For a chat room, you'll actually have to write two parts: A chat server, and then chat clients that connect to the chat server.
This means learning to use network sockets, in addition to threads for the chat server. Not exactly a beginner's problem, but still very doable if you have the right documentation.
Now the question gets more basic: do you have a computer to run the chat server on, that anyone you want access to would be able to use?
Some things that might be helpful:
http://java.sun.com/docs/books/tutorial/ - For going over the Java language itself
http://java.sun.com/docs/books/tutorial/essential/threads/index.html - Threads, to handle lots of things at once
http://java.sun.com/docs/books/tutorial/networking/sockets/ - To do the networking
http://java.sun.com/docs/books/tutorial/applet/index.html - For the client applets
That should be everything you need.
This means learning to use network sockets, in addition to threads for the chat server. Not exactly a beginner's problem, but still very doable if you have the right documentation.
Now the question gets more basic: do you have a computer to run the chat server on, that anyone you want access to would be able to use?
Some things that might be helpful:
http://java.sun.com/docs/books/tutorial/ - For going over the Java language itself
http://java.sun.com/docs/books/tutorial/essential/threads/index.html - Threads, to handle lots of things at once
http://java.sun.com/docs/books/tutorial/networking/sockets/ - To do the networking
http://java.sun.com/docs/books/tutorial/applet/index.html - For the client applets
That should be everything you need.
