Since there are so many classes and methods called from my class method, the debug log generated is very huge and getting truncated. How can i see the full debug log ? Is there a way through which i can set that log contains only those statements where i use System.debug().
If log size is execeeding some limit(I guess 2MB), it will truncate debug log. You can try changing log level in debug log to retrieve only important log, so that it will be within limit. In some cases since nothing was working, I have ended up creating records in a dummy object with the log I want.
I'd suggest using apex checkpoints to check the values. Alternatively, you could comment out some of the code after your debug.