netty基本用法

public class HelloClient {public static String host = "127.0.0.1"; ????public static int port = 7878; ?????/** ?????* @param args ?????* @throws InterruptedException ??????* @throws IOException ??????*/ ????public static void main(String[] args) throws InterruptedException, IOException { ????????EventLoopGroup workGroup = new NioEventLoopGroup(); ????????try { ????????????Bootstrap b = new Bootstrap(); ????????????b.group(workGroup) ????????????.channel(NioSocketChannel.class) ????????????.handler(new HelloClientInitializer()); ?????????????// 连接服务端 ????????????ChannelFuture future = b.connect(host, port).sync(); ?????????????????????????// 控制台输入 ????????????BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); ????????????for (;;) { ????????????????String line = in.readLine(); ????????????????if (line == null) { ????????????????????continue; ????????????????} ????????????????/* ?????????????????* 向服务端发送在控制台输入的文本 并用"\r\n"结尾 ?????????????????* 之所以用\r\n结尾 是因为我们在handler中添加了 DelimiterBasedFrameDecoder 帧解码。 ?????????????????* 这个解码器是一个根据\n符号位分隔符的解码器。所以每条消息的最后必须加上\n否则无法识别和解码 ?????????????????* */ ????????????????future.channel().writeAndFlush(line + "\r\n"); ????????????} ????????} finally { ????????????// The connection is closed automatically on shutdown. ????????workGroup.shutdownGracefully(); ????????} ????}}

public class HelloClientInitializer extends ChannelInitializer<SocketChannel> { ????protected void initChannel(SocketChannel ch) throws Exception { ????????ChannelPipeline pipeline = ch.pipeline(); ?????????/* ?????????* 这个地方的 必须和服务端对应上。否则无法正常解码和编码 ?????????* ??????????* 解码和编码 我将会在下一张为大家详细的讲解。再次暂时不做详细的描述 ?????????* ??????????* */ ????????pipeline.addLast("framer", new DelimiterBasedFrameDecoder(8192, Delimiters.lineDelimiter())); ????????pipeline.addLast("decoder", new StringDecoder()); ????????pipeline.addLast("encoder", new StringEncoder()); ?????????????????// 客户端的逻辑 ????????pipeline.addLast("handler", new HelloClientHandler()); ???}}

public class HelloClientHandler extends SimpleChannelInboundHandler<String> { ????@Override ????protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception { ?????????????????System.out.println("Server say : " + msg); ????} ?????????@Override ????public void channelActive(ChannelHandlerContext ctx) throws Exception { ????????System.out.println("Client active "); ????????super.channelActive(ctx); ????} ?????@Override ????public void channelInactive(ChannelHandlerContext ctx) throws Exception { ????????System.out.println("Client close "); ????????super.channelInactive(ctx); ????}}

public class HelloServer { /** ????* 服务端监听的端口地址 ????*/ ???private static final int portNumber = 7878; ???????public static void main(String[] args) throws InterruptedException { ???//第一个线程组用于接收client连接 ???????EventLoopGroup bossGroup = new NioEventLoopGroup(); ???????//第二个线程组用于具体的业务处理 ???????EventLoopGroup workerGroup = new NioEventLoopGroup(); ???????try { ???????//创建一个辅助类Boosatrap用于对Server进行一系列的配置 ???????????ServerBootstrap b = new ServerBootstrap(); ???????????//将两个线程组加入进来 ???????????b.group(bossGroup, workerGroup); ???????????//指定使用NioServerSocketChannel这种类型的通道 ???????????b.channel(NioServerSocketChannel.class); ???????????//一定要使用childHandler绑定具体的事件处理器 ???????????b.childHandler(new HelloServerInitializer()); ???????????????????????//SocketChannel通道的配置项（保持连接） ???????????b.option(ChannelOption.SO_KEEPALIVE, true); ???????????????????????// 服务器绑定端口监听 ???????????ChannelFuture f = b.bind(portNumber).sync(); ???????????// 监听服务器关闭监听 ???????????f.channel().closeFuture().sync(); ???????????// 可以简写为 ???????????/* b.bind(portNumber).sync().channel().closeFuture().sync(); */ ???????} finally { ???????????bossGroup.shutdownGracefully(); ???????????workerGroup.shutdownGracefully(); ???????} ???}}

public class HelloServerInitializer extends ChannelInitializer<SocketChannel> { ????@Override ????protected void initChannel(SocketChannel ch) throws Exception { ????????ChannelPipeline pipeline = ch.pipeline(); ?????????// 以("\n")为结尾分割的 解码器 ????????pipeline.addLast("framer", new DelimiterBasedFrameDecoder(8192, Delimiters.lineDelimiter())); ?????????// 字符串解码 和 编码 ????????pipeline.addLast("decoder", new StringDecoder()); ????????pipeline.addLast("encoder", new StringEncoder()); ?????????// 自己的逻辑Handler ????????pipeline.addLast("handler", new HelloServerHandler()); ????}}

public class HelloServerHandler extends SimpleChannelInboundHandler<String> { ????@Override ????protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception { ????????// 收到消息直接打印输出 ????????System.out.println(ctx.channel().remoteAddress() + " Say : " + msg); ?????????????????// 返回客户端消息 - 我已经接收到了你的消息 ????????ctx.writeAndFlush("Received your message !\n"); ????} ?????????/* ?????* ??????* 覆盖 channelActive 方法 在channel被启用的时候触发 (在建立连接的时候) ?????* ??????* channelActive 和 channelInActive 在后面的内容中讲述，这里先不做详细的描述 ?????* */ ????@Override ????public void channelActive(ChannelHandlerContext ctx) throws Exception { ?????????????????System.out.println("RamoteAddress : " + ctx.channel().remoteAddress() + " active !"); ?????????????????ctx.writeAndFlush( "Welcome to " + InetAddress.getLocalHost().getHostName() + " service!\n"); ?????????????????super.channelActive(ctx); ????}}