My application uses commons logging simpleLog to print debug logs in the application server (systemOut) logs. Now I want to redirect my application's debug statements to a separate log file apart from the application server logs (systemOut, systemErr etc.).
What I understand from your post is that you want to have all the debug statements in a separate file. WebSphere already have a provision for this in the form of trace.log.
You can also configure the parameters like name, size, location etc. of debug logs. For this you need to login to WebSphere Admin Console & go to path: Application servers > server1 > Logging and Tracing > Diagnostic Trace Service
But for starting the generation of debug log, you need to enable debugging service at server start up. For this:
(1) Login to WebSphere Admin Console.
(2) Go To Application servers > server1 > Debugging Service
(3) Select the check box Enable service at server startup