Thanks Kris. You help me clear a lot of things. Now I'm facing a key problem. If you have seen my last post, I'm seeking for a way to notify the process of the sub-thread's completement, and send a possible return Object back with the signal. This is necessary for those tasks that are time consuming but their results are needed for subsequent process.
I've tried this idea on local in eclipse. But when I put it on web console, it threw exceptions out. I can't put such tasks running in the main thread, becasue it will block other processes from console as well. Could you advise on this, or if there are any alternatives?
Thanks,
Bruce