1、Netty软件包下载:http://netty.io/downloads.html,本示例基于netty-5.0.0.Alpha2.tar.bz2
2、搭建Netty应用工程
使用eclipse创建一个java工程,新建lib文件夹并将netty-all-5.0.0.Alpha2.jar复制到该文件夹下,然后将jar引入工程。
3、Netty服务端开发
TimeServer.java
package com.neety; 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; public class TimeServer { public void bind(int port)throws Exception{ //配置服务端Nio线程组 EventLoopGroup bossGroup = new NioEventLoopGroup(); EventLoopGroup workerGroup = new NioEventLoopGroup(); try{ ServerBootstrap b = new ServerBootstrap(); b.group(bossGroup, workerGroup) .channel(NioServerSocketChannel.class) .option(ChannelOption.SO_BACKLOG, 1024) //.childHandler(new TimeServerHandler()); .childHandler(new ChildChannelHandler()); //绑定端口,同步等待成功 ChannelFuture f = b.bind(port).sync(); //等待服务端监听端口关闭 f.channel().closeFuture().sync(); }finally{ //退出时释放资源 bossGroup.shutdownGracefully(); workerGroup.shutdownGracefully(); } } private class ChildChannelHandler extends ChannelInitializer<SocketChannel>{ @Override protected void initChannel(SocketChannel channel) throws Exception { channel.pipeline().addLast(new TimeServerHandler()); } } public static void main(String[] args) throws Exception{ int port = 8083; if(args!=null && args.length > 0){ port = Integer.valueOf(args[0]); } new TimeServer().bind(port); } }
TimeServerHandler.java
package com.neety; import java.util.Date; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelHandlerAdapter; import io.netty.channel.ChannelHandlerContext; public class TimeServerHandler extends ChannelHandlerAdapter { @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { //super.channelRead(ctx, msg); ByteBuf buf = (ByteBuf) msg; byte [] req = new byte[buf.readableBytes()]; buf.readBytes(req); String body = new String(req,"UTF-8"); System.out.println("The time server receive order:"+body); String currentTime = "query time order".equalsIgnoreCase(body)?new Date( System.currentTimeMillis()).toString():"bad order"; ByteBuf resp = Unpooled.copiedBuffer(currentTime.getBytes()); ctx.write(resp); } @Override public void channelReadComplete(ChannelHandlerContext ctx) throws Exception { //super.channelReadComplete(ctx); ctx.flush(); } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { //super.exceptionCaught(ctx, cause); ctx.close(); } }
4、Netty客户端开发
TimeClient.java
package com.neety; import io.netty.bootstrap.Bootstrap; 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.NioSocketChannel; public class TimeClient { public void connect(int port,String host)throws Exception{ //配置客户端NIO线程组 EventLoopGroup group = new NioEventLoopGroup(); try{ Bootstrap b = new Bootstrap(); b.group(group).channel(NioSocketChannel.class) .option(ChannelOption.TCP_NODELAY, true) .handler(new ChannelInitializer<SocketChannel>() { protected void initChannel(SocketChannel ch) throws Exception { ch.pipeline().addLast(new TimeClientHandler()); }; }); //发起异步连接操作 ChannelFuture f = b.connect(host,port).sync(); //等待客户端链路关闭 f.channel().closeFuture().sync(); }finally{ //退出,释放资源 group.shutdownGracefully(); } } public static void main(String[] args)throws Exception { int port = 8083; if(args!=null && args.length > 0){ port = Integer.valueOf(args[0]); } new TimeClient().connect(port, "127.0.0.1"); } }
TimeClientHandler.java
package com.neety; import java.util.logging.Logger; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelHandlerAdapter; import io.netty.channel.ChannelHandlerContext; /** * * @author Administrator * */ public class TimeClientHandler extends ChannelHandlerAdapter { private static final Logger logger = Logger.getLogger(TimeClientHandler.class.getName()); private final ByteBuf firstMessage; public TimeClientHandler() { byte [] req = "query time order".getBytes(); firstMessage = Unpooled.buffer(req.length); firstMessage.writeBytes(req); } @Override public void channelActive(ChannelHandlerContext ctx) throws Exception { //super.channelActive(ctx); ctx.writeAndFlush(firstMessage); } @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { //super.channelRead(ctx, msg); ByteBuf buf = (ByteBuf)msg; byte [] req = new byte[buf.readableBytes()]; buf.readBytes(req); String body = new String(req, "UTF-8"); System.out.println("now is :"+body); } @Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception { //super.exceptionCaught(ctx, cause); logger.warning("unexpected exception from downstream:"+ cause.getMessage()); ctx.close(); } }
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