timeclient.java

让初学者了解javaUDP的编程及应用

import java.io.*;
import java.net.*;
import java.util.*;

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

        if (args.length != 1) {
             System.out.println("Usage: java TimeClient <hostname>");
             return;
        }

            // get a datagram socket
        DatagramSocket socket = new DatagramSocket();

            // send request
        byte[] buf = new byte[128];
        InetAddress address = InetAddress.getByName(args[0]);
        DatagramPacket packet = new DatagramPacket(buf, buf.length, address, 5555);
        socket.send(packet);
    
            // get response
        packet = new DatagramPacket(buf, buf.length);
        socket.receive(packet);

	    // display response
        String received = new String(packet.getData());
        System.out.println("Nettime is: " + received.trim());
    
        socket.close();
    }
}