UDP监听工具:

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;

public class UdpReceive {
    private boolean isRunning = false;
    private DatagramSocket socket;


    public UdpReceive(String ip, int port, onReceive onReceive) {
        try {
            if (isRunning) return;
            socket = new DatagramSocket(null);
            socket.setReuseAddress(true);
            socket.bind(new InetSocketAddress(ip, port));
            byte[] buffer = new byte[1024];
            DatagramPacket packet;
            isRunning = true;
            while (isRunning) {
                while (isRunning) {
                    packet = new DatagramPacket(buffer, buffer.length);
                    socket.receive(packet);
                    onReceive.receive(new String(packet.getData(), 0, packet.getLength()));
                }
            }
            close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void close() {
        isRunning = false;
        if (socket != null) {
            socket.close();
            socket = null;
        }
    }

    public interface onReceive {
        void receive(String msg);
    }
}

UDP发送工具:

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;

public class UdpSend {
    public static void sendSocket(String ip, int port, String msg) {
        try {
            DatagramSocket socket = new DatagramSocket();
            DatagramPacket packetSend = new DatagramPacket(msg.getBytes(), msg.getBytes().length, InetAddress.getByName(ip), port);
            socket.send(packetSend);
            socket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}