Question

Can someone list the practical use cases of Request , Session and Global-Session scoped beans ? In most of the projects I have been using singleton and prototype . I understand that request scope beans are instantiated per request and in session scoped beans , the beans are instantiated when a session gets started .

Please enlighten me on the practical aspects .

Answer 1

So far we’re using request scoped beans for information that should only be valid on one page like the result of a search or the confirmation of an order. The bean will be valid until the page is reloaded.

A session scoped bean is useful to hold authentication information getting invalidated when the session is closed (by timeout or logout). You can store other user information that you don’t want to reload with every request here as well. Or another use case for us is to store a conversation scope in the session scope which we use to persist information between requests but to that we can assign a custom timeout and invalidation condition.

Pretty much any information that needs to be available after the request needs to be stored in the session scope. The only exception we use is with a view scope that stores information in the page’s view map to be available after ajax requests for example in wizzards.

Singleton scope however means, that the information exists only once per application so if two users request your page they will access the same information. This is usefull for controllers, as they shouldn’t store data anyway.

A prototype scope is the same as initialitzing an object with new, as it is created every time you inject it. We don’t use this at all at the moment.