Write client-server classes to calculate the sum of 1 + 2 + 3 + ...+ nwith rmi APIs for one client and one server. The calculation of sum must be written in a remote method in the server programs. The remote method should return the value of: sum to the client.
The client calls the remote method of servers to receive the sum. The client displays the sum on its console. Please copy/paste your java classes and interface under the word:

Below are the programs' skeleton and a sample dialog:

The client class and interface:

import java.rmi.Remote;

//This interface is complete. Do not change it.

publicinterface Project3ServerInterface extends Remote {
publicint calculateSum(int n ) throws java.rmi.RemoteException;
}
import java.rmi.*;
import java.util.*;
public class Project3Client{
//Complete this class.
}
The server classes and interface:
import java.rmi.Remote;
//This interface is complete. Do not change it.
publicinterface Project3ServerInterface extends Remote {
publicint calculateSum(int n ) throws java.rmi.RemoteException;
}
import java.rmi.*;
import java.rmi.server.*;
publicclassCalculateSumServerImplextends UnicastRemoteObject implements Project3ServerInterface {
//Complete this class.
}
import java.rmi.*;
importjava.rmi.server.*;
import java.rmi.registry.Registry;
import java.rmi.registry.LocateRegistry;
importjava.net.*;
publicclass Project3Server{
//Complete this class.
}
A sample dialog:

Display output on the server side:

RMI registry cannot be located at port 16790
RMI registry created at port 16790
Hello Server ready.

Display output on the client side:

Enter a positive integer: 5
Lookup completed
The sum is: 15
Note: The green: 5 is what the user entered.
Note: This is just a sample. Your project should work for any positive integer for n.