两个具有相同方法名称的接口，当我覆盖时会发生什么？

Question

So I have a class 'MyClass' & two interfaces 'A' & 'B'

public class MyClass implements A, B {

    @Override
    public void mymethod(){
        System.out.println("hello world");
    }

}

...

public interface A {
    void mymethod();
}

...

public interface B {
    void mymethod();
}

What method from what interface here is being overridden?

I'm thinking both are?

Thanks (student)

Answer 1

In this case it will be like there is only one method. It will override "both" methods in this case because they have the exact same signatures. If the methods had different signatures (return type or something) then there would be a problem. Check out this answer here

For Example:

public class MyClass implements A, B {

    @Override
    public void mymethod(){
        System.out.println("hello world");
    }

}
...

public interface A {
    void mymethod();
}
...

public interface B {
    String mymethod();
}

This would cause a problem...

Answer 2

这既是因为它符合两个接口。

Answer 3

((A)(new MyClass())).mymethod();
((B)(new MyClass())).mymethod();

outputs

hello world
hello world

It's straightforward to test what can happen.

If you encounter this then there's potentially some common feature between A and B that could be abstracted to another interface that A and B both extend, or there's undesirable shared terminology between them causing the overlap and something might need renamed.

Answer 4

An interface is just a contract.

Implementing A means MyClass should have a method void mymethod() .

Implementing B means MyClass should have a method void mymethod() .

It's overriding "both", but I am not sure this is a proper way to say it.

It's just about filling a contract and making sure MyClass has the proper method.