SpringBoot + Netty初體驗

一，引入pom依賴

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
    </dependency>

    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>io.netty</groupId>
        <artifactId>netty-all</artifactId>
        <version>4.1.45.Final</version>
    </dependency>
</dependencies>
            

二，搭建netty-server服務端

package com.example.netty.server;

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 lombok.extern.slf4j.Slf4j;

import java.net.InetSocketAddress;

/**
 * 服務啟動監聽器
 **/
@Slf4j
public class NettyServer {

    public void start(InetSocketAddress socketAddress) {
        //new 一個主線程組
        EventLoopGroup bossGroup = new NioEventLoopGroup(1);
        //new 一個工作線程組
        EventLoopGroup workGroup = new NioEventLoopGroup(200);
        ServerBootstrap bootstrap = new ServerBootstrap()
                .group(bossGroup, workGroup)
                .channel(NioServerSocketChannel.class)
                .childHandler(new ServerChannelInitializer())
                .localAddress(socketAddress)
                //設置隊列大小
                .option(ChannelOption.SO_BACKLOG, 1024)
                // 兩小時內沒有數據的通信時,TCP會自動發送一個活動探測數據報文
                .childOption(ChannelOption.SO_KEEPALIVE, true);
        //綁定端口,開始接收進來的連接
        try {
            ChannelFuture future = bootstrap.bind(socketAddress).sync();
            log.info("服務器啟動開始監聽端口: {}", socketAddress.getPort());
            future.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            //關閉主線程組
            bossGroup.shutdownGracefully();
            //關閉工作線程組
            workGroup.shutdownGracefully();
        }
    }
}

package com.example.netty.server;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import lombok.extern.slf4j.Slf4j;

/**
 * netty服務端處理器
 **/
@Slf4j
public class NettyServerHandler extends ChannelInboundHandlerAdapter {
    /**
     * 客戶端連接會觸發
     */
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        log.info("Channel active......");
    }

    /**
     * 客戶端發消息會觸發
     */
    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        log.info("服務器收到消息: {}", msg.toString());
        ctx.write("你也好哦");
        ctx.flush();
    }

    /**
     * 發生異常觸發
     */
    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        cause.printStackTrace();
        ctx.close();
    }
}

package com.example.netty.server;

import io.netty.channel.ChannelInitializer;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;
import io.netty.util.CharsetUtil;

import io.netty.channel.socket.SocketChannel;

/**
 * netty服務初始化器
 **/
public class ServerChannelInitializer extends ChannelInitializer<SocketChannel> {
    @Override
    protected void initChannel(SocketChannel socketChannel) throws Exception {
        //添加編解碼
        socketChannel.pipeline().addLast("decoder", new StringDecoder(CharsetUtil.UTF_8));
        socketChannel.pipeline().addLast("encoder", new StringEncoder(CharsetUtil.UTF_8));
        socketChannel.pipeline().addLast(new NettyServerHandler());
    }
}

package com.example.netty.server;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

import java.net.InetSocketAddress;

@SpringBootApplication
public class NettyServerApplication {

    public static void main(String[] args) {
        SpringApplication.run(NettyServerApplication.class, args);
        //啟動服務端
        NettyServer nettyServer = new NettyServer();
        nettyServer.start(new InetSocketAddress("127.0.0.1", 8090));
    }

}

三，搭建netty-client客戶端

package com.example.netty.client;

import io.netty.bootstrap.Bootstrap;
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.NioSocketChannel;
import lombok.extern.slf4j.Slf4j;

@Slf4j
public class NettyClient {

    public void start() {
        EventLoopGroup group = new NioEventLoopGroup();
        Bootstrap bootstrap = new Bootstrap()
                .group(group)
                //該參數的作用就是禁止使用Nagle算法，使用於小數據即時傳輸
                .option(ChannelOption.TCP_NODELAY, true)
                .channel(NioSocketChannel.class)
                .handler(new NettyClientInitializer());

        try {
            ChannelFuture future = bootstrap.connect("127.0.0.1", 8090).sync();
            log.info("客戶端成功....");
            //發送消息
            future.channel().writeAndFlush("你好啊");
            // 等待連接被關閉
            future.channel().closeFuture().sync();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }finally {
            group.shutdownGracefully();
        }
    }
}

package com.example.netty.client;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import lombok.extern.slf4j.Slf4j;

/**
 * 客戶端處理器
 **/
@Slf4j
public class NettyClientHandler extends ChannelInboundHandlerAdapter {
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {
        log.info("客戶端Active .....");
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
        log.info("客戶端收到消息: {}", msg.toString());
    }

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

package com.example.netty.client;

import io.netty.channel.ChannelInitializer;
import io.netty.channel.socket.SocketChannel;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;

/**
 * 客戶端初始化器
 **/
public class NettyClientInitializer extends ChannelInitializer<SocketChannel> {
    @Override
    protected void initChannel(SocketChannel socketChannel) throws Exception {
        socketChannel.pipeline().addLast("decoder", new StringDecoder());
        socketChannel.pipeline().addLast("encoder", new StringEncoder());
        socketChannel.pipeline().addLast(new NettyClientHandler());
    }
}

package com.example.netty.client;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class NettyClientApplication {

    public static void main(String[] args) {
        SpringApplication.run(NettyClientApplication.class, args);
        //啟動netty客戶端
        NettyClient nettyClient = new NettyClient();
        nettyClient.start();
    }

}

收工！