Debugging Server-side Java with JPDA

JPDA stands for Java Platform Debugger Architecture. It is a new debugging design adopted by the VM that facilitates debuggers to attach to the VM process easily. More info about JPDA can be found here.

I tried out debugging a Struts application running on Tomcat using Eclipse. (Versions: Tomcat-5.0; Eclipse-3.1.2)
Here are the steps to be followed:

1. Start Tomcat in JPDA debug mode. For this, set up two variables in the environment as follows:
2. The first variable is: set JPDA_TRANSPORT=dt_socket (This tells the VM that the debugger would talk to the VM on Tcp sockets)
3. The second variable is: set JPDA_ADDRESS=8000 (This tells the VM the port on which it should listen for debugger connections)
4. Go to the command prompt and run the 'Catalina.bat' batch file present in {TomcatHome}\bin. On the command prompt pass the following argument: catalina jdpa start
5. Go to Eclipse and open the Debug window. Create a new configuration under 'Remote Java Application' . Make sure 'Connection Type' is Socket and port is 8000
6. Navigate the webapplication thru web browser and see Ur Eclipse stop at breakpoints..

Happy debugging............