Can we register a listener for any event of a specific object?

Yes you can..

You just need to implement the performStartupProcess() and in that method you can control which object type and event should be invoked.

eg.

protected void performStartupProcess() throws ManagerException

  {

  try

  {

getManagerService().addEventListener(new ServiceEventListenerAdapter( this.getConceptualClassname() )

  {

                public void notifyVetoableEvent( Object event ) throws WTException,PropertyVetoException,WTPropertyVetoException

                {

                WorkInProgressServiceEvent persistenceEvent = (WorkInProgressServiceEvent)event;

  //System.out.println("\n\n .performStartupProcess() starting for POST_CHECKIN..");

                if( persistenceEvent.getEventTarget() instanceof WTPart)

  {

  Object object = persistenceEvent.getEventTarget();

  //handleUploadEvent(object);

  if(enablePostCheckIn.equalsIgnoreCase("true"))

  {

  handlePostCheckInEvent((WTPart)object);

  }

}

}

},WorkInProgressServiceEvent.generateEventKey(WorkInProgressServiceEvent.POST_CHECKIN));