Spring: Inject bean depended on context (session/web or local thread/background process)

Question

Is it possible to create a factory or proxy that can decide if thread is running in (Web)Request or background-process (ie. scheduler) and then depending on that information, it creates a session bean or a prototype bean?

Example (pseudo Spring config :)

<bean id="userInfoSession" scope="session" />
<bean id="userInfoStatic" scope="prototype" />

<bean id="currentUserInfoFactory" />

<bean id="someService" class="...">
    <property name="userInfo" ref="currentUserInfoFactory.getCurrentUserInfo()" />
</bean>

I hope this makes my question easier to understand...

Answer 1

Your rephrase is indeed considerably simpler :)

Your currentUserInfoFactory could make use of RequestContextHolder.getRequestAttributes(). If a session is present and associated with the calling thread, then this will return a non-null object, and you can then safely retrieve the session-scoped bean from the context. If it returns a null, then you should fetch the prototype-scoped bean instead.

It's not very neat, but it's simple, and should work.

Answer 2

Create two custom context loaders that bind the same scope defintion to different implementations:

public final class SessionScopeContextLoader extends GenericXmlContextLoader {

   protected void customizeContext(final GenericApplicationContext context) {
     final SessionScope testSessionScope = new SessionScope();
     context.getBeanFactory().registerScope("superscope", testSessionScope);
   }
    ...
}

Then you make a corresponding one for singleton (make your own scope with just statics)

Then you just specify the appropriate context loader in the xml startup for each of the two contexts.