By default, System.out and System.err messages are directed to the JSR47 logger and written to the system trace files. You, however, can use parameters to redirect these messages to separate files.
To redirect system messages, perform the following step:
When you start the client, use one of the following parameters:
Parent topic: Logging
Instructs the client to write the System.out and System.err messages not only to the system trace file, but also to separate files in the <workspace>/logs directory, called SystemOut.log and SystemErr.log.
Instructs the client to not replace the System.out and System.err streams and to not log these messages to any persistent file.