You call the method several times, and you didn't say which of them causes the problem, so let me simply point out that BufferedReader's readLine() method is designed to return null after it reaches the end of its underlying data stream. There's nothing abnormal about that. It's up to your code to deal with the possibility.
Joined: Jun 23, 2011
the null pointer exception occurs at line 46 of the ClientChat Class. The program battleserver claims to be sending data to the pipe.