在公司最近用到netty，所以研究了下，写了个demo。
服务端如下：
package smu.gaoyi.netty; import io.netty.bootstrap.ServerBootstrap; import io.netty.channel.ChannelFuture; import io.netty.channel.ChannelInitializer; import io.netty.channel.ChannelOption; import io.netty.channel.EventLoopGroup; import io.netty.channel.nio.NioEventLoopGroup; import io.netty.channel.socket.SocketChannel; import io.netty.channel.socket.nio.NioServerSocketChannel; /** * Netty服务端 * * @author gaoyi * */ public class Server { private void bind(int port) { EventLoopGroup bossGroup = new NioEventLoopGroup(); EventLoopGroup workerGroup = new NioEventLoopGroup(); try { //服务端辅助启动类，用以降低服务端的开发复杂度 ServerBootstrap bootstrap = new ServerBootstrap(); bootstrap.group(bossGroup, workerGroup) //实例化ServerSocketChannel .channel(NioServerSocketChannel.class) //设置ServerSocketChannel的TCP参数 .option(ChannelOption.SO_BACKLOG, 1024) .childHandler(new ChildChannelHandler()); // ChannelFuture：代表异步I/O的结果 ChannelFuture f = bootstrap.bind(port).sync(); f.channel().closeFuture().sync(); } catch (InterruptedException e) { System.out.println("启动netty服务异常"); e.printStackTrace(); } finally { workerGroup.shutdownGracefully(); bossGroup.shutdownGracefully(); } } private class ChildChannelHandler extends ChannelInitializer<SocketChannel> { @Override protected void initChannel(SocketChannel ch) throws Exception { //handler ch.pipeline().addLast(new ServerHandler()); } } public static void main(String[] args) { int port = 8888; new Server().bind(port); } } 服务端的handler： package smu.gaoyi.netty; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.ChannelInboundHandlerAdapter; /** * Handles a server-side channel. * @author yi.gao * */ public class ServerHandler extends ChannelInboundHandlerAdapter{ @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { ByteBuf buf = (ByteBuf)msg; byte[] bytes = new byte[buf.readableBytes()]; buf.readBytes(bytes); String message = new String(bytes, "UTF-8"); System.out.println("服务端收到的消息： " + message); //向客户端写数据 String response = "hello client"; ByteBuf buffer = Unpooled.copiedBuffer(response.getBytes()); ctx.write(buffer);//写入缓冲数组 } @Override public void channelReadComplete(ChannelHandlerContext ctx) throws Exception { System.out.println("channelReadComplete..."); ctx.flush();//将缓冲区数据写入SocketChannel } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { System.out.println("exceptionCaught..."); } } 客户端： package smu.gaoyi.netty; 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 Client { public void connect(String host, int port) throws Exception { EventLoopGroup group = new NioEventLoopGroup(); try { Bootstrap bootstrap = new Bootstrap(); bootstrap.group(group) .channel(NioSocketChannel.class) .handler(new ChannelInitializer<SocketChannel>() { @Override protected void initChannel(SocketChannel ch) throws Exception { ch.pipeline().addLast(new ClientHandler()); } }); ChannelFuture future = bootstrap.connect(host, port).sync(); future.channel().closeFuture().sync(); } finally { group.shutdownGracefully(); } } public static void main(String[] args) throws Exception { new Client().connect("localhost", 8888); } } 客户端的handler： package smu.gaoyi.netty; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.ChannelInboundHandlerAdapter; public class ClientHandler extends ChannelInboundHandlerAdapter{ private final ByteBuf byteBuf; public ClientHandler() { byte[] bytes = "i love you".getBytes(); byteBuf = Unpooled.buffer(bytes.length); byteBuf.writeBytes(bytes);//写入buffer } @Override public void channelActive(ChannelHandlerContext ctx) throws Exception { //向服务端发送数据 ctx.writeAndFlush(byteBuf); } @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { //读取服务端发过来的数据 ByteBuf buf = (ByteBuf)msg; byte[] bytes = new byte[buf.readableBytes()]; buf.readBytes(bytes); String message = new String(bytes, "UTF-8"); System.out.println("客户端收到的消息： " + message); } }
