Debugging spring applications

Once we spring enable the application, how do we debug the problems. Does spring app write to any log files about the session management/transaction management.

I'm sorry if it's trivial.

Thanks!

Spring strapbooting your application, you can use your usual debugging strategy on runtime for your own code.
As for spring internals, it is stuff with precise logs based on commons-logging. If you set it to debug level, you'll see that the quantity of information to spot problems is really high.