Problem with registry.lookup()

[Kevin Cao]

Try to test on 2 boxes, right now is on single machine.
On server:

 registry.rebind("//localhost/Factory", factory); 

On client:

  this.connectionString = System.getProperty("suncertify.hostname");
if (this.connectionString == null){
this.connectionString = "localhost";
                }
                
                this.registry = LocateRegistry.getRegistry(1099);
this.connectionFactory = (Factory)registry.lookup("//" + connectionString + "/Factory");

I know my computer's name by using "ping localhost". And I ran this application using

 java -Dsuncertify.hostname = <my computer name> ApplicationStarter

It only works if I omit -D options, otherwise it won't. Any suggestions are very appreciated.
Kevin

[John Smith]

registry.rebind("//localhost/Factory", factory);

You need to understand that the first parameter to Registry.rebind() is not a URL. Instead, it is just a simple String that maps to your object in the registry. For example:

                // bind
registry.rebind("My Super Duper Flight Services", factory);                
// lookup
String service = "//" + serverDNS + ":" + serverPort + "/" + "My Super Duper Flight Services";
Factory factory = (Factory) Naming.lookup(service);

The confusion comes from the fact that Sun's java doc for Registry.rebind() was wrong up to 1.4.0.
Once you accept this fact, everything else will fall into place.
Eugene.
[ March 26, 2003: Message edited by: Eugene Kononov ]

[Kevin Cao]

Eugene,
Thanks so much for your response. I used to using Naming.rebind() and Naming.lookup(), which uses URL-formatted name. So if I want to test on 2 boxes, I have to use Naming instead of Registry. Otherwise the hostname will always be passed as String, and it is not bound that way.
The only way to use Registry is pass hostname whenever starts the server(binding), and pass the same hostname when starts client, so they will have the same "STRING" name. Do I understand it correctly.
Kevin

[John Smith]

So if I want to test on 2 boxes, I have to use Naming instead of Registry. Otherwise the hostname will always be passed as String, and it is not bound that way.

I am not sure what you mean. I also tested on two different machines, and it worked fine. The server binds to Registry, and the client looks up the remote object using Naming. No problem.

The only way to use Registry is pass hostname whenever starts the server(binding)

No, you don't need to pass hostname, -- the server already knows its hostname, and you don't need to specify it when binding an object to registry. Try it exactly as in the code that I posted above, -- it will work.
Eugene.

[Kevin Cao]

Eugene,
After your previous post. I checked javadoc, the java.rmi.Registry.rebind/lookup takes String, and java.rmi.Naming.rebind/lookup takes URL-formatted name, exactly like you said. So I changed to java.rmi.Naming and tested on 2 machines, it works fine.
Again, thanks for your help.
Kevin