Though you still have two weeks to turn in your first assignment, the second one is published too.
Do not worry because you have till December 20th, 2010.
This time it is a server what you have to do (a multi-threaded server). The good news is that the application protocol is very simple. After connecting to the server, the client may send one line of text containing an arithmetic expression (i.e. 1+2*3/4) and the server will respond with another text line containing the result of evaluating this expression (i.e. 2.5) or an error message if there is something wrong with the client expression.
Client will signal the server its willingness to quit by sending an empty line. Server will provide no other answer to the empty line but closing the connection.
Several clients can be using the server at the same time and all of them need to be served right away.
You can find here the Eval.java mentioned on the assignment text.