Example usage for io.netty.channel.local LocalAddress LocalAddress

Introduction

In this page you can find the example usage for io.netty.channel.local LocalAddress LocalAddress.

Prototype

public LocalAddress(String id)

Source Link

Document

Creates a new instance with the specified ID.

Usage

From source file:com.flysoloing.learning.network.netty.localecho.LocalEcho.java

License:Apache License

public static void main(String[] args) throws Exception {
    // Address to bind on / connect to.
    final LocalAddress addr = new LocalAddress(PORT);

    EventLoopGroup serverGroup = new DefaultEventLoopGroup();
    EventLoopGroup clientGroup = new NioEventLoopGroup(); // NIO event loops are also OK
    try {/*w ww . j  a  v  a  2 s.  co  m*/
        // Note that we can use any event loop to ensure certain local channels
        // are handled by the same event loop thread which drives a certain socket channel
        // to reduce the communication latency between socket channels and local channels.
        ServerBootstrap sb = new ServerBootstrap();
        sb.group(serverGroup).channel(LocalServerChannel.class)
                .handler(new ChannelInitializer<LocalServerChannel>() {
                    @Override
                    public void initChannel(LocalServerChannel ch) throws Exception {
                        ch.pipeline().addLast(new LoggingHandler(LogLevel.INFO));
                    }
                }).childHandler(new ChannelInitializer<LocalChannel>() {
                    @Override
                    public void initChannel(LocalChannel ch) throws Exception {
                        ch.pipeline().addLast(new LoggingHandler(LogLevel.INFO), new LocalEchoServerHandler());
                    }
                });

        Bootstrap cb = new Bootstrap();
        cb.group(clientGroup).channel(LocalChannel.class).handler(new ChannelInitializer<LocalChannel>() {
            @Override
            public void initChannel(LocalChannel ch) throws Exception {
                ch.pipeline().addLast(new LoggingHandler(LogLevel.INFO), new LocalEchoClientHandler());
            }
        });

        // Start the server.
        sb.bind(addr).sync();

        // Start the client.
        Channel ch = cb.connect(addr).sync().channel();

        // Read commands from the stdin.
        System.out.println("Enter text (quit to end)");
        ChannelFuture lastWriteFuture = null;
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        for (;;) {
            String line = in.readLine();
            if (line == null || "quit".equalsIgnoreCase(line)) {
                break;
            }

            // Sends the received line to the server.
            lastWriteFuture = ch.writeAndFlush(line);
        }

        // Wait until all messages are flushed before closing the channel.
        if (lastWriteFuture != null) {
            lastWriteFuture.awaitUninterruptibly();
        }
    } finally {
        serverGroup.shutdownGracefully();
        clientGroup.shutdownGracefully();
    }
}

From source file:com.google.cloud.logging.spi.v2.testing.LocalLoggingHelper.java

License:Open Source License

/**
 * Constructs a new LocalPubsubHelper. The method start() must
 * be called before it is used./*from   ww w . j av a 2  s  .co m*/
 */
public LocalLoggingHelper(String addressString) {
    address = new LocalAddress(addressString);
    loggingImpl = new LocalLoggingImpl();
    NettyServerBuilder builder = NettyServerBuilder.forAddress(address).flowControlWindow(FLOW_CONTROL_WINDOW)
            .channelType(LocalServerChannel.class);
    builder.addService(LoggingServiceV2Grpc.bindService(loggingImpl));
    server = builder.build();
}

From source file:com.google.cloud.logging.v2.testing.LocalLoggingHelper.java

License:Apache License

/**
 * Constructs a new LocalLoggingHelper. The method start() must
 * be called before it is used.//from w  w w .ja v a 2  s  .c o  m
 */
public LocalLoggingHelper(String addressString) {
    address = new LocalAddress(addressString);
    loggingImpl = new LocalLoggingImpl();
    NettyServerBuilder builder = NettyServerBuilder.forAddress(address).flowControlWindow(FLOW_CONTROL_WINDOW)
            .channelType(LocalServerChannel.class);
    builder.addService(loggingImpl.bindService());
    server = builder.build();
}

From source file:com.hxr.javatone.concurrency.netty.official.localecho.LocalEcho.java

License:Apache License

public void run() throws Exception {
    // Address to bind on / connect to.
    final LocalAddress addr = new LocalAddress(port);

