SimonSays wrote:
So why is it that I read if you use <t:saveState> that the BB must implement
Serializable? So something that is serializable does not necessarily write
out a file system file, but can store the file in memory as well?
There are three options for saving a component tree:
(a) serialize it and send it to the client browser as a hidden input field
(b) serialize it and store it into the webserver's http session
(c) store it into the webserver's http session unserialized.
For (a) and (b), the object being saved must implement
java.io.Serializable, or javax.faces.component.StateHolder.
Option (c) is easier, but doesn't work with clustering, doesn't support
"hot restart" and doesn't allow the webserver to store a user's http
session on disk when memory gets short. It is therefore not the default;
you need to explicitly enable this mode (and I wouldn't recommend it).
Also if STATE_SAVING_METHOD set to "server" saves a "file" the the
HttpSession what does STATE_SAVING_METHOD set to "client" do differently?
MyFaces never "saves a file". It just places an object (which may be a
serialized object [b], or an unserialized one [c]) into the http
session. What the webserver does with a user's http session is up to it.
You may need to read about serialization; it is NOT just about writing
data to files on a disk.
how do I tell if the whole object is being serialized (state saved) rather
than just some property in a bean? I may hit the breakpoints but I want to
see the actual data somewhere and watch it get restored as well. I do not
believe <t:saveState> is working but do not know why. I need to know for
sure that it is not working before I go and try to find out why.
I can't think of any easy way to do this. Java serialization is pretty
complex, and not the sort of thing I would want to trace through. Maybe
you could define your own readObject/writeObject methods that just
delegate to the standard implementations to give yourself somewhere to
place your breakpoints but I've never needed to do that.
I assure you that t:saveState does work for many thousands of other
people out there (including myself).
Regards,
Simon
