Hi I've had some problems trying to get RMI working and was wondering if anyone can help me? I've tried implementing the client/server code two different ways - one way using a Registry object to bind my remote object and one using the Naming.rebind()/Naming.lookup() methods (my current code, which I'll supply in a sec).

I noticed when I was using the Registry object to bind the DriverObject I was getting errors about stuff not being serializable when trying to run the client. Is it talking about the objects that the DriverObject uses?

I'm running all of this on a windows machine using the following commands (the code is located in the folder C:\pid):

set CLASSPATH=
start rmiregistry

javac *.java
rmic -Djava.security.policy=policy.all javapid.DriverObject

java Server
java -Djava.security.policy=policy.all -classpath /pid ClientObject

When running the ClientObject I get the following error:

exporter: an exception occurred: access denied (java.net.SocketPermission 127.0.0.1:1099 connect,resolve)
java.security.AccessControlException: access denied (java.net.SocketPermission 127.0.0.1:1099 connect,resolve)
at java.security.AccessControlContext.checkPermission(Unknown Source)
at java.security.AccessController.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkPermission(Unknown Source)
at java.lang.SecurityManager.checkConnect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at sun.rmi.transport.proxy.RMIDirectSocketFactory.createSocket(Unknown Source)
at sun.rmi.transport.proxy.RMIMasterSocketFactory.createSocket(Unknown Source)
at sun.rmi.transport.tcp.TCPEndpoint.newSocket(Unknown Source)
at sun.rmi.transport.tcp.TCPChannel.createConnection(Unknown Source)
at sun.rmi.transport.tcp.TCPChannel.newConnection(Unknown Source)
at sun.rmi.server.UnicastRef.newCall(Unknown Source)
at sun.rmi.registry.RegistryImpl_Stub.lookup(Unknown Source)
at java.rmi.Naming.lookup(Unknown Source)
at ClientObject.main(ClientObject.java:405)

I've taken some of the code out of the driver object (the getters/setters are pretty much the same) for this post.

RemoteEvent.java
Code:
package javapid;
 
import java.rmi.Remote;
import java.rmi.RemoteException;
 
public interface RemoteEvent extends Remote
{
  public double getInput    ()          throws RemoteException;
  public double getOutput   ()          throws RemoteException;
  public double getKp       ()          throws RemoteException;
  public double getKi       ()          throws RemoteException;
  public double getKd       ()          throws RemoteException;
  public double getPlant    ()          throws RemoteException;
  public int    getSgm      ()          throws RemoteException;  
  public double getSgmiv    ()          throws RemoteException;
  public double getSgmav    ()          throws RemoteException;
  public double getSgni     ()          throws RemoteException;
  public void   setKp       (double Kp) throws RemoteException;
  public void   setKi       (double Ki) throws RemoteException;
  public void   setKd       (double Kd) throws RemoteException;
  public void   setPlant    (double g)  throws RemoteException;
  public void   setRate     (double r)  throws RemoteException;
  public void   setSgmiv    (double mi) throws RemoteException;
  public void   setSgmav    (double ma) throws RemoteException;
  public void   setSgni     (double ni) throws RemoteException;
  public void   setSgm      (int md)    throws RemoteException;
  public void   resetSigGen ()          throws RemoteException;
}
DriverObject.java
Code:
package javapid;
 
import java.rmi.*;
import java.rmi.server.*;
import java.rmi.registry.*;
 
public class DriverObject extends UnicastRemoteObject implements AsyncEvent, RemoteEvent {
 
  private int externalCount = 0;
  
  private SignalObject SO;
  private SystemObject SY;
  
  private int period = 20;
 
  public DriverObject() throws RemoteException {
    System.out.println("Creating remote control object");
    SO = new SignalObject(0.0,5.0,0.01,100,0,0.0);
    SY = new SystemObject(SO);
    this.Start();
  }  
  
  public DriverObject(SignalObject Sig, SystemObject Sys) throws RemoteException {
    System.out.println("Creating remote control object");
	  SO = Sig;
    SY = Sys;
    this.Start();
  }
  
  public double getInput() throws RemoteException {
    return SO.getOutput();
  }
      
  public void setKp(double Kp) throws RemoteException {
    SY.setKp(Kp);
  }
 
  public void Start() {
    ClockedEventObject SOT = new ClockedEventObject(period, SO);
    ClockedEventObject SOY = new ClockedEventObject(period, SY);
    ClockedEventObject DOT = new ClockedEventObject(period, this); 
    while(true) {}
  }
  
  public void handleAsyncEvent() {
// this is used by a clock object I created which is used in the Start() method.
// it implements the method defined in the AsyncEvent interface.
 
    externalCount++;
  }
 
  public static void main (String args[])
  {
      try
      {
          System.setSecurityManager(new RMISecurityManager());
        
          DriverObject Do = new DriverObject ();
 
          System.out.println ("Created remote object, now advertising it");
 
          //Registry registry = LocateRegistry.getRegistry ("localhost", 1099);
          //registry.rebind ("RemotePID", Do);
          Naming.rebind("RemotePID", Do);
 
          System.out.println ("Advertising completed");
      }
      catch (Exception e)
      {
          System.out.println ("exporter: an exception occurred: "+
                  e.getMessage ());
          e.printStackTrace ();
          System.exit (1);
      }
  }  
  
}
ClientObject.java
Code:
import javapid.*;
import java.rmi.*;
import java.rmi.registry.*;
 
class ClientObject
{
  
//  public void setRst(int i) {
//    try
//      {
//          System.out.println ("Starting client");
//
//          Registry registry = LocateRegistry.getRegistry ("localhost", 1099);
//          Object O          = registry.lookup("RemotePID");
//          RemoteEvent Rev   = (RemoteEvent) O;
//
//          if (i > 0) Rev.resetSigGen();
//      } catch (Exception e) {
//          System.out.println ("exporter: an exception occurred: "+
//                  e.getMessage ());
//          e.printStackTrace ();
//          System.exit (1);
//      }
//  }
  
  public static void main(String args[]) {
    System.setSecurityManager(new RMISecurityManager());
    
    try {
      System.out.println("Security Manager loaded");
      String url = "//localhost/RemotePID";
      
      RemoteEvent Rev = (RemoteEvent) Naming.lookup(url);
      System.out.println("Got remote object");
      
      System.out.println("Output is:"+ Rev.getOutput());
    } catch (Exception e) {
          System.out.println ("exporter: an exception occurred: "+
                  e.getMessage ());
          e.printStackTrace ();
          System.exit (1);
    }
  }
}
Thanks .