Exception when setting javax.faces.STATE_SAVING_METHOD to "client"

Question

Hi everyone,
I have the following issue when in web.xml, I add the following code :
<context-param>
<param-name>javax.faces.STATE_SAVING_METHOD</param-name>
<param-value>client</param-value>
</context-param>
I have 1 managed bean (let's call it A) with a "session" scope. That bean A creates an instance of Bean B in its constructor, and B has a pointer back to A stored as a member variable. B is also a member variable of bean A. B is NOT a managed bean. The code looks like:
A () {
this.memberOfA = new B (this);
Then, B has an ArrayList member variable in which I add instances of a bean C. Each instance of bean C has a pointer back to B bean (the same way as between A and B). Similarly, C bean is NOT a managed bean.
Here is the issue: if in web.xml, I save the state on the client, I get the following exception :
org.apache.jasper.JasperException:
Error while saving state in 'session': 'com.foo.beans.C'.
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:254)
but, if I change web.xml to save the state on the server, everything is fine. Also, if I don't put any instances of C inside the ArrayList of B, then I don't have this issue at all, so the problem seems to happen when C instances are added into the ArrayList and when saving the state occurs on the client. Does anybody know why this happens ?
Thanks a lot,
Iannis

Answer 1

You would certainly have problems like this if:
* C is directly or indirectly referenced from a property or attribute of a component, and
* C is not Serializable.
The reason that selecting server-side state saving avoids this exception is that, in that scenario, the state is never serialized by the RI -- it is just saved in the HttpSession.
Craig