interface « subclass « Java Class Q&A

1. How do you find all subclasses of a given class in Java?    stackoverflow.com

How does one go about and try to find all subclasses of a given class (or all implementors of a given interface) in Java? As of now, I have a method to ...

2. Java: Prevent subclass from providing a different interface than base class    stackoverflow.com

Is there a means to prevent a subclass from exposing public methods other than those defined in the base class, at compile-time? For example:

abstract public class AClass {

   abstract public ...

3. Java - For a given function foo(X i); in Interface X, why can't implementing class Y change it to foo(Y i)?    stackoverflow.com

For example

public interface X{
    public void foo(X i);
}

public class Y implements X{//error: doesn't implement foo(X i)...
    public void foo(Y i){
      ...

4. java:how to define capabilities of a subclass instance that can be derived from the superclass    stackoverflow.com

To make my question more concrete, let me pose it as a problem: situation description: We have 3 abstract concepts:

Boss:  which has a number of employees
Worker:  that can execute some types ...

5. Passing subclass in the interface method    coderanch.com

I have an interface that has a method like this public void method1(Object1 argObj1, Object2 argObj2) In the class that implemtns this method can i have public void method1(Object1 argObj1, SubClassObject2 obj2) where SubClassObj2 is the subclass of Object2? I thought this is possible, but it gives me an error during compilation.

6. Subclassing interfaces    coderanch.com

Let say I have two interfaces A and B. They have all but a couple of methods in common. I create a new interface C, and both A and B extends C. We know have the change to implement A, B but also C. And that really doesn't make sense (C is an incomplete contract, not very nice to implement it!) ...

7. Interface implementation in a subclass    coderanch.com

Hola, Class a is a superclass of class b. Class a also implements interface Implementable. Is subclass b required to provide implementation of Implementable although b itself did not explicitly declared that it implements Implementable? [code] public class a implements Implementable { ...//some code here for implementation of Implementable's methods } class b extends a { //does b have to provide ...

8. How find all subclasses and/or implementing classes of interface?    coderanch.com

Is there a way to list all classes available in the class path? If so, you can use reflection to check for each of the classes if they implement a given interface / extend a given (super) class. However, I'm not exactly sure if there is a way of listing all classes in the class path - afraid there isn't. But ...

9. Interfaces and subclasses    forums.oracle.com

The type B does not have a method called print. You're referring to the instance of A through a B reference, so you only have the methods defined by B and the methods it's inherited. By the way, I know you think using names like B, A and I will simplify things for us, but it won't, it's easier to think ...

10. Dynamic selection of Interface subclasses    forums.oracle.com

Hi, wonder if anyone can help. I'm writing a package that provides various tree-related GUI features. I've defined an interface (TreeLayout) which specifies a single static method (layout) that specifies coordinates for the nodes in a tree structure. There are various standard implementations of this interface within the package (eg table layout, tree layout, radial layout etc), but I want other ...

11. can subclass use a method in supercalss as the implementation of interface?    forums.oracle.com

It depends. If m is public then it is already inherited so you don't have to unless you want a overriding implementation. If m is private, it is not, so you have to. If it is protected, the Super Class method cannot hide the public method in the interface, so again, you have to. HTH. -o12

12. How to deal with subclasses that implement different interfaces    forums.oracle.com

Consider the above scenario. We have a BusRoute and TrainRoute object and both extend the abstract class Route which contains general methods needed by all subclasses. Route implements IRoute. This is straightforward. Notice TrainRoute implements the CountdownRoute interface but BusRoute does not. This is because TrainRoute is capable of starting a countdown operation and the BusRoute is not. CountdownRoute implements the ...