筆記回顧

Server

package club.interview.io.netty.chat;

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.*;
import io.netty.channel.group.ChannelGroup;
import io.netty.channel.group.DefaultChannelGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
 
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.util.concurrent.GlobalEventExecutor;

/**
 * fixme channel組管理
 * @author QuCheng on 2020/8/17.
 */
public class NettyChatServerStudy1 {

    
 
public static void main(String[] args) {
        EventLoopGroup boss = new NioEventLoopGroup(1);
        EventLoopGroup worker = new NioEventLoopGroup();

        try {
            ServerBootstrap serverBootstrap = new ServerBootstrap();
            serverBootstrap.group(boss, worker)
                    .channel(NioServerSocketChannel.
 
class)
                    .childHandler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel ch) {
                            ChannelPipeline pipeline = ch.pipeline();
                            pipeline.addLast(new StringDecoder());
                            pipeline.addLast(new StringEncoder());
                            pipeline.addLast(new MyChatHandler());
                        }
                    });

            ChannelFuture channelFuture = serverBootstrap.bind(888).sync()
                    .addListener((ChannelFutureListener) future -> {
                        if (future.isSuccess()) {
                            System.out.println("Server is done !");
                        }
                    });
            channelFuture.channel().closeFuture().sync();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            boss.shutdownGracefully();
            worker.shutdownGracefully();
        }
    }

    static class MyChatHandler extends SimpleChannelInboundHandler<String> {

        static ChannelGroup channelGroup = new DefaultChannelGroup(GlobalEventExecutor.INSTANCE);

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

        @Override
        public void handlerAdded(ChannelHandlerContext ctx) {
            Channel channel = ctx.channel();
            channelGroup.add(channel);
            String msg = channel.remoteAddress() + " 加入群聊！";
            System.out.println("【Log】" + msg);
            channelGroup.writeAndFlush("【系統提醒】" + msg);
        }

        @Override
        public void handlerRemoved(ChannelHandlerContext ctx) {
            Channel channel = ctx.channel();
            String msg = channel.remoteAddress() + " 退出群聊！";
            System.out.println("【Log】" + msg);
            channelGroup.writeAndFlush("【系統提醒】" + msg);
        }

        @Override
        protected void channelRead0(ChannelHandlerContext ctx, String msg) {
            // 訊息轉發

            Channel channel = ctx.channel();

            channelGroup.forEach(c -> {
                String msg2;
                if (c == channel) {
                    msg2 = "【帥氣的我】" + "\n\t" + msg;
                } else {
                    msg2 = "【路人】" + c.remoteAddress() + " \n\t" + msg;
                }
                System.out.println("【Log】" + msg2);
                c.writeAndFlush(msg2);
            });
        }
    }
}

Client

package club.interview.io.netty.chat;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;

import java.util.Scanner;

/**
 * @author QuCheng on 2020/8/17.
 */
public class NettyChatClientStudy1 {

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


        try {


            Bootstrap bootstrap = new Bootstrap();

            bootstrap.group(group)
                    .channel(NioSocketChannel.class)
                    .handler(new ChannelInitializer<SocketChannel>() {
                        @Override
                        protected void initChannel(SocketChannel ch) throws Exception {
                            ch.pipeline()
                                    .addLast(new StringDecoder())
                                    .addLast(new StringEncoder())
                                    .addLast(new MyHandler());
                        }
                    });

            ChannelFuture channelFuture = bootstrap.connect("localhost", 888).sync()
                    .addListener(future -> {
                        if (future.isSuccess()) {
                            System.out.println("Client is ok !");
                        }
                    });

            // 發訊息
            Scanner scanner = new Scanner(System.in);
            Channel channel = channelFuture.channel();
            while (scanner.hasNextLine()) {
                channel.writeAndFlush(scanner.nextLine());
            }
            channel.closeFuture().sync();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            group.shutdownGracefully();
        }
    }

    static class MyHandler extends SimpleChannelInboundHandler<String> {

        @Override
        protected void channelRead0(ChannelHandlerContext ctx, String msg) throws Exception {
            System.out.println(msg);
        }
    }
}