I was reading this blog and it says that Sun JDK does not support hot deployment in case of method signature changes/new method gets added in classes etc. I also looked at bug detail on Sun's site. In the bug detail I could see a link for Sun's forum site that I could not browse because after Oracle took over Sun, the link is not working.
By any chance, any of you have any update on this?
This is still not possible and I'm not aware of any plans in the short term from Oracle or IBM to implement this in their JVMs.
That's why zero turnaround has stepped in and created JRebel. This does exactly what you ask. It allows hot deployment of classes being structurally modified.