apport.jar contains the necessary class(es) for trapping uncaught Java
exceptions.  crash.class and crash.jar are used only by the test suite.

The crash handler, when invoked, opens a pipe to the java_uncaught_exception
script, and feeds it key/value pairs containing the relevant JVM state.

There is currently no automatic integration of this handler. You have to do

  import com.ubuntu.apport.*;

and in your main method install the handler with

  com.ubuntu.apport.ApportUncaughtExceptionHandler.install();