How to connect n clients to a server?

[Norm]

I defined EDT in the following:
Sounds like you are using Swing's EDT (event dispatch thread) to run the code.

If you don't understand how not to conflict with Swing's EDT, you need to read the Tutorial. Look in the section on SwingUtilitiles invoke.... methods

[JosAH]

Kindly refer now to the update Model.java
Here's the link.

Oh great; you're showing us code that is not the code that produced the error. I am out of here.

Jos

edit: I read your crosspost in the Sun/Oracle forum; there you also don't understand what people are talking about so it's no use to repeat that fruitless discussion here. Consult the tutorials on the Java basics, threading and socket communication.