Hadoop25---netty，单个handler

package cn.itcast_03_netty.sendstring.client;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;import java.net.InetSocketAddress;import cn.itcast_03_netty.sendobject.coder.PersonEncoder;/** * ? 连接服务器 ? 写数据到服务器 ? 等待接受服务器返回相同的数据 ? 关闭连接 * ?* @author wilson * */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 nioEventLoopGroup = null; ???????try { ???????????//不用创建线程池了，内部就有线程池。netty是基于nio开发的。 ???????????// 客户端引导类，启动的。 ???????????Bootstrap bootstrap = new Bootstrap(); ???????????// EventLoopGroup可以理解为是一个线程池的组，这个线程池用来处理连接、接受数据、发送数据 ???????????nioEventLoopGroup = new NioEventLoopGroup(); ???????????bootstrap.group(nioEventLoopGroup)//多线程处理 ???????????????????.channel(NioSocketChannel.class)//指定通道类型为NioServerSocketChannel，一种异步模式，OIO阻塞模式为OioServerSocketChannel ???????????????????.remoteAddress(new InetSocketAddress(host, port))//地址 ???????????????????//in handler是进来的，out handler是出去的， ???????????????????.handler(new ChannelInitializer<SocketChannel>() {//业务处理类 ???????????????????????????????@Override ???????????????????????????????protected void initChannel(SocketChannel ch) ???????????????????????????????????????throws Exception { ???????????????????????????????????ch.pipeline().addLast(new EchoClientHandler());//注册handler ???????????????????????????????} ???????????????????????????}); ???????????// 链接服务器 ???????????ChannelFuture channelFuture = bootstrap.connect().sync(); ???????????channelFuture.channel().closeFuture().sync(); ???????} finally { ???????????nioEventLoopGroup.shutdownGracefully().sync(); ???????} ???} ???public static void main(String[] args) throws Exception { ???????new EchoClient("localhost", 20000).start();//不是想出的start而是普通的方法 ???}}

package cn.itcast_03_netty.sendstring.client;import io.netty.buffer.ByteBuf;import io.netty.buffer.Unpooled;import io.netty.channel.ChannelHandlerContext;import io.netty.channel.SimpleChannelInboundHandler;import cn.itcast_03_netty.sendobject.bean.Person;public class EchoClientHandler extends SimpleChannelInboundHandler<ByteBuf> { ???// 客户端连接服务器后被调用 ???@Override ???public void channelActive(ChannelHandlerContext ctx) throws Exception { ???????System.out.println("客户端连接服务器，开始发送数据……"); ???????byte[] req = "QUERY TIME ORDER".getBytes();//消息 ???????//nio的buffer ???????ByteBuf firstMessage = Unpooled.buffer(req.length);//发送类 ???????firstMessage.writeBytes(req);//发送 ???????ctx.writeAndFlush(firstMessage);//flush ???} ???// ? 从服务器接收到数据后调用 ???@Override ???protected void channelRead0(ChannelHandlerContext ctx, ByteBuf msg) ???????????throws Exception { ???????System.out.println("client 读取server数据.."); ???????// 服务端返回消息后 ???????ByteBuf buf = (ByteBuf) msg; ???????byte[] req = new byte[buf.readableBytes()]; ???????buf.readBytes(req); ???????String body = new String(req, "UTF-8"); ???????System.out.println("服务端数据为 :" + body); ???} ???// ? 发生异常时被调用 ???@Override ???public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) ???????????throws Exception { ???????System.out.println("client exceptionCaught.."); ???????// 释放资源 ???????ctx.close(); ???}}

package cn.itcast_03_netty.sendstring.server;import io.netty.bootstrap.ServerBootstrap;import io.netty.channel.Channel;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.nio.NioServerSocketChannel;import cn.itcast_03_netty.sendobject.coder.PersonDecoder;/** * ? 配置服务器功能，如线程、端口 ? 实现服务器处理程序，它包含业务逻辑，决定当有一个请求连接或接收数据时该做什么 * ?* @author wilson * */public class EchoServer { ???private final int port; ???public EchoServer(int port) { ???????this.port = port; ???} ???public void start() throws Exception { ???????EventLoopGroup eventLoopGroup = null; ???????try { ???????????//server端引导类 ???????????ServerBootstrap serverBootstrap = new ServerBootstrap(); ???????????//连接池处理数据 ???????????eventLoopGroup = new NioEventLoopGroup(); ???????????//装配bootstrap ???????????serverBootstrap.group(eventLoopGroup) ???????????.channel(NioServerSocketChannel.class)//指定通道类型为NioServerSocketChannel，一种异步模式，OIO阻塞模式为OioServerSocketChannel ???????????.localAddress("localhost",port)//设置InetSocketAddress让服务器监听某个端口已等待客户端连接。 ???????????.childHandler(new ChannelInitializer<Channel>() {//设置childHandler执行所有的连接请求 ???????????????@Override ???????????????protected void initChannel(Channel ch) throws Exception { ???????????????????ch.pipeline().addLast(new EchoServerHandler());//注册handler ???????????????} ???????????????????}); ???????????// 最后绑定服务器等待直到绑定完成，调用sync()方法会阻塞直到服务器完成绑定,然后服务器等待通道关闭，因为使用sync()，所以关闭操作也会被阻塞。 ???????????ChannelFuture channelFuture = serverBootstrap.bind().sync(); ???????????System.out.println("开始监听，端口为：" + channelFuture.channel().localAddress()); ???????????channelFuture.channel().closeFuture().sync(); ???????} finally { ???????????eventLoopGroup.shutdownGracefully().sync(); ???????} ???} ???public static void main(String[] args) throws Exception { ???????new EchoServer(20000).start(); ???}}

package cn.itcast_03_netty.sendstring.server;import io.netty.buffer.ByteBuf;import io.netty.buffer.Unpooled;import io.netty.channel.ChannelHandlerContext;import io.netty.channel.ChannelInboundHandlerAdapter;import java.util.Date;import cn.itcast_03_netty.sendobject.bean.Person;public class EchoServerHandler extends ChannelInboundHandlerAdapter { ???@Override ???public void channelRead(ChannelHandlerContext ctx, Object msg) ???????????throws Exception { ???????System.out.println("server 读取数据……"); ???????//读取数据 ???????ByteBuf buf = (ByteBuf) msg; ???????byte[] req = new byte[buf.readableBytes()]; ???????buf.readBytes(req); ???????String body = new String(req, "UTF-8"); ???????System.out.println("接收客户端数据:" + body); ???????//向客户端写数据 ???????System.out.println("server向client发送数据"); ???????String currentTime = new Date(System.currentTimeMillis()).toString(); ???????ByteBuf resp = Unpooled.copiedBuffer(currentTime.getBytes()); ???????ctx.write(resp); ???????????} ???@Override ???public void channelReadComplete(ChannelHandlerContext ctx) throws Exception { ???????System.out.println("server 读取数据完毕.."); ???????ctx.flush();//刷新后才将数据发出到SocketChannel ???} ???@Override ???public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) ???????????throws Exception { ???????cause.printStackTrace(); ???????ctx.close(); ???}}