从Servlet访问JSF ViewScoped托管bean

Question

How may I access a JSF ViewScoped managed bean from a Servlet?

(Assume that the managed bean in question has already been created, and still not been destroyed)

Answer 1

View-scoped variables are stored in the view map on the component tree. To access this data outside the view context you would have to create a JSF context and restore the view for the request. This involves rewriting much of the functionality provided by the JSF container .

JSF 2 provides mechanisms for interacting with server-side state without a page refresh: AJAX tags and the JSF JavaScript API . I would look at utilizing those if possible.

Alternatively, place the data into a scope that is easily accessible via servlets (the session.)

Since the view state is generally held in the session, it is likely technically possible to access the view state from here. But this would involve implementation-specific hacks that may not survive an upgrade of the underlying framework. I wouldn't even look at this as a solution.