netty之hello-world

netty之hello-world

服务端

package com.netty;

import io.netty.bootstrap.ServerBootstrap;
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;

/**
 * @author wj
 * @date 2021.10.27 14:59
 */
public class HelloServer {

    public static void main(String[] args) {

        //1.启动器，负责组装netty 组件，启动服务器
        new ServerBootstrap()
                //2. BossEventLoop WorkerEventLoop(selector thread) group 组
                .group(new NioEventLoopGroup())
                //3.选择服务器的serverSocketChannel 实现
                .channel(NioServerSocketChannel.class)
                //4.boss 负责处理连接 worker(child) 负责处理读写 决定了worker(child) 能执行那些操作 (handler)
                .childHandler(
                        //5.channel 代表和客户端尽心那个数据读写的通道 Initializer 初始化，负责添加别的 handler
                        new ChannelInitializer<NioSocketChannel>() {
                    @Override
                    protected void initChannel(NioSocketChannel ch) throws Exception {
                        //6.添加具体的handler
                        ch.pipeline().addLast(new StringDecoder()); //将ByteBuf转换为字符串
                        ch.pipeline().addLast(new ChannelInboundHandlerAdapter(){ //自定义handler
                            //读事件
                            @Override
                            public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
                                //打印上一步转换好的字符串
                                System.out.println(msg);
                            }
                        });
                    }
                })
                //7.绑定监听端口
                .bind(8080);
    }
}

客户端

package com.netty;

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

import java.net.InetSocketAddress;

/**
 * @author wj
 * @date 2021.10.27 15:15
 */
public class HelloClient {

    public static void main(String[] args) throws InterruptedException {
        //1.创建启动类
        new Bootstrap()
                //2.添加EventLoop
                .group(new NioEventLoopGroup())
                //3.选择客户端channel执行
                .channel(NioSocketChannel.class)
                //4.添加处理器
                .handler(new ChannelInitializer<NioSocketChannel>() {
                    @Override //在连接建立后被调用
                    protected void initChannel(NioSocketChannel ch) throws Exception {
                        ch.pipeline().addLast(new StringEncoder());
                    }
                })
                //5.连接到服务器
                .connect(new InetSocketAddress("127.0.0.1",8080))
                .sync() //阻塞方法，直到连接建立
                .channel()
                //6.向服务器发送数据
                .writeAndFlush("hello world");
    }
}