daytimeserver1.java

JAVA分布式程序学习的课件（全英文）

import java.io.*;
import java.util.Date;   // for obtaining a timestamp

/**
 * This module contains the application logic of a Daytime server
 * which uses a connection datagram socket for interprocess communication.
 * A command-line argument is required to specify the server port.
 * @author M. L. Liu
 */
public class DaytimeServer1 {
   public static void main(String[] args) {
      int serverPort = 13;    // default port
      if (args.length == 1 )
         serverPort = Integer.parseInt(args[0]);       
      try {
         // instantiates a datagram socket for both sending
         // and receiving data
   	   MyServerDatagramSocket mySocket = new MyServerDatagramSocket(serverPort); 
         System.out.println("Daytime server ready.");  
         while (true) {  // forever loop
            DatagramMessage request = mySocket.receiveMessageAndSender();
            System.out.println("Request received");
            // The message received is unimportant; it is the sender's
            // address that we need in order to reply.
			   // Now obtain the timestamp from the local system.
            Date timestamp = new Date ();
            System.out.println("timestamp sent: "+ timestamp.toString());
            // Now send the reply to the requestor
            mySocket.sendMessage(request.getAddress( ),
                       request.getPort( ), timestamp.toString( ));
		   } //end while
       } // end try
	    catch (Exception ex) {
         System.out.println("There is a problem: " + ex);
	    } // end catch
   } //end main
} // end class