如圖：我將接受到的packet傳過來后，在構造方法中能夠獲取對應的值（可以看到通過構造方法獲取到的port是55419），但是如果要在run方法中獲取端口號（第三個紅框標記部分）等信息，就獲取不到，程序變成阻塞中，沒有其他報錯信息~

我的代碼如下：

Server:

package?com.socket.socketsender.UDPSoceket;

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

public?class?UDPServer?{

????public?static?void?main(String[]?args)?throws?IOException?{
????????//接收請求
????????DatagramSocket?socket?=?new?DatagramSocket(8110);//指定服務器端口
????????byte[]?data?=?new?byte[1024];
????????DatagramPacket?packet?=?new?DatagramPacket(data,?data.length);//創建數據報，用于接收客戶端發送的數據
????????System.out.println("========服務器已啟動，正在等待客戶端發送數據======");
????????while?(true)?{
????????????socket.receive(packet);//此方法在接收到客戶端數據之前會一直阻塞
????????????new?Thread(new?ThreadUDPServer(socket,?packet)).start();
????????}
????}

????private?static?class?ThreadUDPServer?implements?Runnable?{
????????private?DatagramPacket?packet;
????????private?String?info;
????????private?DatagramSocket?socket;
????????private?InetAddress?address;
????????private?int?port;

????????public?ThreadUDPServer(DatagramSocket?socket,?DatagramPacket?packet)?{
????????????this.socket?=?socket;
????????????this.packet?=?packet;
????????????this.info?=?new?String(packet.getData(),?0,?packet.getLength());//在run方法中獲取不到info？？？
????????????this.address=packet.getAddress();
????????????this.port=packet.getPort();
????????}
????????@Override
????????public?void?run()?{
????????????int?test?=?packet.getPort();
????????????System.out.println("接收到客戶端的消息是："?+?info);
????????????//發送響應信息
????????????byte[]?data2?=?"這是服務器的響應信息：登錄成功".getBytes();
????????????DatagramPacket?packet2?=?new?DatagramPacket(data2,?data2.length,?address,?port);
????????????try?{
????????????????socket.send(packet2);
????????????}?catch?(IOException?e)?{
????????????????e.printStackTrace();
????????????}
????????}
????}
}

client:

package?com.socket.socketsender.UDPSoceket;

import?java.io.IOException;
import?java.net.*;

public?class?UDPClient?{

????public?static?void?main(String[]?args)?throws?IOException?{


????????try?(DatagramSocket?socket?=?new?DatagramSocket())?{
????????????//發送請求
????????????InetAddress?addresses?=?InetAddress.getByName("localhost");
????????????byte[]?data?=?"用戶名：小王；密碼：123456".getBytes();
????????????int?port?=?8110;
????????????DatagramPacket?packet?=?new?DatagramPacket(data,?data.length,?addresses,?port);
????????????byte[]?data2?=?new?byte[1024];
????????????socket.send(packet);
????????????//接收響應信息
????????????DatagramPacket?packet2?=?new?DatagramPacket(data2,?0,?data2.length);
????????????socket.receive(packet2);
????????????String?info?=?new?String(data2,0,packet2.getLength());
????????????System.out.println("接收到服務器的響應信息："+info);
????????}



????}
}