Running 2 separate programs at once w/ RMI

Question

Hello Java forum. I am coding a stock market simulator with Java. I need the stock prices to be CONSTANTLY dynamic. So what I have is a driverClass that is the front for the market sim. It displays the stock prices and such, and therefor must grab variables from the engineClass which is constantly looping to randomly increase or decrease the stock values of 50 different stocks. Here is a VERY watered down version of these 2 classes:
driverClass (the front of the program)
public class driverClass
     public static void main (String[]args)
     int stockPrice = 0, numShares = 0, totalPrice = 0;
     /*Some way to take values from the constantly running engineClass
     stockPrice = code to get value from the Dell method in the engineClass
     numShares = Keyboard.readInt();
     totalPrice = numShares * stockPrice
     System.out.print ("The stock's price is " + stockPrice);
     System.out.print (". You have " + numShares + " shares of Dell stock.");
     System.out.println (" Your net worth is " + totalPrice + ".");
}The engineClass (constantly changes all of the stock prices)
public class engineClass
     public static void main (String[]args)
          //Does this have to be a main method (like a driver) or can it/does it have to be in the form of an object class?
          int repeat = 100, stockValue = 20;
          while(repeat > 0)
               Dell(stockValue);
               repeat--;
     public static int Dell (int stockPrice)
          return stockPrice;
     //does basically this for the other 49 stocks
}So what I need is to be able to call on a method in the engineClass FROM the driverClass while the engine is constantly changing all of the stock prices. Everyone has told me that RMI is the BEST way to do this, but RMI is extremely confusing to me. All the talk of servers and clients, while not retaining the same network meaning perhaps, still throws me off. Can someone please tell me the simplest way to use RMI to access a method in the engineClass from the driverClass with both of them running. Thanks!

Answer 1

One FINAL issue to clear up it seems:
Okay everything is going well, except it seems I have one final issue at hand. The method that I am remotely invoking is static, and I can't think of a way to make it so that it doesn't have to be. Look at my code:
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
Client:
public class Drive
    public static void main(String[] args)
          String host = (args.length < 1) ? null : args[0];
          try
              Registry registry = LocateRegistry.getRegistry(host);
              RemoteInterface stub = (RemoteInterface) registry.lookup("Hello");
              int response = stub.UnionPacific();
              System.out.println("response: " + response);
          catch (Exception e)
              System.err.println("Client exception: " + e.toString());
              e.printStackTrace();
    private Drive()
}Server:
import java.rmi.registry.Registry;
import java.rmi.registry.LocateRegistry;
import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;
public class Engine implements RemoteInterface
     public static int price, total1, total2, current = 1;
     public static boolean cont = true;
    public static void main(String[]args)
          try
               java.rmi.registry.LocateRegistry.createRegistry(1099);
               System.out.println("RMI registry ready.");
          catch (Exception e)
               System.out.println("Exception starting RMI registry:");
               e.printStackTrace();
          try
               Engine obj = new Engine();
              RemoteInterface stub = (RemoteInterface) UnicastRemoteObject.exportObject(obj, 0);
              // Bind the remote object's stub in the registry
              Registry registry = LocateRegistry.getRegistry();
              registry.bind("Hello", stub);
              System.err.println("Stock Market Ready");
          catch (Exception e)
              System.err.println("Server exception: " + e.toString());
              e.printStackTrace();
         while(cont)
               price++;
               if(current == 1)
                    //UnionPacific();
                    current = 2;
               else
                    //Altera();
                    current = 1;
     public Engine()
     public int UnionPacific()
          return total1;
     public int Altera()
          return total2;
}Remote Interface:
import java.rmi.Remote;
import java.rmi.RemoteException;
public interface RemoteInterface extends Remote
    int UnionPacific() throws RemoteException;
    int Altera() throws RemoteException;
}So you see how this works? The main method of the server is constantly updating the totals of both Altera() and UnionPacific(). These 2 need to be invoked remotely, but in order to call them from the static main loop, they also have to be static, but the remote interface does not allow this! It is very annoying. can anyone tell me how to get around this, or a way to make it so my altera and unionpacific methods dont have to be static? THANKS!!!
Edited by: NasaGuru on Mar 11, 2009 6:48 PM