netty(二) 创建一个netty服务端和客户端

时间：2021-01-08 21:32:54

服务端

NettyServer

package com.zw.netty.config;

import com.zw.netty.channel.ServerInitializer;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;

/**
 * @author liuzw
 * @email liuzw1@hua-cloud.com.cn
 * @date 2018/12/20 20:39
 */
public class NettyServer {

    private final int port;

    public NettyServer(Integer port){
        this.port = port;
    }

    public void startServer(){
        EventLoopGroup bossGroup = new NioEventLoopGroup();
        EventLoopGroup workerGroup = new NioEventLoopGroup();
        try {
            ServerBootstrap b = new ServerBootstrap();
            b.group(bossGroup, workerGroup);
            b.channel(NioServerSocketChannel.class);
            b.option(ChannelOption.TCP_NODELAY, true);
            b.childHandler(new ServerInitializer());
            b.handler(new LoggingHandler(LogLevel.INFO));
            b.childOption(ChannelOption.AUTO_READ, true);

            // 服务器绑定端口监听
            ChannelFuture f = b.bind(port).sync();

            // 监听服务器关闭监听
            f.channel().closeFuture().sync();

        }catch (InterruptedException e){

        }finally {
            bossGroup.shutdownGracefully();
            workerGroup.shutdownGracefully();
        }
    }

    public static void main(String [] args){
        new NettyServer(8081).startServer();
    }
}

ChannelInitializer

package com.zw.netty.channel;

import com.zw.netty.handler.GpsHandler;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.*;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.util.CharsetUtil;

/**
 * @author liuzw
 * @email liuzw1@hua-cloud.com.cn
 * @date 2018/12/20 20:55
 */
public class ServerInitializer extends ChannelInitializer<SocketChannel> {

    @Override
     protected void initChannel(SocketChannel ch) throws Exception {

         ChannelPipeline pipeline = ch.pipeline();

         // 以("\n")为结尾分割的 解码器
//         pipeline.addLast("lenth",new FixedLengthFrameDecoder(7));
//         pipeline.addLast("framer", new DelimiterBasedFrameDecoder(8192, Delimiters.lineDelimiter()));
//        pipeline.addLast("framer",new DelimiterBasedFrameDecoder(8192, Unpooled.wrappedBuffer(new byte[] { '#' })));
//        pipeline.addLast(new LengthFieldBasedFrameDecoder(Integer.MAX_VALUE, 0, 4, 0, 4));
//        pipeline.addLast(new LengthFieldPrepender(4));

         // 字符串解码 和 编码
         pipeline.addLast("decoder", new StringDecoder());
         pipeline.addLast("encoder", new StringEncoder());

         // 自己的逻辑Handler
         pipeline.addLast("handler", new GpsHandler());
    }
}


ChannelHandler


package com.zw.netty.handler;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;

import java.net.InetAddress;
import java.nio.charset.Charset;
import java.time.LocalDateTime;

/**
 * @author liuzw
 * @email liuzw1@hua-cloud.com.cn
 * @date 2018/12/20 21:03
 */
public class GpsHandler extends SimpleChannelInboundHandler<String> {

    @Override
    protected void channelRead0(ChannelHandlerContext channelHandlerContext, String s) throws Exception {
        System.out.println("RamoteAddress : " + channelHandlerContext.channel().remoteAddress() + " active !");
        System.out.println(s);
//        channelHandlerContext.channel().writeAndFlush("from server；" + LocalDateTime.now());

    }

      /**
      * 覆盖 channelActive 方法 在channel被启用的时候触发 (在建立连接的时候)
      *
      * */
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        System.out.println("RamoteAddress : " + ctx.channel().remoteAddress() + " active !");

    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) { // (4)
        // 当出现异常就关闭连接
        ctx.close();
    }
}


客户端


ClientServer


package com.zw.netty;

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

/**
 * @author liuzw
 * @email liuzw1@hua-cloud.com.cn
 * @date 2018/12/21 9:49
 */
public class ClientServer {

    public static void main(String[] args) {
        EventLoopGroup eventLoopGroup = new NioEventLoopGroup();
        Bootstrap bootstrap = new Bootstrap();

        bootstrap.group(eventLoopGroup).channel(NioSocketChannel.class).handler(new MyClientInitializer());

        try {
            ChannelFuture channelFuture = bootstrap.connect("localhost", 9005).sync();
            channelFuture.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }finally {
            eventLoopGroup.shutdownGracefully();
        }
    }
}


ChannelInitializer


package com.zw.netty;

import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.FixedLengthFrameDecoder;
import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
import io.netty.handler.codec.LengthFieldPrepender;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.util.CharsetUtil;

/**
 * @author liuzw
 * @email liuzw1@hua-cloud.com.cn
 * @date 2018/12/21 9:50
 */
public class MyClientInitializer extends ChannelInitializer<SocketChannel> {

    @Override
    protected void initChannel(SocketChannel ch) throws Exception {
        ChannelPipeline pipeline = ch.pipeline();
//        pipeline.addLast(new FixedLengthFrameDecoder(7));
//        pipeline.addLast(new LengthFieldBasedFrameDecoder(Integer.MAX_VALUE, 0, 4, 0, 4));
//        pipeline.addLast(new LengthFieldPrepender(4));
        pipeline.addLast(new StringDecoder(CharsetUtil.UTF_8));
        pipeline.addLast(new StringEncoder(CharsetUtil.UTF_8));
        pipeline.addLast(new MyClientHandler());
    }

}


ChannelHandler


package com.zw.netty;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;

import java.time.LocalDateTime;

/**
 * @author liuzw
 * @email liuzw1@hua-cloud.com.cn
 * @date 2018/12/21 9:52
 */
public class MyClientHandler extends SimpleChannelInboundHandler<String> {

    @Override
    protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception {
        System.out.println(ctx.channel().remoteAddress());
        System.out.println("client output:" + msg);
        ctx.writeAndFlush("from client；" + LocalDateTime.now());

    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        super.exceptionCaught(ctx, cause);
        cause.printStackTrace();
        ctx.channel().close();
    }

    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        System.out.println("----------------------");
//        ctx.writeAndFlush("test#");
        ctx.writeAndFlush("test1  ");
//        ctx.writeAndFlush("test11111111111");
    }

}


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