Hello.java

package examples.hello;

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

public interface Hello extends Remote { 
    String sayHello() throws RemoteException; 
}

• All methods must throw RemoteException since remote calls can fail due to network problems.
• It must be declared public.
• The data type of the remote object must be of the interface type (i.e., Hello), not the implementation type (i.e., HelloImpl).