    EventLoopGroup serverGroup = new DefaultEventLoopGroup();
    EventLoopGroup clientGroup = new NioEventLoopGroup(); // NIO event loops are also OK
    try {//from  w w  w  . jav a  2 s . c  om
        // Note that we can use any event loop to ensure certain local channels
        // are handled by the same event loop thread which drives a certain socket channel
        // to reduce the communication latency between socket channels and local channels.
        ServerBootstrap sb = new ServerBootstrap();
        sb.group(serverGroup).channel(LocalServerChannel.class)
                .handler(new ChannelInitializer<LocalServerChannel>() {
                    @Override
                    public void initChannel(LocalServerChannel ch) throws Exception {
                        ch.pipeline().addLast(new LoggingHandler(LogLevel.INFO));
                    }
                }).childHandler(new ChannelInitializer<LocalChannel>() {
                    @Override
                    public void initChannel(LocalChannel ch) throws Exception {
                        ch.pipeline().addLast(new LoggingHandler(LogLevel.INFO), new LocalEchoServerHandler());
                    }
                });

        Bootstrap cb = new Bootstrap();
        cb.group(clientGroup).channel(LocalChannel.class).handler(new ChannelInitializer<LocalChannel>() {
            @Override
            public void initChannel(LocalChannel ch) throws Exception {
                ch.pipeline().addLast(new LoggingHandler(LogLevel.INFO), new LocalEchoClientHandler());
            }
        });

        // Start the server.
        sb.bind(addr).sync();

        // Start the client.
        Channel ch = cb.connect(addr).sync().channel();

        // Read commands from the stdin.
        System.out.println("Enter text (quit to end)");
        ChannelFuture lastWriteFuture = null;
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        for (;;) {
            String line = in.readLine();
            if (line == null || "quit".equalsIgnoreCase(line)) {
                break;
            }

            // Sends the received line to the server.
            lastWriteFuture = ch.writeAndFlush(line);
        }

        // Wait until all messages are flushed before closing the channel.
        if (lastWriteFuture != null) {
            lastWriteFuture.awaitUninterruptibly();
        }
    } finally {
        serverGroup.shutdownGracefully();
        clientGroup.shutdownGracefully();
    }
}

From source file:com.lambdaworks.redis.ConnectionEventTrigger.java

License:Apache License

static SocketAddress remote(ChannelHandlerContext ctx) {
    if (ctx.channel() != null && ctx.channel().remoteAddress() != null) {
        return ctx.channel().remoteAddress();
    }/*from w  ww  .  j  av  a  2 s.  co m*/
    return new LocalAddress("unknown");
}

From source file:com.lambdaworks.redis.metrics.CommandLatencyIdTest.java

License:Apache License

@Test
public void testValues() throws Exception {
    assertThat(sut.localAddress()).isEqualTo(LocalAddress.ANY);
    assertThat(sut.remoteAddress()).isEqualTo(new LocalAddress("me"));
}

From source file:com.springapp.mvc.netty.example.localecho.LocalEcho.java

License:Apache License

public static void main(String[] args) throws Exception {
    // Address to bind on / connect to.
    final LocalAddress addr = new LocalAddress(PORT);

    EventLoopGroup serverGroup = new LocalEventLoopGroup();
    EventLoopGroup clientGroup = new NioEventLoopGroup(); // NIO event loops are also OK
    try {//from   ww w . j  a v a2 s .c  om
        // Note that we can use any event loop to ensure certain local channels
        // are handled by the same event loop thread which drives a certain socket channel
        // to reduce the communication latency between socket channels and local channels.
        ServerBootstrap sb = new ServerBootstrap();
        sb.group(serverGroup).channel(LocalServerChannel.class)
                .handler(new ChannelInitializer<LocalServerChannel>() {
                    @Override
                    public void initChannel(LocalServerChannel ch) throws Exception {
                        ch.pipeline().addLast(new LoggingHandler(LogLevel.INFO));
                    }
                }).childHandler(new ChannelInitializer<LocalChannel>() {
                    @Override
                    public void initChannel(LocalChannel ch) throws Exception {
                        ch.pipeline().addLast(new LoggingHandler(LogLevel.INFO), new LocalEchoServerHandler());
                    }
                });

