Is that possible for client 2 client chat thru rmi without
using socket and threads..
Short answer NO
RMI uses sockets, you need Threads because your chat program will have to handle both user input and watch for chat messages. (obscure-refrence)there is no royal road to chat(/obscure-reference)
There are many many ways to implement distributed chat in
Java.
Personally I think the Java Message Service is an excellent choice.
Bill