使用 CMD 的 java RMI 的端口已在使用中的异常

Question

while Running RMI using java and CMD. java.rmi.server.ExportException is displayed. The Exception is that, port is already in use.

The server interface

import java.rmi.*;

public interface AdditionInterface extends Remote {
    public int add(int a, int b) throws RemoteException;
}

The Interface implementation

import java.rmi.Naming; 
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;

public class AdditionClient {
    public static void main(String[] args) {
        try {
            String host="";
            Registry registry = LocateRegistry.getRegistry(host);
            AdditionInterface hello = (AdditionInterface) registry.lookup("Addition");
            int result = hello.add(9, 2);
            System.out.println("Result is: " + result);

        } catch (Exception ex) {
            System.out.println("HelloClient Exception" + ex);
        }
    }
}

The Server Registry class

package chapter40;

import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;

public class AdditionServer {

    public static void main(String[] args) {

        try {
            Registry registry = LocateRegistry.getRegistry();
            AdditionInterface obj = new Addition();
            registry.rebind("Addition", obj);

            System.out.println("Addition Server is ready");
        } catch (Exception ex) {
            System.out.println("Addition Server failed" + ex);
        }

    }

}

The client program

import java.rmi.Naming; 
import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;

public class AdditionClient {
    public static void main(String[] args) {
        try {
            String host="";
            Registry registry = LocateRegistry.getRegistry(host);
            AdditionInterface hello = (AdditionInterface) registry.lookup("Addition");
            int result = hello.add(9, 2);
            System.out.println("Result is: " + result);

        } catch (Exception ex) {
            System.out.println("HelloClient Exception" + ex);
        }
    }
}

I separated the server from the client classes in two different projects for clarity sake

Answer 1

I searched through various threads and finally got this to work in a way different from [ but also a combination from what I'd seen ]

RUN THE SERVER PROGRAM THUS (from the command prompt):

1. change the directory to the source folder for the server cd c:\Users\Heavenly\workspace\RMIServerSide\src

2. compile the classes javac chapter40/*.java

3. start the RMI registry start rmiregistry

4. start the registry server class containing the main() method. NOTE THE LINE OF CODE IS SLIGHTLY DIFFERENT

start java -cp. chapter40.AdditionServer start java -cp. chapter40.AdditionServer (the server is now set)

RUN THE CLIENT PROGRAM

1. Change the directory to the source folder cd c:\Users\Heavenly\workspace\RMIClientSide\src

2. compile all the classes javac chapter40/*.java

3.Run the client program java chapter40.AdditionClient (everything is running now)