if (handler == null) { throw new IllegalStateException("Cannot find message handler"); }
ConsumerState state = getState(invocation); Client client = state.getCallbackClient(); client.removeListener(state.getMessageCallbackHandler()); client.disconnect();
   public Object handleClosing(Invocation invocation) throws Throwable   {      MessageCallbackHandler handler =         (MessageCallbackHandler)invocation.getMetaData(MetaDataConstants.JMS, MetaDataConstants.MESSAGE_HANDLER);            if (handler == null)      {         throw new IllegalStateException("Cannot find message handler");      }            handler.close();              return invocation.invokeNext();   }