Thread: RMI Problems with doing calculations across a server/client platform

Hi, ive been working on this problem for about 5 hours now and haven't found a way to resolve it. It's an RMI program that has to be able to return the mean, mode and median of a set of numbers.

It's composed of 4 classes; a client, an implementation class (with the math), an Interface, and a server class.

Here's all of the code
Client

import java.rmi.NotBoundException;
import java.rmi.RMISecurityManager;
import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;
import java.io.*;
 
    public class rmiClient {
 
       public static void main (String[ ] args) throws RemoteException, NotBoundException {  
            if (System.getSecurityManager() == null) {
                System.setSecurityManager(new RMISecurityManager());
            }
 
       String hostName = "localhost"; // default host name
       // assign host machine name to connect to
       if (args.length != 0) {
          if (args[0] != null) hostName = args[0]; // user specified machine
       }  
 
        try {   
            // connect to the remote object via the registry    
            Registry registry = LocateRegistry.getRegistry(hostName);
            rmiInterface stub = (rmiInterface) registry.lookup("myFunctions");
 
            Scanner rmiScanner = new Scanner(System.in);
            System.out.println( '\n' + "Enter the numbers to be calculated" + '\n');
 
            int [] values = new int [8]; 
            int math;
            int number=0;
 
            int breaker;
            int i = 0;
 
            while (true && i<8) {
            	breaker = rmiScanner.nextInt();
            		if (breaker <=0)
            			break;
            			values[i]= breaker;
            					i++;
            }
            String tempArray = Arrays.toString(values);
 
 
 
            System.out.println();
            System.out.println("Enter your Selection: ");
            System.out.println("1 - Return the mean");
            System.out.println("2 - Return the mode");
            System.out.println("3 - Return the median");
            System.out.println("4 - Exit");
 
            math = rmiScanner.nextInt(); //read client request
 
            int results;
            results=0;
            if (math==1) {
 
					System.out.println("The mean is "+stub.mean(avg));
                	} 
 
        } catch (Exception e) {System.out.println("Error : " + e); }
        System.exit(0);
       }
 
 
 
    }

Implementation

import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
 
public class rmiImpl  implements rmiInterface { 
 
 
	int avg;
 
 
  // default constructor
  public rmiImpl() {
          super();
 } // end constructor 
 
  public int mean (int number){
   // calculates the mean of the numbers
	  int[] values = new int [8];
	  int i = 0;
	  for (i=0; i< values.length; i++)
	  {
		  avg = avg + values[i];
	  }
	  return avg / values.length;
 
  }
 
@Override
public int mode(int mode) throws RemoteException {
	// TODO Auto-generated method stub
	return 0;
}
 
@Override
public int median(int median) throws RemoteException {
	// TODO Auto-generated method stub
	return 0;
}
 
  /*public int mode (int mode){
	  int maxval = 0, maxCount = 0;
	  for (int i = 0; i < values.length; i++) {
		  int count = 0;
		  for (int j = 0; j < values.length; ++j) {
			  if (values[j] == values[i]) ++count;
		  }
		  if (count > maxCount) {
			  maxCount = count;
			  maxval = values[i];
		  }
	  }
	  return maxval;
  }
 
  public int median (int median) {
	  int mid = values.length/2;
	  if (values.length%2 == 1) {
		  return values[mid];
	  } else {
		  return (int) ((values[mid-1] + values[mid]) / 2.0);
	  }
	  }
	  */
  }

Interface

 
import java.rmi.Remote;
import java.rmi.RemoteException;
import java.rmi.registry.LocateRegistry;
 
 
public interface rmiInterface extends Remote {
 
	 public int mean(int number) throws RemoteException;
 
	 public int mode (int mode) throws RemoteException; 
 
	 public int median (int median) throws RemoteException;
 
}

Server class

import java.rmi.RMISecurityManager;
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
import java.rmi.server.UnicastRemoteObject;
 
	    public class Serverclass {
 
	        public static void main (String args[]) {
	            if (System.getSecurityManager() == null) {
	                System.setSecurityManager(new RMISecurityManager());
	            }       
 
	            try {
	                rmiImpl impl =  new rmiImpl();
	                rmiInterface rmiStub = (rmiInterface) UnicastRemoteObject.exportObject(impl, 0);
 
	                // Bind the remote object's stub in the registry
	                Registry registry = LocateRegistry.getRegistry();
	                registry.bind("myFunctions", rmiStub);
	            }
	            catch (Exception e) {System.out.println("Error: " + e); }
	            System.out.println("Server started waiting ...");
	        } // end main
 
	    } //  end CensorServer

If anyone could have a read over this i'd be hugely appreciative since i'm at a total loss at the moment.


I figure that I need to use this excerpt from rmiClient

if (math==1) {
 
					System.out.println("The mean is "+stub.mean(avg));
                	}

to display the results of the calculation performed in the implementation class..


Anyway hopefully someone can help,


thanks

bump