netty -- 学习任务回声系统

回声系统(客户端发什么服务器响应什么)
服务端代码

import io.netty.bootstrap.ServerBootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.string.StringDecoder;
import lombok.extern.slf4j.Slf4j;

@Slf4j
public class HelloServer {
     
    public static void main(String[] args) {
     
        // 创建启动器
        new ServerBootstrap()
                // 创建EventLoop事件监听处理组
                .group(new NioEventLoopGroup())
                // 设置ServerSocketChannel的实现NioServerSocketChannel
                .channel(NioServerSocketChannel.class)
                // 设置处理器
                .childHandler(new ChannelInitializer<NioSocketChannel>() {
     
                    @Override
                    protected void initChannel(NioSocketChannel ch) throws Exception {
     
                        // 自定义处理器
                        ch.pipeline().addLast(new StringDecoder());
                        ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
     
                            // 监听读时间
                            @Override
                            public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
     
                                // 打印上一步转换好的字符串
                                log.debug("服务器打印---{}", msg.toString());
                                // 创建buf对象
                                ByteBuf buffer = ctx.alloc().buffer(200);
                                // 往客户端回应
                                ctx.channel().writeAndFlush(buffer.writeBytes(msg.toString().getBytes()));
                            }
                        });
                    }
                }).bind(8080); // 绑定的监听端口
    }
}

客户端代码

import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.string.StringEncoder;
import lombok.extern.slf4j.Slf4j;

import java.net.InetSocketAddress;
import java.nio.charset.Charset;
import java.util.Scanner;

@Slf4j
public class HelloClient {
     
    public static void main(String[] args) throws InterruptedException {
     
        NioEventLoopGroup group = new NioEventLoopGroup();
        //1 启动类
        Channel channel = new Bootstrap()
                // 2.添加EventLoop
                .group(group)
                // 3.选择客服端channel实现
                .channel(NioSocketChannel.class)
                // 4 添加处理器
                .handler(new ChannelInitializer<NioSocketChannel>() {
     
                    @Override
                    protected void initChannel(NioSocketChannel ch) throws Exception {
     
                        ch.pipeline().addLast(new StringEncoder());
                        ch.pipeline().addLast(new ChannelInboundHandlerAdapter() {
     
                            @Override
                            public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
     
                                ByteBuf byteBuf = (ByteBuf) msg;
                                log.debug("服务器返回---{}", byteBuf.toString(Charset.defaultCharset()));
                                // 释放buf对象
                                byteBuf.release();
                            }
                        });
                    }
                    // 连接地址
                }).connect(new InetSocketAddress("127.0.0.1", 8080))
                .sync()
                .channel();
        Scanner sc = new Scanner(System.in);
        while (true) {
     
            String name = sc.nextLine();
            if (name.equals("q")) {
     
                // 如果输入的是q 关闭服务器
                channel.close();
                log.debug("关闭服务器...");
                break;
            }
            // 发送输入的字符串
            channel.writeAndFlush(name);
        }
        ChannelFuture channelFuture = channel.closeFuture();
        // 等待异步的关闭结束
        channelFuture.sync();
        // 关闭任务组对象
        group.shutdownGracefully();
    }
}

测试通过 ,正常关闭