TCP-IP学习笔记五：Netty使用--简单通信编程1

TCP/IP学习笔记五：Netty使用–简单通信编程1

标签（空格分隔）：Netty 网络编程

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Netty的简单使用示例。

编程思路按照注释进行就可以了。

一、导入Netty的jar

最先版本：netty-all-5.0.0.Alpha2.jar

二、服务器端

package com.netty.demo1.server;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;

/**
 * Netty NIO 服务器端
 * @author MOTUI
 *
 */
public class NettyNIOServer {

    public static void main(String[] args) throws InterruptedException {

        //1.创建NIOServerSocketChannel的服务引导
        ServerBootstrap serverBootstrap = new ServerBootstrap();
        //2.创建线程池 boss(请求转发) worker(IO事件处理)
        NioEventLoopGroup boss = new NioEventLoopGroup();
        NioEventLoopGroup worker = new NioEventLoopGroup();
        //3.绑定线程
        serverBootstrap.group(boss, worker);
        //4.设置ServerSocket服务类
        serverBootstrap.channel(NioServerSocketChannel.class);
        //5.绑定IO处理事件
        serverBootstrap.childHandler(new ServerChannelInitializer());
        //6.绑定服务端口
        System.out.println("服务器监听8989端口");
        ChannelFuture future = serverBootstrap.bind(8989).sync();
        //等待服务器被关闭
        future.channel().closeFuture().sync();

        //释放线程资源
        worker.shutdownGracefully();
        boss.shutdownGracefully();  

    }   
}

注册IO事件处理类

package com.netty.demo1.server;

import io.netty.channel.ChannelInitializer;
import io.netty.channel.socket.SocketChannel;

public class ServerChannelInitializer extends ChannelInitializer<SocketChannel> {
    /**
     * 注册IO事件处理类
     */
    @Override
    protected void initChannel(SocketChannel ch) throws Exception {

        ch.pipeline().addLast(new ServerRequestResponseHander());
    }
}

IO事件处理类

package com.netty.demo1.server;

import java.util.Date;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;
import io.netty.util.CharsetUtil;

/**
 * 事件处理类
 * @author MOTUI
 *
 */
public class ServerRequestResponseHander extends ChannelHandlerAdapter {
    /**
     * 异常调用
     */
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
            throws Exception {
        System.out.println("发生异常了···异常信息："+cause.getMessage());

    }

    /**
     * 读数据调用
     */
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg)
            throws Exception {
        ByteBuf buffer=(ByteBuf) msg;
        System.out.println("服务器接收到的数据："+buffer.toString(CharsetUtil.UTF_8));
        //ctx.writeAndFlush(msg);//写回响应
        //响应一个时间
        ByteBuf buf=ctx.alloc().buffer(1024);
        buf.writeBytes(new Date().toString().getBytes());
        ctx.writeAndFlush(buf);

    }
}

客户端

package com.netty.demo1.client;

import java.net.InetSocketAddress;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioSocketChannel;

/**
 * Netty NIO 客户端
 * @author MOTUI
 *
 */
public class NettyNIOClient {

    public static void main(String[] args) throws InterruptedException {

        //1.创建NIOSocketChannel的服务引导
        Bootstrap bootstrap = new Bootstrap();
        //2.创建线程池 worker(IO事件处理)
        NioEventLoopGroup boss = new NioEventLoopGroup();
        //3.关联线程池
        bootstrap.group(boss);
        //4.设置NioSocketChannel
        bootstrap.channel(NioSocketChannel.class);
        //5.绑定IO处理事件
        bootstrap.handler(new ClientChannelInitializer());
        //6.链接服务器
        ChannelFuture future = bootstrap.connect(new InetSocketAddress("192.168.0.117", 8989));

        //等待关闭连接
        future.channel().closeFuture().sync();

        //释放资源
        boss.shutdownGracefully();
    }   
}

客户端注册IO事件处理类

package com.netty.demo1.client;

import io.netty.channel.ChannelInitializer;
import io.netty.channel.socket.SocketChannel;

public class ClientChannelInitializer extends ChannelInitializer<SocketChannel> {
    /**
     * 注册IO事件处理类
     */
    @Override
    protected void initChannel(SocketChannel ch) throws Exception {

        ch.pipeline().addLast(new ClientRequestResponseHander());
    }
}

客户端IO事件处理类

package com.netty.demo1.client;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;
import io.netty.util.CharsetUtil;

/**
 * 事件处理类
 * @author MOTUI
 *
 */
public class ClientRequestResponseHander extends ChannelHandlerAdapter {
    /**
     * 异常调用
     */
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
            throws Exception {
        System.out.println("发生异常了···异常信息："+cause.getMessage());

    }

    /**
     * 发送请求
     */
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        //创建ByteBuf

        ByteBuf buf = Unpooled.buffer(1024);
        buf.writeBytes("你好，我好，大家好！".getBytes());
        ctx.writeAndFlush(buf);

    }
    /**
     * 读数据调用
     */
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg)
            throws Exception {

        ByteBuf buffer=(ByteBuf) msg;
        System.out.println("客户端收到:"+buffer.toString(CharsetUtil.UTF_8));

        //关闭链接
        ctx.close();
    }
}

总结：

    编程思路按照官方文档进行编码，简单类型的传递没有太大的问题，对于对象类型数据的传输会存在一些问题（下篇介绍对象类型的传输）。