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);
}