J++ RMI to 1.4 JDK.

Question

Hi,
I am running a client on J++ that makes RMI calls to a server running on 1.4JDK.
When i run the client I get the following error :
java.rmi.UnmarshalException: Error unmarshaling return header
java.rmi.UnmarshalException: Error unmarshaling return header
at sun/rmi/transport/StreamRemoteCall.executeCall (StreamRemoteCall.java:208)
at sun/rmi/server/UnicastRef.invoke (UnicastRef.java:99)
at sun/rmi/registry/RegistryImpl_Stub.lookup (RegistryImpl_Stub.java:94)
at java/rmi/Naming.lookup (Naming.java:60)
at Class1.getConnectPort (Class1.java:39)
at Class1.main (Class1.java:25)
This error occurs at random. i.e. several Naming.lookup are successful however i get to the point where one will fail.
I have set my policy file on the server to grant permissions to all.
Anyone got any bright ideas as to what could be causing this on 1.4 VM. This doesnt seem to occur if my server run on 1.3 JVM.
thanks a lot.
The code to reproduce is below :
//Interface
package rmitest;
import java.rmi.Remote;
import java.rmi.RemoteException;
public interface IMyServer extends Remote {
public int getNum(int num) throws RemoteException;
import java.rmi.server.*;
import java.rmi.*;
import java.rmi.registry.*;
import java.io.*;
import java.security.*;
import java.net.SocketPermission;
public class MyServerImpl extends UnicastRemoteObject implements IMyServer {
public MyServerImpl() throws RemoteException {
public int getNum(int num) throws RemoteException {
return num;
public static void main(String args[]) {
//System.setSecurityManager(new InsecurityManager());
if (System.getSecurityManager() == null) {
System.setSecurityManager ( new RMISecurityManager());
try {
// start the registry
LocateRegistry.createRegistry(Registry.REGISTRY_PORT);
MyServerImpl server = new MyServerImpl();
Naming.rebind("MyServer", server);
} catch (Exception e) {
System.out.println("Exception during test");
System.err.println(e.getMessage());
e.printStackTrace();
}//end try/catch
import java.rmi.*;
import java.rmi.registry.*;
import rmitest.IMyServer;
public class Class1 {
public Class1() {
public static void main(String[] args) {
Class1 rmiCall = new Class1();
int port = rmiCall.getConnectPort();
public static int getConnectPort() {
int port = -1;
try {
if(System.getSecurityManager() == null) {
System.setSecurityManager( new RMISecurityManager() );
for( int k = 0; k < 1500; k++){
IMyServer abc = (IMyServer) Naming.lookup("//ServerName/MyServer");
//Remote call.
System.out.println( abc.getNum(k) );
catch( Exception e ) {
System.out.println( e );
e.printStackTrace();
finally{
return port;
}

Answer 1

I'm having the same trouble... funny I work at the same company!!
If anyone knows how to get hold of the j++ source code.... please tell us!
(nice one charbell I was about to post a message here myself...
I like the last suggestion.... very usefull!)