Problem with executing RMI Client Adder

[Zulfi Khan]

I got a following rmi code from internet. Server is compiled and running but client is giving error in execution (java.rmi.NotBoundException: Adder).

The interface code is:

    
import java.rmi.*;
public interface AddServerInterface extends Remote
{
public int sum(int a,int b) throws RemoteException;
}

==
And the code of class implementing the interface(Adder.java) is given below:

  
import java.rmi.*;
import java.rmi.server.*;
public class Adder extends UnicastRemoteObject implements AddServerInterface
{
Adder()throws RemoteException{

}
public int sum(int a,int b)throws RemoteException
{
return a+b; 
}
}

==
And the code for AddServer.java is:

   
import java.rmi.*;
import java.rmi.registry.*;
public class AddServer{
public static void main(String args[]){
if(System.getSecurityManager() == null)
         System.setSecurityManager(new SecurityManager());
     
try{
AddServerInterface addService=new Adder();
Naming.rebind("AddService",addService);	
//addService object is hosted with name AddService. 

}catch(Exception e){System.out.println(e);}
}
}

==
The code for Client  (Client. Java)is:

  
import java.rmi.*;
public class Client{
public static void main(String args[]){
try{
AddServerInterface st=(AddServerInterface)Naming.lookup("//localhost/Adder");
System.out.println(st.sum(25,8));
}catch(Exception e){System.out.println(e);}
}
}

==
The code for policy file is:

 
grant{
permission java.security.AllPermission;
};

List of all files:

       
Directory of rmi Add

10/03/2017  10:41 PM    <DIR>          .
10/03/2017  10:41 PM    <DIR>          ..
10/04/2017  06:45 AM               352 Adder.class
10/03/2017  11:08 PM               237 Adder.java
10/04/2017  06:45 AM               797 AddServer.class
10/03/2017  10:57 PM               420 AddServer.java
10/04/2017  06:45 AM               215 AddServerInterface.class
10/03/2017  10:48 PM               129 AddServerInterface.java
10/04/2017  06:45 AM               669 Client.class
10/03/2017  10:55 PM               252 Client.java
06/14/2017  08:21 PM                51 policy
               9 File(s)          3,122 bytes
               2 Dir(s)  565,344,907,264 bytes free

>

Compilation:
I am able to compile all these files:

    
>javac *.java


>

No problem with starting registry and server

     
>rmiregistry &
> java -Djava.security.policy=policy AddServer
 

However when I am executing Client.java, I am getting following error:

    
>java Client
[b]java.rmi.NotBoundException: Adder
[/b]
>

Some body please guide me.

Zulfi.

[Paul Clapham]

It's been an extremely long time since I had to set up an RMI connection by hand. However you have these two lines of code:

Naming.rebind("AddService",addService); 

AddServerInterface st=(AddServerInterface)Naming.lookup("//localhost/Adder");

My guess is that they are designed to configure the connection between the client and the server? If that's the case then shouldn't they use the same name?

[Paul Clapham]

By the way RMI isn't a beginning Java topic so I moved your post out of the Beginning Java forum. (If you're really a beginner you might want to reconsider the idea of studying RMI until you get more experience.)

[Zulfi Khan]

Hi Paul Clapham,
you are right. Client should search the registry using "AddService" string. I changed my client code and now its running.

import java.rmi.*;
public class Client{
public static void main(String args[]){
try{
AddServerInterface st=(AddServerInterface)Naming.lookup("//localhost/AddService");
System.out.println(st.sum(25,8));
}catch(Exception e){System.out.println(e);}
}
}

Next time i would follow your advice regarding use of appropriate forum. I have a feeling that begginer's forum get more response. Can we post on multiple forums??

Zulfi.

[Zulfi Khan]

Hi,
i forgot to show the output:

>java Client
33

>

Thanks. God bless you.

Zulfi.