serialized objects

This started again... a thread from *****:

What do you consider a best practice for serialVersionUID?

T

______________________________________________
From: *******
Sent: Thursday, November 15, 2007 10:45 AM
To: *******
Cc: *******
Subject: serilaVersionUID

Hi, *****, I realized that you changed the servialVersionUID in 11 TOs and make them unique. What is the purpose to make them unique?

Once the serilaVersionUID in TO is modified, both BPM and rule engine has to be deployed again. Now Dev rule engine is broken, and I am afraid Dev BPM (if it is running) also need redeploy.

*******


So after doing research again here is what I (*****) thinks:

The purpose of the serialVersionUID is to give the developer the control of when a class is compatible with previous versions and when not.
The consequence of this is that when the class changes, the developer needs to check that if the new class has compatible changes with previous versions, then keep the same number, if changes are not compatible, then change the number.
you can use the command: serialver to generate a serial version uid.
Articles:

[url=http://www.javaworld.com/javaworld/jw-02-2006/jw-0227-control.html?page=1]JavaWorld[/url]
[url=http://java.sun.com/j2se/1.5.0/docs/guide/serialization/spec/class.html#5421]Java Object Serialization Specification version 1.5.0[/url]