code: @Override
  	public final void acknowledge() throws JMSException
      {
          AbstractSession session = getSession();
          
          int acknowledgeMode = session.getAcknowledgeMode();
          if (acknowledgeMode != Session.CLIENT_ACKNOWLEDGE)
              return; // Ignore [JMS SPEC]
          
          session.acknowledge();       
      }
docs: /* (non-Javadoc)
  @see javax.jms.Message#acknowledge()