Проект FireNio

  <dependency>
  	<groupId>com.firenio</groupId>
  	<artifactId>firenio-all</artifactId>
  	<version>1.3.6</version>
  </dependency>  

  public static void main(String[] args) throws Exception {

      IoEventHandle eventHandleAdaptor = new IoEventHandle() {

          @Override
          public void accept(Channel ch, Frame f) throws Exception {
              String text = f.getStringContent();
              f.setContent(ch.allocateWithSkipHeader(1));
              f.write("yes server already accepted your message:", ch);
              f.write(text, ch);
              ch.writeAndFlush(f);
          }
      };
      ChannelAcceptor context = new ChannelAcceptor(8300);
      context.addChannelEventListener(new LoggerChannelOpenListener());
      context.setIoEventHandle(eventHandleAdaptor);
      context.addProtocolCodec(new LengthValueCodec());
      context.bind();
  }

  
  public static void main(String[] args) throws Exception {
      ChannelConnector context = new ChannelConnector("127.0.0.1", 8300);
      IoEventHandle eventHandle = new IoEventHandle() {
          @Override
          public void accept(Channel ch, Frame f) throws Exception {
              System.out.println();
              System.out.println("____________________" + f.getStringContent());
              System.out.println();
              context.close();
          }
      };

      context.setIoEventHandle(eventHandle);
      context.addChannelEventListener(new LoggerChannelOpenListener());
      context.addProtocolCodec(new LengthValueCodec());
      Channel          ch    = context.connect(3000);
      LengthValueFrame frame = new LengthValueFrame();
      frame.setString("hello server!", ch);
      ch.writeAndFlush(frame);
  }