Activatable RMI - can not get to work

Question

Hi
I am desperate to get activatable RMI to work. I tried the Sun tutorial example and even that I can not get to work.
I would really appreciate it if someone can highlight where my stupidity lies.
Here are my sources:
Remote Interface:
package compute;
public interface Compute extends java.rmi.Remote
void executeTask() throws java.rmi.RemoteException;
Client code:
package client;
import compute.*;
import java.rmi.*;
public class Client
public static void main(String[] args)
if (System.getSecurityManager()==null)
System.setSecurityManager(new RMISecurityManager());
try
Compute comp=(Compute) Naming.lookup("//"+args[0]+"/ComputeIT");
comp.executeTask();
System.out.println("returned");
catch (Exception e)
System.out.println("Exception caught!");
System.out.println(e.getMessage());
Server Implementation:
package actengine;
import compute.*;
import java.rmi.*;
import java.rmi.activation.*;
public class ActServerImp extends Activatable implements Compute
public ActServerImp(ActivationID id,
MarshalledObject mobj) throws RemoteException
super(id,0);
public void executeTask() throws RemoteException
return;
Server Setup program:
package actengine;
import compute.*;
import java.rmi.*;
import java.rmi.activation.*;
import java.util.Properties;
public class ActServerSetup
public static void main(String args[])
try
System.setSecurityManager(new RMISecurityManager());
Properties props=new Properties();
props.setProperty("java.security.policy",
"/u/pretora/java/rmi/actsrv/security.policy");
ActivationGroupDesc.CommandEnvironment ace = null;
ActivationGroupDesc agd=new ActivationGroupDesc(props,ace);
ActivationGroupID agi=ActivationGroup.getSystem().registerGroup(agd);
// ActivationGroup.createGroup(agi,agd,0);
String location="file:/u/pretora/java/rmi/actsrv/";
MarshalledObject data=null;
ActivationDesc ae=
new ActivationDesc(agi,"actengine.ActServerImp",location,data);
Compute cri=(Compute)Activatable.register(ae);
System.out.println("Remote reference obtained");
Naming.rebind("ComputeIT",cri);
System.out.println("Remote reference bound to registry");
// System.exit(0);
catch (Exception e)
System.out.println("ActServerSetup caught "+e);
e.printStackTrace(System.out);
If I run the lot (rmiregistry and rmid (with security pol!)) I get the following exception on the server side:
java.io.StreamCorruptedException: InputStream does not contain a serialized obje
.at java.io.ObjectInputStream.readStreamHeader(ObjectInputStream.java:855)
.at java.io.ObjectInputStream.<init>(ObjectInputStream.java:174)
.at sun.rmi.server.MarshalInputStream.<init>(MarshalInputStream.java:102)
.at sun.rmi.server.ActivationGroupInit.main(ActivationGroupInit.java:52)
the client side just times out:
failed to activate object; nested exception is:
java.rmi.activation.ActivationException: timeout creating child process
It does work if I uncomment the 2 commented lines in the server setup progam and let rmid use the setup program's JVM to instantiate the ActServerImp.
Any ideas much appreciated. Thanks

Answer 1

I finally found my problem. By changing the codebase string in ActServerSetup.java from file:/// to http:// URL, I was able to see in Apache HTTP server's log the 404 errors for my interface classes. The line that read
String location="file:/u/pretora/java/rmi/actsrv/";
had to be changed to
String location="file:///u/pretora/java/rmi/actsrv/ file:///u/pretora/java/rmi/common/";
Now I am all set.
thanks