服务端
package com.mypractice.netty.server; import java.net.InetSocketAddress; import io.netty.bootstrap.ServerBootstrap; import io.netty.channel.ChannelFuture; import io.netty.channel.ChannelOption; import io.netty.channel.EventLoopGroup; import io.netty.channel.nio.NioEventLoopGroup; import io.netty.channel.socket.nio.NioServerSocketChannel; public class EchoServer { private final int port; public EchoServer(int port) { this.port = port; } public static void main(String[] args) throws Exception { int port = Integer.parseInt("8888"); new EchoServer(port).start(); } public void start() throws Exception { EventLoopGroup boss = new NioEventLoopGroup(); EventLoopGroup worker = new NioEventLoopGroup(); try { ServerBootstrap b = new ServerBootstrap(); b.group(boss,worker) .channel(NioServerSocketChannel.class) .localAddress(new InetSocketAddress(port)) .childHandler(new CostomServerChannelInitializer()) //设置高低水位 .childOption(ChannelOption.WRITE_BUFFER_LOW_WATER_MARK, 1) .childOption(ChannelOption.WRITE_BUFFER_HIGH_WATER_MARK, 4); //绑定监听 ChannelFuture f = b.bind().sync(); System.out.println("正在监听..."); f.channel().closeFuture().sync(); } finally { //关闭EventLoopGroup,释放资源 boss.shutdownGracefully().sync(); worker.shutdownGracefully().sync(); } } }
package com.mypractice.netty.server; import io.netty.channel.ChannelInitializer; import io.netty.channel.socket.SocketChannel; public class CostomServerChannelInitializer extends ChannelInitializer<SocketChannel> { protected void initChannel(SocketChannel ch) throws Exception { // EchoServerHandler被标注为@Shareable,所以我们可以总是使用同样的实例 ch.pipeline().addLast(new EchoServerHandler()); } }
package com.mypractice.netty.server; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelFutureListener; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.ChannelInboundHandlerAdapter; import io.netty.channel.ChannelOption; import io.netty.util.CharsetUtil; public class EchoServerHandler extends ChannelInboundHandlerAdapter { @Override public void channelActive(ChannelHandlerContext ctx) throws Exception { System.out.println("Server 受到client连接:"+ctx.toString()); System.out.println(ctx.channel().config().getWriteBufferHighWaterMark()); System.out.println(ctx.channel().config().getWriteBufferLowWaterMark()); int size = ctx.channel().unsafe().outboundBuffer().size(); System.out.println("size1:" + size); super.channelActive(ctx); } @Override public void channelRead(ChannelHandlerContext ctx, Object msg) { ByteBuf in = (ByteBuf) msg; in.writeBytes("hello iam client".getBytes()); System.out.println("Server received: " + in.toString(CharsetUtil.UTF_8)); ctx.write(in); } @Override public void channelReadComplete(ChannelHandlerContext ctx) { ctx.writeAndFlush(Unpooled.EMPTY_BUFFER) .addListener(ChannelFutureListener.CLOSE);//将未决消息冲刷到远程节点,并且关闭该Channel } @Override public void channelWritabilityChanged(ChannelHandlerContext ctx) throws Exception { // TODO Auto-generated method stub System.out.println("channge:" +ctx.channel().isWritable()); int size = ctx.channel().unsafe().outboundBuffer().size(); System.out.println("size:" + size); super.channelWritabilityChanged(ctx); } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) { cause.printStackTrace(); ctx.close(); } }
客户端
package com.mypractice.netty.client; import java.net.InetSocketAddress; import io.netty.bootstrap.Bootstrap; import io.netty.channel.ChannelFuture; import io.netty.channel.ChannelInitializer; import io.netty.channel.EventLoopGroup; import io.netty.channel.nio.NioEventLoopGroup; import io.netty.channel.socket.SocketChannel; import io.netty.channel.socket.nio.NioSocketChannel; public class EchoClient { private final String host; private final int port; public EchoClient(String host, int port) { this.host = host; this.port = port; } public void start() throws Exception { EventLoopGroup worker = new NioEventLoopGroup(); try { Bootstrap b = new Bootstrap(); b.group(worker) .channel(NioSocketChannel.class) .remoteAddress(new InetSocketAddress(host, port)) .handler(new CostomChannelInitializer()); ChannelFuture f = b.connect().sync(); // 连接到远程节点,阻塞等待直到连接完成 f.channel().closeFuture().sync(); // 阻塞,直到Channel关闭 System.out.println("client close"); } finally { worker.shutdownGracefully().sync(); // 关闭线程池并且释放所有的资源 } } public static void main(String[] args) throws Exception { // if (args.length != 2) { // System.err.println( // "Usage: " + EchoClient.class.getSimpleName() + // " <host> <port>"); // return; // } String host = "127.0.0.1";// args[0]; int port = 8888;// Integer.parseInt(args[1]); new EchoClient(host, port).start(); } }
package com.mypractice.netty.client; import io.netty.channel.ChannelInitializer; import io.netty.channel.ChannelPipeline; import io.netty.channel.socket.SocketChannel; public class CostomChannelInitializer extends ChannelInitializer<SocketChannel> { @Override protected void initChannel(SocketChannel sc) throws Exception { ChannelPipeline pipeline = sc.pipeline(); pipeline.addLast(new EchoClientHandler()); } }
package com.mypractice.netty.client; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelHandler; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.SimpleChannelInboundHandler; import io.netty.util.CharsetUtil; //@Sharable //⇽--- 标记该类的实例可以被多个Channel共享 public class EchoClientHandler extends SimpleChannelInboundHandler<ByteBuf> { /** * 收到链接时出发 */ @Override public void channelActive(ChannelHandlerContext ctx) { System.out.println("rock!"); ctx.writeAndFlush(Unpooled.copiedBuffer("Netty rocks!", // ⇽--- 当被通知Channel是活跃的时候,发送一条消息 CharsetUtil.UTF_8)); } /** * 收到数据时触发 */ @Override public void channelRead0(ChannelHandlerContext ctx, ByteBuf in) { System.out.println("Client received: " + in.toString(CharsetUtil.UTF_8)); } @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { // TODO Auto-generated method stub ByteBuf in = (ByteBuf) msg; System.out.println("Client ##received: " + in.toString(CharsetUtil.UTF_8)); super.channelRead(ctx, msg); } @Override public void exceptionCaught(ChannelHandlerContext ctx, // ⇽--- 在发生异常时,记录错误并关闭Channel Throwable cause) { cause.printStackTrace(); ctx.close(); } }