OnJava8-Examples/typeinfo/AnonymousImplementation.java

// typeinfo/AnonymousImplementation.java
// Anonymous inner classes can't hide from reflection.
import typeinfo.interfacea.*;

class AnonymousA {
  public static A makeA() {
    return new A() {
      public void f() { System.out.println("public C.f()"); }
      public void g() { System.out.println("public C.g()"); }
      void u() { System.out.println("package C.u()"); }
      protected void v() { System.out.println("protected C.v()"); }
      private void w() { System.out.println("private C.w()"); }
    };
  }
}

public class AnonymousImplementation {
  public static void main(String[] args) throws Exception {
    A a = AnonymousA.makeA();
    a.f();
    System.out.println(a.getClass().getName());
    // Reflection still gets into the anonymous class:
    HiddenImplementation.callHiddenMethod(a, "g");
    HiddenImplementation.callHiddenMethod(a, "u");
    HiddenImplementation.callHiddenMethod(a, "v");
    HiddenImplementation.callHiddenMethod(a, "w");
  }
}
/* Output:
public C.f()
AnonymousA$1
public C.g()
package C.u()
protected C.v()
private C.w()
*/