Exploring Super Interfaces in Java 8.

gistfile1.java

/* INTERFACES */

interface Plane {

  default void drive() {
    System.out.println("We are driving a plane!");
  }

}

interface Boat extends Vehicle {

  @Override
  default void drive() {
    System.out.println("We are driving a boat!");
  }

}

interface Vehicle {

  default void drive() {
    System.out.println("Everything is driveable...");
  }

}

/* CLASSES */

class Seaplan implements Plane, Boat {

  @Override
  public void drive() {
    // System.out.println("Woo! Let's drive!");
    Plane.super.drive(); // #DiamondInheritance. Specify the chosen interface.
  }

}

class Bicycle implements Vehicle {

  // takes default drive() implementation provided in the interface.

}

class Main {

  public static void Main() {
    Seaplan s = new Seaplan();
    s.drive();

  }

}