主要思路：

* 服务器每隔两秒发送一次服务器的时间

* 客户端接收服务器端数据，打印出服务器的时间

服务器端代码

package netty.time.server;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;
import io.netty.handler.timeout.ReadTimeoutHandler;
import io.netty.handler.timeout.WriteTimeoutHandler;/*** Created with IntelliJ IDEA.* User: ASUS* Date: 14-5-7* Time: 上午10:10* To change this template use File | Settings | File Templates.*/
public class TimeServer {public static void main(String[] args) {// EventLoop 代替原来的 ChannelFactoryEventLoopGroup bossGroup = new NioEventLoopGroup();EventLoopGroup workerGroup = new NioEventLoopGroup();try {ServerBootstrap serverBootstrap = new ServerBootstrap();serverBootstrap.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class).childHandler(new ChannelInitializer<SocketChannel>() {@Overridepublic void initChannel(SocketChannel ch) throws Exception {ch.pipeline().addLast(new TimeServerHandler(),new WriteTimeoutHandler(10),//控制写入超时10秒构造参数10表示如果持续10秒钟都没有数据写了，那么就超时。new ReadTimeoutHandler(10));}}).option(ChannelOption.SO_KEEPALIVE, true);ChannelFuture f = serverBootstrap.bind(9090).sync();f.channel().closeFuture().sync();} catch (InterruptedException e) {} finally {workerGroup.shutdownGracefully();bossGroup.shutdownGracefully();}}
}

package netty.time.server;import io.netty.buffer.ByteBuf;
import io.netty.channel.*;public class TimeServerHandler extends ChannelInboundHandlerAdapter {//ChannelHandlerContext通道处理上下文@Overridepublic void channelActive(final ChannelHandlerContext ctx) throws InterruptedException { // (1)while (true) {ByteBuf time = ctx.alloc().buffer(4); //为ByteBuf分配四个字节time.writeInt((int) (System.currentTimeMillis() / 1000L + 2208988800L));ctx.writeAndFlush(time); // (3)Thread.sleep(2000);}}@Overridepublic void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {cause.printStackTrace();ctx.close();}
}

客户端代码

package netty.time.server;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;/*** 服务器每隔两秒发送一次服务器的时间* 客户端接收服务器端数据，打印出服务器的时间*/
public class TimeClient {public static void main(String[] args) throws Exception {EventLoopGroup workerGroup = new NioEventLoopGroup();try {Bootstrap b = new Bootstrap(); // (1)b.group(workerGroup); // (2)b.channel(NioSocketChannel.class); // (3)b.option(ChannelOption.SO_KEEPALIVE, true); // (4)b.handler(new ChannelInitializer<SocketChannel>() {@Overridepublic void initChannel(SocketChannel ch) throws Exception {ch.pipeline().addLast(new TimeClientHandler());}});// Start the client.ChannelFuture f = b.connect("127.0.0.1", 9090).sync(); // (5)// Wait until the connection is closed.f.channel().closeFuture().sync();} finally {workerGroup.shutdownGracefully();}}
}

package netty.time.server;import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;import java.util.Date;public class TimeClientHandler extends ChannelInboundHandlerAdapter {@Overridepublic void channelRead(ChannelHandlerContext ctx, Object msg) {ByteBuf m = (ByteBuf) msg;try {long currentTimeMillis = (m.readUnsignedInt() - 2208988800L) * 1000L;System.out.println(new Date(currentTimeMillis));} finally {m.release();}}@Overridepublic void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {cause.printStackTrace();ctx.close();}
}

运行结果：

Sun Jun 22 18:40:42 CST 2014

Sun Jun 22 18:40:44 CST 2014

Sun Jun 22 18:40:46 CST 2014

Sun Jun 22 18:40:48 CST 2014

Sun Jun 22 18:40:50 CST 2014

Sun Jun 22 18:40:52 CST 2014

Sun Jun 22 18:40:54 CST 2014

Sun Jun 22 18:40:56 CST 2014

.................................

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