        Bootstrap cb = new Bootstrap();
        cb.group(clientGroup).channel(LocalChannel.class).handler(new ChannelInitializer<LocalChannel>() {
            @Override
            public void initChannel(LocalChannel ch) throws Exception {
                ch.pipeline().addLast(new LoggingHandler(LogLevel.INFO), new LocalEchoClientHandler());
            }
        });

        // Start the server.
        sb.bind(addr).sync();

        // Start the client.
        Channel ch = cb.connect(addr).sync().channel();

        // Read commands from the stdin.
        System.out.println("Enter text (quit to end)");
        ChannelFuture lastWriteFuture = null;
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        for (;;) {
            String line = in.readLine();
            if (line == null || "quit".equalsIgnoreCase(line)) {
                break;
            }

            // Sends the received line to the server.
            lastWriteFuture = ch.writeAndFlush(line);
        }

        // Wait until all messages are flushed before closing the channel.
        if (lastWriteFuture != null) {
            lastWriteFuture.awaitUninterruptibly();
        }
    } finally {
        serverGroup.shutdownGracefully();
        clientGroup.shutdownGracefully();
    }
}

From source file:com.twitter.http2.HttpHeaderCompressionTest.java

License:Apache License

private void testHeaderEcho(HttpHeaderBlockFrame frame) throws Throwable {
    final EchoHandler sh = new EchoHandler();
    final TestHandler ch = new TestHandler(frame);

    ServerBootstrap sb = new ServerBootstrap().group(new LocalEventLoopGroup())
            .channel(LocalServerChannel.class).childHandler(new ChannelInitializer<LocalChannel>() {
                @Override//from   w  w w. j a  va2 s  .co m
                public void initChannel(LocalChannel channel) throws Exception {
                    channel.pipeline().addLast(new HttpConnectionHandler(true), sh);
                }
            });
    Bootstrap cb = new Bootstrap().group(new LocalEventLoopGroup()).channel(LocalChannel.class)
            .handler(new ChannelInitializer<LocalChannel>() {
                @Override
                public void initChannel(LocalChannel channel) throws Exception {
                    channel.pipeline().addLast(new HttpConnectionHandler(false), ch);
                }
            });

    LocalAddress localAddress = new LocalAddress("HttpHeaderCompressionTest");
    Channel sc = sb.bind(localAddress).sync().channel();
    ChannelFuture ccf = cb.connect(localAddress);
    assertTrue(ccf.awaitUninterruptibly().isSuccess());

    while (!ch.success) {
        if (sh.exception.get() != null) {
            break;
        }
        if (ch.exception.get() != null) {
            break;
        }

        try {
            Thread.sleep(1);
        } catch (InterruptedException e) {
            // Ignore.
        }
    }

    sc.close().awaitUninterruptibly();
    cb.group().shutdownGracefully();
    sb.group().shutdownGracefully();

    if (sh.exception.get() != null && !(sh.exception.get() instanceof IOException)) {
        throw sh.exception.get();
    }
    if (ch.exception.get() != null && !(ch.exception.get() instanceof IOException)) {
        throw ch.exception.get();
    }
    if (sh.exception.get() != null) {
        throw sh.exception.get();
    }
    if (ch.exception.get() != null) {
        throw ch.exception.get();
    }
}

From source file:dorkbox.network.Client.java

License:Apache License

/**
 * Starts a REMOTE <b>only</b> client, which will connect to the specified host using the specified Connections Options
 *//*  w w w  .  j a  v a  2  s .com*/
@SuppressWarnings("AutoBoxing")
public Client(final Configuration config) throws SecurityException {
    super(config);

    String threadName = Client.class.getSimpleName();

    this.config = config;
    boolean hostConfigured = (config.tcpPort > 0 || config.udpPort > 0) && config.host != null;
    boolean isLocalChannel = config.localChannelName != null;

    if (isLocalChannel && hostConfigured) {
        String msg = threadName
                + " Local channel use and TCP/UDP use are MUTUALLY exclusive. Unable to determine what to do.";
        logger.error(msg);
        throw new IllegalArgumentException(msg);
    }

    localChannelName = config.localChannelName;
    hostName = config.host;

