if possible ?! – Rajat Gupta Mar 30 '12 at 21:47
Running startup/shutdown logic based on class loading/unloading seems much less predictable. It's possible you could hook into the class being unloaded but I'm not the one to ask about this. – Paul Bellora Mar 30 '12 at 21:52

Execute when an application is destroyed/ undeployed

Edit:

1 Answers1