code: public void changeSelectInterests()
      {
          switch (state)
          {
              case READY_TO_WRITE: // set the OP_WRITE interest
                  state = State.WRITING;
                  break;
  
              case READY_TO_READ_FRAME_SIZE:
                  state = State.READING_FRAME_SIZE;
                  break;
  
              case READY_TO_READ_FRAME:
                  state = State.READING_FRAME;
                  break;
  
              case AWAITING_CLOSE:
                  close();
                  selectionKey.cancel();
                  break;
  
              default:
                  logger.error("changeSelectInterest was called, but state is invalid (" + state + ")");
          }
      }
docs: Give this Message a chance to change its interests.