gistfile1.java

@Test
    public void sendUdp() {

        Netty netty = new Netty();
        Channel channel = netty.bootstrap();
        try {
            ChannelFuture channelFuture = channel.writeAndFlush(new Object());
            channelFuture.addListener(new ChannelFutureListener() {
                public void operationComplete(ChannelFuture future) {
                    LOG.info("done!!");
                }
            });
            channelFuture.await(2, TimeUnit.SECONDS);
        } catch (Exception e) {
            LOG.info("exception", e);
        }
        channel.close();
        netty.shutdown();
    }
-------
public class Netty {

    static final Logger LOG = LoggerFactory.getLogger(CL_TELEMATIC);
    EventLoopGroup group = new NioEventLoopGroup();


    public Channel bootstrap() {

        try {
            Bootstrap b = new Bootstrap();
            b.group(group)
                    .channel(NioDatagramChannel.class)
                    .handler(new ChannelInitializer<NioDatagramChannel>() {
                        @Override
                        protected void initChannel(NioDatagramChannel nioDatagramChannel) throws Exception {
                            nioDatagramChannel.pipeline().addLast(new Handler());
                        }
                    });
            return b.bind("192.168.1.11", 20800).sync().channel();
        } catch (InterruptedException e) {
            LOG.error("netty exception", e);
            return null;

        }
    }

    public void shutdown(){
        group.shutdownGracefully();
    }
}

----


public class Handler extends ChannelOutboundHandlerAdapter {

    static final Logger LOG = LoggerFactory.getLogger(CL_TELEMATIC);


    @Override
    public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {

        try {
            LOG.info("in write method");
            ByteBuf buf = ctx.alloc().buffer();
            buf.writeByte(0x00);
            LOG.info("bytebuf allocating");
            DatagramPacket datagramPacket = new DatagramPacket(buf, new InetSocketAddress("200.72.211.71", 20800));
            LOG.info(datagramPacket.toString());
            ctx.writeAndFlush(datagramPacket);
            LOG.info("writing");
        } catch (Exception e) {
            LOG.info("exception", e);
        }

    }


}