Multiple interfaces : Interface « Class Definition « Java Tutorial

1. Java Tutorial
2. Class Definition
3. Interface

interface A {
  void aMethod();
}

interface B {
  void bMethod();
}

interface C {
  void cMethod();
}

class ClassA {
  public void aMethod() {
  }
}

class D extends ClassA implements A, B, C {
  public void bMethod() {
  }

  public void cMethod() {
  }
}

public class MainClass {
  public static void t(A x) {
    x.aMethod();
  }

  public static void u(B x) {
    x.bMethod();
  }

  public static void v(C x) {
    x.cMethod();
  }

  public static void w(ClassA x) {
    x.aMethod();
  }

  public static void main(String[] args) {
    D h = new D();
    t(h);
    u(h);
    v(h);
    w(h);
  }
}