Override a default method using lambdas

Question

Given a simple interface with a default method:

private interface A {
    default void hello() {
        System.out.println("A");
    }
}

And a method that accepts an instance of it:

private static void print(A a) {
    a.hello();
}

I can override this using an anonymous class:

print(new A() {
    @Override
        public void hello() {
        System.out.println("OverHello");
    }
});

but if I try with a lambda print(() -> System.out.println("OverHello2"));, I get a compilation error.

No target method found

Is there a way to make the override with a lambda?

Answer 1

No, because your interface does not have exactly one unimplemented method (that a lambda could provide the implementation for).

See @FunctionalInterface.