JSF SessionScopedmanagedBean与ViewScopedmanagedBean结合使用

Question

I have the following problem in my project:

We have 2 managed beans with the following configuration:

@ManagedBean
@SessionScoped
public class SessionBean {
    private PersonnelFile personnelFile; // + getters/setters
}

@ManagedBean
@ViewScoped
public class ViewBean {
    @ManagedProperty("#{sessionBean}")
    private SessionBean sessionBean;

    public void selectPersonnel() {
        sessionBean.getPersonnelFile().setPerson(new Person());
    }
}

This is not all of the code, but it gives you a general idea of the sitatution:

• SessionScoped bean which holds a session object
• ViewScoped bean which holds view-related objects and a reference to the SessionScoped bean

The problem now is:

• I access my view
• I make a few post-backs to the same view, coming back to the view every time.. so far so good
• At a certain moment, I set my session object in the SessionScoped bean with the information from the view and I leave my view... so far so good
• Now, when I return to this view, he creates a new ViewScoped bean instance (as expected) and sets the SessionScoped bean back (because of the ManagedProperty annotation)
• When I debug this, I can see that the reference to the SessionScoped bean remains the same, so it's the same object
• However, the object that I previously set in the SessionScoped bean has become null , meaning he 'lost' the session information about that object
• I never reset this object in the SessionScoped bean, so I don't see where it could have gone wrong...

If you want more explanation or if you want me to phrase this question better, let me know or use the edit button!

Answer 1

@BalusC I think we may have found the problem. In our web.xml, we were using the following setting:

 <context-param>
     <param-name>javax.faces.STATE_SAVING_METHOD</param-name>
     <param-value>client</param-value>
 </context-param>

Now, if I understand it correctly, we can't edit the state of a session-scoped bean through a view-scoped bean with this setting... The only way we have been able to change the state of the session-scoped bean, is in the constructor or PostConstruct method of the bean itself. Changes made to the session-scoped bean from inside the view-scoped bean were not persisted on the server.

If we set this variable to 'server', the state is indeed persisted on the server and not transmitted to the client every time. I understand this puts more load on the server in terms of memory, but I would like to know how we could solve our problem by using the client approach.

So, my problem is fixed, but I'm not sure if the solution is ideal...