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

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

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

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 :).