    Bootstrap localBootstrap = null;
    Bootstrap tcpBootstrap = null;
    Bootstrap udpBootstrap = null;

    if (config.localChannelName != null) {
        localBootstrap = new Bootstrap();
    }

    if (config.tcpPort > 0 || config.udpPort > 0) {
        if (config.host == null) {
            throw new IllegalArgumentException("You must define what host you want to connect to.");
        }

        if (config.host.equals("0.0.0.0")) {
            throw new IllegalArgumentException(
                    "You cannot connect to 0.0.0.0, you must define what host you want to connect to.");
        }
    }

    if (config.tcpPort > 0) {
        tcpBootstrap = new Bootstrap();
    }

    if (config.udpPort > 0) {
        udpBootstrap = new Bootstrap();
    }

    if (localBootstrap == null && tcpBootstrap == null && udpBootstrap == null) {
        throw new IllegalArgumentException(
                "You must define how you want to connect, either LOCAL channel name, TCP port, or UDP port");
    }

    if (config.localChannelName != null) {
        // no networked bootstraps. LOCAL connection only

        bootstraps.add(new BootstrapWrapper("LOCAL", config.localChannelName, -1, localBootstrap));

        localBootstrap.group(newEventLoop(LOCAL, 1, threadName + "-JVM-BOSS")).channel(LocalChannel.class)
                .remoteAddress(new LocalAddress(config.localChannelName))
                .handler(new RegistrationLocalHandlerClient(threadName, registrationWrapper));
    }

    EventLoopGroup workerEventLoop = null;
    if (tcpBootstrap != null || udpBootstrap != null) {
        workerEventLoop = newEventLoop(config.workerThreadPoolSize, threadName);
    }

    if (tcpBootstrap != null) {
        bootstraps.add(new BootstrapWrapper("TCP", config.host, config.tcpPort, tcpBootstrap));

        if (OS.isAndroid()) {
            // android ONLY supports OIO (not NIO)
            tcpBootstrap.channel(OioSocketChannel.class);
        } else if (OS.isLinux() && NativeLibrary.isAvailable()) {
            // epoll network stack is MUCH faster (but only on linux)
            tcpBootstrap.channel(EpollSocketChannel.class);
        } else if (OS.isMacOsX() && NativeLibrary.isAvailable()) {
            // KQueue network stack is MUCH faster (but only on macosx)
            tcpBootstrap.channel(KQueueSocketChannel.class);
        } else {
            tcpBootstrap.channel(NioSocketChannel.class);
        }

        tcpBootstrap.group(newEventLoop(1, threadName + "-TCP-BOSS"))
                .option(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT)
                .option(ChannelOption.WRITE_BUFFER_WATER_MARK,
                        new WriteBufferWaterMark(WRITE_BUFF_LOW, WRITE_BUFF_HIGH))
                .remoteAddress(config.host, config.tcpPort).handler(new RegistrationRemoteHandlerClientTCP(
                        threadName, registrationWrapper, workerEventLoop));

        // android screws up on this!!
        tcpBootstrap.option(ChannelOption.TCP_NODELAY, !OS.isAndroid()).option(ChannelOption.SO_KEEPALIVE,
                true);
    }

    if (udpBootstrap != null) {
        bootstraps.add(new BootstrapWrapper("UDP", config.host, config.udpPort, udpBootstrap));

        if (OS.isAndroid()) {
            // android ONLY supports OIO (not NIO)
            udpBootstrap.channel(OioDatagramChannel.class);
        } else if (OS.isLinux() && NativeLibrary.isAvailable()) {
            // epoll network stack is MUCH faster (but only on linux)
            udpBootstrap.channel(EpollDatagramChannel.class);
        } else if (OS.isMacOsX() && NativeLibrary.isAvailable()) {
            // KQueue network stack is MUCH faster (but only on macosx)
            udpBootstrap.channel(KQueueDatagramChannel.class);
        } else {
            udpBootstrap.channel(NioDatagramChannel.class);
        }

        udpBootstrap.group(newEventLoop(1, threadName + "-UDP-BOSS"))
                .option(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT)
                // Netty4 has a default of 2048 bytes as upper limit for datagram packets.
                .option(ChannelOption.RCVBUF_ALLOCATOR, new FixedRecvByteBufAllocator(EndPoint.udpMaxSize))
                .option(ChannelOption.WRITE_BUFFER_WATER_MARK,
                        new WriteBufferWaterMark(WRITE_BUFF_LOW, WRITE_BUFF_HIGH))
                .localAddress(new InetSocketAddress(0)) // bind to wildcard
                .remoteAddress(new InetSocketAddress(config.host, config.udpPort))
                .handler(new RegistrationRemoteHandlerClientUDP(threadName, registrationWrapper,
                        workerEventLoop));

