18:58 [java_a] air> more OverLoad.java
public class OverLoad {
  static private Base[] arr = new Base[2];
  public static void main(String[] args) {
    arr[0] = new A();
    arr[1] = new B();
    Manager mgr = new Manager();
    for(int i=0; i < arr.length; i++) {
      mgr.test(arr[i]);
    }
    System.out.println("finished");
  }

  static class Manager {
    public void test(A arg) {
      System.out.println("A: "+arg);
    }
    public void test(B arg) {
      System.out.println("B: "+arg);
    }
    public void test(Base arg) {
      System.out.println("Base: "+arg);
    }
  }

  static interface Base {}
  static class A implements Base {}
  static class B implements Base {}
}
18:59 [java_a] air> java OverLoad
Base: OverLoad$A@33dff3a2
Base: OverLoad$B@33f42b49
finished
18:59 [java_a] air>