A Programmer many times try to locate and fix the bugs (errors) in the program code. Basic meaning of debugging a program is to start with a problem, isolate the source of the problem, and then fix it. When a programmer says he has debugged the program it means bugs has been worked out and bugs no longer exist.
From a Java Programmer there are a varieties of tools but if you are using an editor then it becomes quite easy for you to debug the program.