counterclienthelper1.java

JAVA分布式程序学习的课件（全英文）

import java.net.*;

/**
 * This class is a module which provides the application logic
 * for a Counter Client.
 * @author M. L. Liu
 */

public class CounterClientHelper1 {
	
   public static int getCounter(String hostName,
      String portNum){   
  
      int counter = 0; 
      String message = "";
      try {      
  		    InetAddress serverHost = 
             InetAddress.getByName(hostName);
  		    int serverPort = Integer.parseInt(portNum);
          // instantiates a datagram socket for both sending
          // and receiving data
   	    MyDatagramSocket mySocket = new MyDatagramSocket();  
          mySocket.sendMessage( serverHost, serverPort, "");
			 // now receive the timestamp
          message = mySocket.receiveMessage();
/**/      System.out.println("Message received: " + message);
          counter = Integer.parseInt(message.trim());
		    mySocket.close( );
       } // end try
	    catch (Exception ex) {
          ex.printStackTrace( );
	    } // end catch
       return counter;
   } //end main 
} //end class