SpringBoot中使用UDP监听端口获取数据

需求：在springboot项目启动后，另开启一个线程来监听某个端口发送的udp包数据，并且实时将获取到的数据入库。

因为udp没有response，所以先确定用工具能接收到udp包数据，创建udp server来监听某个端口，创建udp client给指定ip和端口发数据包，联调时候先用此工具看看能否接收到外部发送到本地的udp数据包。

package com.genew.nms.utils.WebSocket;

import com.genew.nms.bean.BulkCallRecord;
import com.genew.nms.service.bulkcalltask.IBulkCallRecordService;
import com.genew.nms.utils.ApplicationContextUtil;
import lombok.extern.slf4j.Slf4j;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.*;
import java.time.LocalDateTime;
import java.time.ZoneOffset;




@Slf4j
@WebListener
public class UdpClient implements ServletContextListener {


    public static final int MAX_UDP_DATA_SIZE = 4096;
    public static final int UDP_PORT = 9072;
    public static DatagramPacket packet = null;
    public static DatagramSocket socket = null;

    @Override
    public void contextInitialized(ServletContextEvent sce) {
        try {
            log.info("Start thread to listen to UDP(port:{}) data!" , UDP_PORT );
            // 启动一个线程，监听UDP数据报
            new Thread(new UDPProcess(UDP_PORT)).start();
        } catch (Exception e) {
            e.printStackTrace();
        }

    }

    class UDPProcess implements Runnable {
        public UDPProcess(final int port) throws SocketException {
            //创建服务器端DatagramSocket，指定端口
            socket = new DatagramSocket(port);
        }

        @Override
        public void run() {
            while (true) {
                byte[] buffer = new byte[MAX_UDP_DATA_SIZE];
                packet = new DatagramPacket(buffer, buffer.length);
                try {
                    log.info("waiting udp data!");
                    socket.receive(packet);
                    new Thread(new Process(packet)).start();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

        }
    }

    class Process implements Runnable {
        public Process(DatagramPacket packet) throws UnsupportedEncodingException {
            // 接收到的UDP信息，然后解码
            byte[] buffer = packet.getData();
            String data = new String(buffer, "UTF-8").trim();
            log.info("UDP Received Data:{}", data);
        }

        @Override
        public void run() {
            try {
                log.info("Start UDP Response.");
                //1.定义客户端的地址、端口号、数据
                InetAddress address = packet.getAddress();
                int port = packet.getPort();
                byte[] data2 = "{'request':'alive','errcode':'0'}".getBytes();
                //2.创建数据报，包含响应的数据信息
                DatagramPacket packet2 = new DatagramPacket(data2, data2.length, address, port);
                //3.响应客户端
                socket.send(packet2);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

    }

    @Override
    public void contextDestroyed(ServletContextEvent sce) {
        log.info("UDPListener destroyed！");
    }

   

}

为什么写这一层，是因为在实际开发中可能需要注入某一个service来将数据入库，但新建线程中是无法直接使用autowired来注入service的，所以后续的操作是来解决这方面的问题的。如果没有此需要，可以直接跳过。

直接复制下面代码到项目。

package com.genew.nms.utils;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.stereotype.Component;


@Component
public class ApplicationContextUtil implements ApplicationContextAware {

    private static ApplicationContext applicationContext = null;

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        ApplicationContextUtil.applicationContext = applicationContext;
    }

    public static Object getBeanByName(String beanName) {
        if (applicationContext == null) {
            return null;
        }
        return applicationContext.getBean(beanName);
    }

    public static  T getBean(Class type) {
        return applicationContext.getBean(type);
    }
}

 然后在类中取消使用autowired来注入sevice，使用下面的方式来获取service对象。

IBulkCallRecordService recordService = ApplicationContextUtil.getBean(IBulkCallRecordService.class);