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最简单的网关转发程序

1. 监控端口2222，接收端口接到的数据
2. 将数据从第四位开始截取
3. 将数据转发到另外一台主机 本示例是 本机 192.168.35.1:3333
   盗用同事梁某版权，

使用技术： springboot netty

git hub 地址 ：

   
       
    
     4.0.0
        
    
     com.tiza.leo
        
    
     UdpGetwayForwardByNetty
        
    
     1.0-SNAPSHOT
        
            
                 
                      
       
        org.apache.maven.plugins
                       
       
        maven-compiler-plugin
                       
                           
        8                    
        
         8
                        
                   
                  
                      
       
        org.springframework.boot
                       
       
        spring-boot-maven-plugin
                       
                           
        
         com.tiza.leo.UdpGetwayForwardByNetty.Boot
                        
                       
                           
         
          
          
           repackage
           
          
                        
                   
              
         
        
            
                 
                      
       
        org.springframework.boot
                       
       
        spring-boot-dependencies
                       
       
        2.2.1.RELEASE
                       
       
        pom
                       
       
        import
                   
              
         
        
            
                 
      
       org.springframework.boot
                  
      
       spring-boot-starter-actuator
              
             
                 
      
       io.netty
                  
      
       netty-all
                  
      
       4.1.42.Final
              
             
                 
      
       org.projectlombok
                  
      
       lombok
                  
      
       1.18.12
              
             
                 
      
       org.apache.commons
                  
      
       commons-lang3
                  
      
       3.11
              
         
    
   

spring:  profiles:    active: devgateway:  inPort: 2222  outIp: 192.168.35.1  outPort: 3333

package com.tiza.leo.UdpGetwayForwardByNetty;import com.tiza.leo.UdpGetwayForwardByNetty.deamon.GatewayDeamon;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.boot.ApplicationArguments;import org.springframework.boot.ApplicationRunner;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;/** * @author leowei * @date 2021/3/30  - 23:00 */@SpringBootApplicationpublic class Boot implements ApplicationRunner {
       @Autowired    GatewayDeamon gatewayDeamon;    public static void main(String[] args) {
           SpringApplication.run(Boot.class,args);    }    //执行网关收回进程    @Override    public void run(ApplicationArguments args) throws Exception {
           gatewayDeamon.start();    }}

package com.tiza.leo.UdpGetwayForwardByNetty.handler;import io.netty.buffer.ByteBuf;import io.netty.channel.ChannelHandler;import io.netty.channel.ChannelHandlerContext;import io.netty.channel.ChannelInboundHandlerAdapter;import io.netty.channel.socket.DatagramPacket;import lombok.extern.slf4j.Slf4j;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.core.env.Environment;import org.springframework.stereotype.Component;import java.net.InetSocketAddress;/** * @author leowei * @date 2021/3/30  - 23:01 */@Slf4j@ChannelHandler.Sharable@Componentpublic class ReceiveHandler extends ChannelInboundHandlerAdapter {
       @Autowired    private Environment env;    /*    1. 从 channel  中取到msg  转换为buf 后 截取前9位扔掉    2. 将剩余的数据打包为一个DatagramPacket 发往 出口     */    @Override    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
           DatagramPacket datagramPacketIn =   (DatagramPacket) msg;        ByteBuf buf = datagramPacketIn.copy().content();        buf.skipBytes(3);        InetSocketAddress address = new InetSocketAddress(env.getProperty("gateway.outIp"), Integer.parseInt(env.getProperty("gateway.outPort")));        DatagramPacket datagramPacketOut = new DatagramPacket(buf, address);        ctx.channel().writeAndFlush(datagramPacketOut).sync();        datagramPacketIn.release();        //super.channelRead(ctx, msg);    }}

package com.tiza.leo.UdpGetwayForwardByNetty.deamon;import com.tiza.leo.UdpGetwayForwardByNetty.handler.ReceiveHandler;import io.netty.bootstrap.Bootstrap;import io.netty.channel.ChannelFuture;import io.netty.channel.ChannelInitializer;import io.netty.channel.ChannelOption;import io.netty.channel.ChannelPipeline;import io.netty.channel.nio.NioEventLoopGroup;import io.netty.channel.socket.nio.NioDatagramChannel;import lombok.extern.slf4j.Slf4j;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.boot.autoconfigure.couchbase.CouchbaseProperties;import org.springframework.core.env.Environment;import org.springframework.stereotype.Service;/** * @author leowei * @date 2021/3/30  - 23:02 */@Slf4j@Servicepublic class GatewayDeamon {
       @Autowired    private Environment env;    @Autowired    private ReceiveHandler receiveHandler;    public void start(){
           NioEventLoopGroup bossGroup = new NioEventLoopGroup();        NioEventLoopGroup workGroup = new NioEventLoopGroup();        Integer port = env.getRequiredProperty("gateway.inPort", Integer.class);        log.info("绑定udp端口{}",port);        try {
               Bootstrap bootstrap = new Bootstrap();            bootstrap.group(bossGroup)                    .channel(NioDatagramChannel.class)                    .option(ChannelOption.SO_BROADCAST, true)                    //设置了UDP socket读缓冲区为2M                    .option(ChannelOption.SO_RCVBUF, 1024 * 2048)                    .handler(new ChannelInitializer
   
    () {
                           @Override                        protected void initChannel(NioDatagramChannel channel) throws Exception {
                               ChannelPipeline pipeline = channel.pipeline();                            pipeline.addLast("receive", receiveHandler);                        }                    });            ChannelFuture future = null;            future = bootstrap.bind(port).sync();            future.channel().closeFuture().sync();        } catch (Exception e) {
               log.error(e.getMessage(),e);        }finally {
               bossGroup.shutdownGracefully();            workGroup.shutdownGracefully();        }    }}
   

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