        // Enable to READ and WRITE MULTICAST data (ie, 192.168.1.0)
        // in order to WRITE: write as normal, just make sure it ends in .255
        // in order to LISTEN:
        //    InetAddress group = InetAddress.getByName("203.0.113.0");
        //    NioDatagramChannel.joinGroup(group);
        // THEN once done
        //    NioDatagramChannel.leaveGroup(group), close the socket
        udpBootstrap.option(ChannelOption.SO_BROADCAST, false).option(ChannelOption.SO_SNDBUF, udpMaxSize);
    }
}

From source file:dorkbox.network.Server.java

License:Apache License

/**
 * Convenience method to starts a server with the specified Connection Options
 *///from   w ww  .  ja v  a 2s . c o  m
@SuppressWarnings("AutoBoxing")
public Server(Configuration config) throws SecurityException {
    // watch-out for serialization... it can be NULL incoming. The EndPoint (superclass) sets it, if null, so
    // you have to make sure to use this.serialization
    super(config);

    tcpPort = config.tcpPort;
    udpPort = config.udpPort;

    localChannelName = config.localChannelName;

    if (config.host == null) {
        // we set this to "0.0.0.0" so that it is clear that we are trying to bind to that address.
        hostName = "0.0.0.0";

        // make it clear that this is what we do (configuration wise) so that variable examination is consistent
        config.host = hostName;
    } else {
        hostName = config.host;
    }

    if (localChannelName != null) {
        localBootstrap = new ServerBootstrap();
    } else {
        localBootstrap = null;
    }

    if (tcpPort > 0) {
        tcpBootstrap = new ServerBootstrap();
    } else {
        tcpBootstrap = null;
    }

    if (udpPort > 0) {
        // This is what allows us to have UDP behave "similar" to TCP, in that a session is established based on the port/ip of the
        // remote connection. This allows us to reuse channels and have "state" for a UDP connection that normally wouldn't exist.
        // Additionally, this is what responds to discovery broadcast packets
        udpBootstrap = new SessionBootstrap(tcpPort, udpPort);
    } else {
        udpBootstrap = null;
    }

    String threadName = Server.class.getSimpleName();

    // always use local channels on the server.
    if (localBootstrap != null) {
        localBootstrap
                .group(newEventLoop(LOCAL, 1, threadName + "-JVM-BOSS"), newEventLoop(LOCAL, 1, threadName))
                .channel(LocalServerChannel.class)
                .option(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT)
                .option(ChannelOption.WRITE_BUFFER_WATER_MARK,
                        new WriteBufferWaterMark(WRITE_BUFF_LOW, WRITE_BUFF_HIGH))
                .localAddress(new LocalAddress(localChannelName))
                .childHandler(new RegistrationLocalHandlerServer(threadName, registrationWrapper));
    }

    EventLoopGroup workerEventLoop = null;
    if (tcpBootstrap != null || udpBootstrap != null) {
        workerEventLoop = newEventLoop(config.workerThreadPoolSize, threadName);
    }

    if (tcpBootstrap != null) {
        if (OS.isAndroid()) {
            // android ONLY supports OIO (not NIO)
            tcpBootstrap.channel(OioServerSocketChannel.class);
        } else if (OS.isLinux() && NativeLibrary.isAvailable()) {
            // epoll network stack is MUCH faster (but only on linux)
            tcpBootstrap.channel(EpollServerSocketChannel.class);
        } else if (OS.isMacOsX() && NativeLibrary.isAvailable()) {
            // KQueue network stack is MUCH faster (but only on macosx)
            tcpBootstrap.channel(KQueueServerSocketChannel.class);
        } else {
            tcpBootstrap.channel(NioServerSocketChannel.class);
        }

        // TODO: If we use netty for an HTTP server,
        // Beside the usual ChannelOptions the Native Transport allows to enable TCP_CORK which may come in handy if you implement a HTTP Server.

