Select the JVM Settings component under the relevant configuration in the Administration Console.
Check the Debug Enabled box.
To specify a different port (from 9009, the default) to use when attaching the JVM to a debugger, specify address= port-number in the Debug Options field.
If you wish to add JPDA options, add any desired JPDA debugging options in Debug Options. See JPDA Options .
For details, see the Sun Java System Application Server Enterprise Edition 8.1 2005Q2 Administration Guide.