Because Java is a kingdom of nouns, and for the most part (method handles, which are just fancy reflection objects, aside), you can't name a function without cr

Because Java is a kingdom of nouns, and for the most part (method handles, which are just fancy reflection objects, aside), you can't name a function without creating a closure. Anonymous callback: Foo.foo(() -> bar()); Named callback: private final class MyFooDelegate implements FooDelegate { @Override public void doFoo() { bar(); } } ... Foo.foo(new MyFooDelegate())