How to find the first declaring method for a reference method
- by Oliver Gierke
Suppose you have a generic interface and an implementation:
public interface MyInterface<T> {
void foo(T param);
}
public class MyImplementation<T> implements MyInterface<T> {
void foo(T param) {
}
}
These two types are frework types. In the next step I want allow users to extend that interface as well as redeclare foo(T param) to maybe equip it with further annotations.
public interface MyExtendedInterface extends MyInterface<Bar> {
@Override
void foo(Bar param);
// Further declared methods
}
I create an AOP proxy for the extended interface and intercept especially the calls to furtherly declared methods. As foo(…) is no redeclared in MyExtendedInterface I cannot execute it by simply invoking MethodInvocation.proceed() as the instance of MyImplementation only implements MyInterface.foo(…) and not MyExtendedInterface.foo(…).
So is there a way to get access to the method that declared a method initially? Regarding this example is there a way to find out that foo(Bar param) was declared in MyInterface originally and get access to the accoriding Method instance?
I already tried to scan base class methods to match by name and parameter types but that doesn't work out as generics pop in and MyImplementation.getMethod("foo", Bar.class) obviously throws a NoSuchMethodException. I already know that MyExtendedInterface types MyInterface to Bar. So If I could create some kind of "typed view" on MyImplementation my math algorithm could work out actually.
