import java.io.*;import java.net.*;import java.util.*;public class DatagramsClient {  public static void main(String[] args) throws IOException {    //創建DatagramSocket類,用于發送與接收數據包    DatagramSocket socket = new DatagramSocket();    //創建byte數組    byte[] buf = new byte[200];    //創建包括服務器地址的InetAddress類    InetAddress address = InetAddress.getByName("localhost");    //創建帶有網絡地址與端口的數據包    DatagramPacket packet = new DatagramPacket(buf, buf.length, address, 8888);    //根據網絡地址與端口發送數據包    socket.send(packet);    //創建一個數據包    packet = new DatagramPacket(buf, buf.length);    //接收返回的數據包    socket.receive(packet);    //通過getData()方法獲取數據包的數據    String received = new String(packet.getData());    System.out.println("數據包的數據: " + received);    socket.close();       //關閉UDP的scoket接口  }}