instancing subinterface problem

[almoes]

Hi all!

If I have an interface1 which extends interface2, and then I have a method which provides me with an event which delivers me interface2, how can I retrieve an instance to interface1? I hope its not too confusing :-S thanxs

cheers,
alej

 

[LordOfCode]

Well, actually any interface2 object reference can be assigned to an interface1 object reference, because interface2 extends interface1.

Now, Why do you want to cast interface2 to interface1 if interface2 can do everything interface1 does and even more?

Anyway, here's an example

//First interface
interface Interface1{
    public void sayYes();
}

//Second interface extends first interface
interface Interface2 extends Interface1{
    public void sayNo();
}

//This class implements interface2 and because it extends from interface1 also implements this one
class Implementation implements Interface2{
    public void sayNo() {
        System.out.println("No");
    }

    public void sayYes() {
        System.out.println("Yes");
    }

}

/*This class simulates your event, returning an Interface2 instance*/
class EventSimulator{
    public Interface2 getInterface2(){
        return new Implementation();
    }
}

public class Application {

    public static void main(String[] args) {
        EventSimulator event = new EventSimulator();
        //I assign an interface2 to an interface1 object
        Interface1 result = event.getInterface2();
        result.sayYes();
    }
   
}

edalorzo@hotmail.com

 

[almoes]

Hey really cool, i think i was really blind this time!
thanxs,
alej

 

[almoes]

Hi,

I am having some problems here again....
these are my definitions.

Interface Connection
Interface EspecialConnection extends Connection.

I get compilation error if I try:

Connection normalConn= new Connection();
EspecialConnection varConn=normalConn;

any ideas?
thanxs,
alej

 

[almoes]

Sorry, i think i got it:

EspecialConnection varConn=(EspecialConnection)normalConn;