CODEWITHSUNDEEP
springsessionrequest
shrini1000
shrini1000

Reputation: 7226

Spring calling 'destroy' method on session/request scoped beans

How does Spring know when to call 'destory' method on a session/request scoped bean (in other words, how does it detect that the concerned bean is going out of scope)?

I read somewhere that it uses request/session listeners to be notified of these events. But these listners need to be defined in web.xml, and there's no mention of defining such listeners in Spring literature. So how does this work?

Upvotes: 7

Views: 5627

Answers (3)

Gautam Kumar
Gautam Kumar

Reputation: 983

You can implement the interface DisposableBean and InitializingBean for session scoped bean.

The org.springframework.beans.factory.InitializingBean interface allows a bean to perform initialization work after all necessary properties on the bean have been set by the container. The InitializingBean interface specifies a single method afterPropertiesSet().

Implementing the org.springframework.beans.factory.DisposableBean interface allows a bean to get a callback when the container containing it is destroyed. The DisposableBean interface specifies a single method destroy().

Read more about it here: http://docs.spring.io/spring/docs/current/spring-framework-reference/html/beans.html#beans-factory-nature

Upvotes: 1

kan
kan

Reputation: 28951

The org.springframework.web.servlet.DispatcherServlet does it. It uses own code, e.g. the org.springframework.web.context.request.RequestAttributes#registerDestructionCallback callback list functionality to register all these scoped beans.

Upvotes: 2

Tomasz Nurkiewicz
Tomasz Nurkiewicz

Reputation: 340708

and there's no mention of defining such listeners in Spring literature

Oh, there is:

To support the scoping of beans at the request, session, and global session levels (web-scoped beans), some minor initial configuration is required before you define your beans.[...]

If you use a Servlet 2.4+ web container, [...] you need to add the following javax.servlet.ServletRequestListener to the declarations in your web applications web.xml file[...]

From: 4.5.4.1 Initial web configuration.

Also note that Spring does not call destroy on prototype-scoped beans.

Upvotes: 2

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