udpserver.java

JAVA 2应用开发指南

import java.io.*;
import java.net.*;
import java.util.*;
public class UdpServer {
  public byte[] getTime() {
    Date d = new Date();
    return d.toString().getBytes();
  }
  public void go() throws IOException {
    DatagramSocket datagramSocket;
    DatagramPacket inDataPacket;
    DatagramPacket outDataPacket;
    InetAddress clientAddress;
    int clientPort;
    byte[] msg= new byte[100];
    byte[] time;
    datagramSocket = new DatagramSocket(8000);
    System.out.println("UDP server active on port 8000");
    while (true) {
      inDataPacket = new DatagramPacket(msg, msg.length);
      datagramSocket.receive (inDataPacket);
      clientAddress = inDataPacket.getAddress();
      clientPort = inDataPacket.getPort();
      time = getTime();
      outDataPacket = new  DatagramPacket(time, time.length,clientAddress, clientPort);
      datagramSocket.send(outDataPacket);
    }
  }
  public static void main (String args[]) {
    UdpServer udpServer = new UdpServer();
    try {
      udpServer.go();
    } 
    catch (IOException e) {
      System.out.println ("IOException occurred with socket.");
      System.out.println (e);
      System.exit(1);
    }
  }
}