What makes RMI different with socket programming? Write program using RMI technology to send two numbers to the server and the server returning the greatest number between them.

 RMI (Remote Method Invocation) is a higher-level technology compared to socket programming. While socket programming provides basic communication between processes, RMI allows the invocation of methods on remote objects as if they were local. This makes it easier to develop distributed systems in Java.

Here are some differences between RMI and socket programming:

1. Abstraction level: RMI provides a higher level of abstraction than socket programming. With RMI, you can invoke remote methods on remote objects, while with socket programming, you need to define and implement your own message protocol to send data between two systems.
2. Object-oriented: RMI is object-oriented, which means that you can pass objects between systems and invoke methods on those objects remotely. With socket programming, you need to serialize and deserialize data to send it between systems.
3. Transparency: RMI provides a high level of transparency, which means that the client doesn't need to know about the implementation details of the server. With socket programming, the client needs to know the IP address and port number of the server to establish a connection.
4. Ease of use: RMI provides a simpler programming model than socket programming. With RMI, you only need to define the remote interface, implement the server object, and register the server object with the RMI registry. With socket programming, you need to handle low-level details like creating sockets, opening streams, and parsing messages.

Overall, RMI is a more convenient and higher-level technology than socket programming for developing distributed applications in Java

Here's an example program using RMI technology to send two numbers to the server and the server returning the greatest number between them:

Server Implementation:

import java.rmi.RemoteException;
import java.rmi.server.UnicastRemoteObject;

public class GreaterNumberImpl extends UnicastRemoteObject implements GreaterNumber {
    protected GreaterNumberImpl() throws RemoteException {
        super();
    }
    public int findGreaterNumber(int num1, int num2) throws RemoteException {
        if(num1 > num2) {
            return num1;
        }
        else {
            return num2;
        }
    }
}

Client Implementation:

import java.rmi.registry.LocateRegistry;
import java.rmi.registry.Registry;
public class Client {
    public static void main(String[] args) {
        try {
            // get the registry
            Registry registry = LocateRegistry.getRegistry("localhost", 1099);
            // get the remote object
            GreaterNumber greaterNumber = (GreaterNumber) registry.lookup("GreaterNumber");
            // call the remote method
            int result = greaterNumber.findGreaterNumber(5, 10);
            System.out.println("Greater Number is: " + result);
        }
        catch (Exception e) {
            System.err.println("Client exception: " + e.toString());
            e.printStackTrace();
        }
    }
}

GreaterNumber Interface:

import java.rmi.Remote;
import java.rmi.RemoteException;

public interface GreaterNumber extends Remote {
    int findGreaterNumber(int num1, int num2) throws RemoteException;
}

In this example, we have created a GreaterNumber interface that extends the Remote interface to mark the methods that can be invoked remotely. Then, we have implemented the GreaterNumberImpl class that implements the GreaterNumber interface and overrides the findGreaterNumber method to return the greater number between two numbers.

The server registers this object with the RMI registry using Naming.rebind(). On the client side, we get a reference to the remote object using registry.lookup() and then call the remote method findGreaterNumber() to get the greatest number between two numbers.

This program uses RMI technology to communicate between the server and the client, making it easier to develop distributed applications.