gistfile1.java

        final NioEventLoopGroup group = new NioEventLoopGroup();
        Bootstrap bs = new Bootstrap();
        bs.channel(NioDatagramChannel.class);
        bs.group(group);
        bs.handler(new ChannelInitializer<Channel>() {
            @Override
            protected void initChannel(Channel ch) throws Exception {
                ChannelPipeline pipeline = ch.pipeline();
                pipeline.addLast(new ChannelInboundHandlerAdapter() {
                    @Override
                    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
                        final DatagramPacket packet = (DatagramPacket) msg;
                        
                        ChannelFuture cf = connectRestServer(ctx.channel().eventLoop().parent());
                        cf.addListener(new ChannelFutureListener() {
                            @Override
                            public void operationComplete(ChannelFuture future) throws Exception {
                                if (!future.isSuccess()) {
                                    // something went wrong
                                    packet.release();
                                } else {
                                    ByteBuf content = packet.content();
                                    final Channel ch = future.channel();
                                    FullHttpRequest request = new DefaultFullHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.PUT, "/path", content);
                                    HttpHeaders.setContentLength(request, content.readableBytes());
                                    HttpHeaders.setKeepAlive(request, true);
                                    HttpHeaders.setHeader(request, HttpHeaders.Names.CONTENT_ENCODING, "application/json;charset=utf-8");
                                    ch.writeAndFlush(request).addListener(new ChannelFutureListener() {
                                        @Override
                                        public void operationComplete(ChannelFuture future) throws Exception {
                                            if (!future.isSuccess()) {
                                                // and remove from connection pool if you have one etc...
                                                ch.close();
                                            }
                                        }
                                    });
                                }
                            }
                        });
                    }

                    ChannelFuture connectRestServer(EventLoopGroup group) {
                        // TODO: Either bootstrap or use existing connection
                        return null;
                    }
                });

                
            }
        });
        bs.bind(9999).syncUninterruptibly();