        tcpBootstrap
                .group(newEventLoop(1, threadName + "-TCP-BOSS"),
                        newEventLoop(1, threadName + "-TCP-REGISTRATION"))
                .option(ChannelOption.SO_BACKLOG, backlogConnectionCount)
                .option(ChannelOption.SO_REUSEADDR, true)
                .option(ChannelOption.WRITE_BUFFER_WATER_MARK,
                        new WriteBufferWaterMark(WRITE_BUFF_LOW, WRITE_BUFF_HIGH))

                .childOption(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT)
                .childOption(ChannelOption.SO_KEEPALIVE, true)
                .childHandler(new RegistrationRemoteHandlerServerTCP(threadName, registrationWrapper,
                        workerEventLoop));

        // have to check options.host for "0.0.0.0". we don't bind to "0.0.0.0", we bind to "null" to get the "any" address!
        if (hostName.equals("0.0.0.0")) {
            tcpBootstrap.localAddress(tcpPort);
        } else {
            tcpBootstrap.localAddress(hostName, tcpPort);
        }

        // android screws up on this!!
        tcpBootstrap.option(ChannelOption.TCP_NODELAY, !OS.isAndroid()).childOption(ChannelOption.TCP_NODELAY,
                !OS.isAndroid());
    }

    if (udpBootstrap != null) {
        if (OS.isAndroid()) {
            // android ONLY supports OIO (not NIO)
            udpBootstrap.channel(OioDatagramChannel.class);
        } else if (OS.isLinux() && NativeLibrary.isAvailable()) {
            // epoll network stack is MUCH faster (but only on linux)
            udpBootstrap.channel(EpollDatagramChannel.class);
        } else if (OS.isMacOsX() && NativeLibrary.isAvailable()) {
            // KQueue network stack is MUCH faster (but only on macosx)
            udpBootstrap.channel(KQueueDatagramChannel.class);
        } else {
            // windows and linux/mac that are incompatible with the native implementations
            udpBootstrap.channel(NioDatagramChannel.class);
        }

        // Netty4 has a default of 2048 bytes as upper limit for datagram packets, we want this to be whatever we specify
        FixedRecvByteBufAllocator recvByteBufAllocator = new FixedRecvByteBufAllocator(EndPoint.udpMaxSize);

        udpBootstrap
                .group(newEventLoop(1, threadName + "-UDP-BOSS"),
                        newEventLoop(1, threadName + "-UDP-REGISTRATION"))
                .option(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT)
                .option(ChannelOption.RCVBUF_ALLOCATOR, recvByteBufAllocator)
                .option(ChannelOption.WRITE_BUFFER_WATER_MARK,
                        new WriteBufferWaterMark(WRITE_BUFF_LOW, WRITE_BUFF_HIGH))

                // a non-root user can't receive a broadcast packet on *nix if the socket is bound on non-wildcard address.
                // TODO: move broadcast to it's own handler, and have UDP server be able to be bound to a specific IP
                // OF NOTE: At the end in my case I decided to bind to .255 broadcast address on Linux systems. (to receive broadcast packets)
                .localAddress(udpPort) // if you bind to a specific interface, Linux will be unable to receive broadcast packets! see: http://developerweb.net/viewtopic.php?id=5722
                .childHandler(new RegistrationRemoteHandlerServerUDP(threadName, registrationWrapper,
                        workerEventLoop));

        // // have to check options.host for null. we don't bind to 0.0.0.0, we bind to "null" to get the "any" address!
        // if (hostName.equals("0.0.0.0")) {
        //     udpBootstrap.localAddress(hostName, tcpPort);
        // }
        // else {
        //     udpBootstrap.localAddress(udpPort);
        // }

        // Enable to READ from MULTICAST data (ie, 192.168.1.0)
        // in order to WRITE: write as normal, just make sure it ends in .255
        // in order to LISTEN:
        //    InetAddress group = InetAddress.getByName("203.0.113.0");
        //    socket.joinGroup(group);
        // THEN once done
        //    socket.leaveGroup(group), close the socket
        // Enable to WRITE to MULTICAST data (ie, 192.168.1.0)
        udpBootstrap.option(ChannelOption.SO_BROADCAST, false).option(ChannelOption.SO_SNDBUF, udpMaxSize);
    }
}