All session objects should be serializable to replicate error.

Question

Hi All,
Having 'EmployeeBean' and it is having below properties with getters and setters methods
private long emp_id;
private String emp_name;
private java.sql.Timestamp date_of_join;
private boolean isActive;
private int dept_no;
Adding multiple employees(creating multiple EmployeeBean) into an ArrayList and storing this ArrayList into a Session object. This is working fine but when I move this code to production(cluster environment) it is throwing below error
<Aug 23, 2011 2:15:40 PM EDT> <Error> <Cluster> <BEA-000126> <All session objects should be serializable to replicate. Check the objects in your session. Failed to replicate non-serializable object.
java.rmi.MarshalException: failed to marshal update(Lweblogic.cluster.replication.ROID;ILjava.io.Serializable;Ljava.lang.Object;); nested exception is:
     java.io.NotSerializableException: my.company.beans.EmployeeBean
     at weblogic.rjvm.BasicOutboundRequest.marshalArgs(BasicOutboundRequest.java:90)
     at weblogic.rmi.internal.BasicRemoteRef.invoke(BasicRemoteRef.java:221)
     at weblogic.cluster.replication.ReplicationManager_1032_WLStub.update(Unknown Source)
     at sun.reflect.GeneratedMethodAccessor163.invoke(Unknown Source)
     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
     Truncated. see log file for complete stacktrace
Caused By: java.io.NotSerializableException: my.company.beans.EmployeeBean
     at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1156)
     at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:326)
     at java.util.ArrayList.writeObject(ArrayList.java:570)
     at sun.reflect.GeneratedMethodAccessor21.invoke(Unknown Source)
     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
     Truncated. see log file for complete stacktrace
Can someone please let me know, why I'm getting this error? The EmployeeBean should implement serializable? Is there any problems/cons to implement serializable?
Having other bean(LoginBean) and I'm keeping this bean into session and it doesn't implement serializable, not getting any error for this bean(LoginBean). Only difference is LoginBean is not added to ArrayList.
Why it is throwing error for EmployeeBean and not for LoginBean??
Thanks in advance.
Regards,
Sharath.

Answer 1

The EmployeeBean should implement serializable? - Yep Is there any problems/cons to implement serializable? - No
Just add java.io.Serializable to the EmployeeBean, for example,
public class EmployeeBean implements Serializable {
}For LoginBean you have probably, configured to be in the session, by using faces-config.xml.
In the case of EmployeeBean (or the object graph it is part of) have you used HttpSession.setAttribute(...)?
Note that setAtttibute(...) is the trigger for an application server to replicate the object.
In this case all objects in the object graph have to be serializable.
Typically, objects should be Serializable when they are part of the session and you are using a clustered environment.