Netty入门初级服务端客户端编写

1.创建maven项目并引入依赖
2.编写服务端代码
3.编写具体IO处理类

1.创建maven项目并引入依赖

<dependency>
    <groupId>io.netty</groupId>
    <artifactId>netty-all</artifactId>
    <version>5.0.0.Alpha2</version>
</dependency>

2.编写服务端代码

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
/**
 * @author 冯铁城 [17615007230@163.com]
 * @date 2022-05-09 19:11:57
 * @describe: 时间服务器服务端
 */
public class TimeServer {
    public static void main(String[] args) {
        int port = 8080;
        if(null != args && 0 < args.length){
            port = Integer.parseInt(args[0]);
        }
        new TimeServer().bind(port);
    }
    public void bind(int port) {
        //1.创建线程组用于接受服务端链接
        NioEventLoopGroup bossGroup = new NioEventLoopGroup();
        //2.创建线程组用户socketChannel读写
        NioEventLoopGroup workGroup = new NioEventLoopGroup();
        try {
            //3.创建服务端
            ServerBootstrap server = new ServerBootstrap();
            server.group(bossGroup, workGroup)
                    .channel(NioServerSocketChannel.class)
                    .option(ChannelOption.SO_BACKLOG, 1024)
                    .childHandler(new ChildChannelHandler());
            //3.绑定端口,开启同步等
            ChannelFuture sync = server.bind(port).sync();
            System.out.println("服务端已启动!");
            //4.等待服务端监听端口关闭
            sync.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }finally {
            bossGroup.shutdownGracefully();
            workGroup.shutdownGracefully();
        }
    }
    private class ChildChannelHandler extends ChannelInitializer<SocketChannel>{
        @Override
        protected void initChannel(SocketChannel socketChannel) throws Exception {
            socketChannel.pipeline().addLast(new TimeServerHandler());
        }
    }
}

创建用于接收客户端链接线程组、负责socketIO的线程组
开启Netty服务端
服务端配置线程组、渠道、配置TCP参数、定义IO事件处理类
同步绑定端口开启
最终优雅退出线程
IO时间处理类添加具体IO处理类
3.编写具体IO处理类
```java import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelHandlerAdapter; import io.netty.channel.ChannelHandlerContext;

import java.util.Scanner;

/**

@author 冯铁城 [17615007230@163.com]
@date 2022-05-09 20:41:33

@describe: 时间服务器服务端 */ public class TimeServerHandler extends ChannelHandlerAdapter {

private static final Scanner SCANNER = new Scanner(System.in);

@Override public void channelActive(ChannelHandlerContext ctx) throws Exception {

 System.out.println("服务端已与" + ctx.channel().id() + "建立链接");

}

@Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {

 //1.读取消息为字节数组
 ByteBuf buf = (ByteBuf) msg;
 byte[] bytes = new byte[buf.readableBytes()];
 buf.readBytes(bytes);
 //2.字符串判定
 String body = new String(bytes, "UTF-8");
 System.out.println("收到" + ctx.channel().id() + "渠道的请求:" + body);
 //3.定义返回结果
 System.out.println("请输入响应信息");
 String responseMessage = SCANNER.nextLine();
 //4.相应数据
 ByteBuf response = Unpooled.copiedBuffer(responseMessage.getBytes());
 ctx.write(response);

}

@Override public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {

 ctx.flush();

}

@Override public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {

 ctx.close();

} } ```

继承ChannelHandlerAdapter类
重写channelActive方法，当客户端或服务端建立链接时，触发此方法
重写channelRead方法，当客户端

Netty入门 初级服务端客户端编写

1.创建maven项目并引入依赖

2.编写服务端代码

3.编写具体IO处理类