// patterns/abstractfactory/GameEnvironment.java
// (c)2017 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
// An example of the Abstract Factory pattern
// {java patterns.abstractfactory.GameEnvironment}
package patterns.abstractfactory;
import java.util.function.*;

interface Obstacle {
 void action();
}

interface Player {
 void interactWith(Obstacle o);
}

class Kitty implements Player {
 @Override
 public void interactWith(Obstacle ob) {
 System.out.print("Kitty has encountered a ");
 ob.action();
 }
}

class KungFuGuy implements Player {
 @Override
 public void interactWith(Obstacle ob) {
 System.out.print("KungFuGuy now battles a ");
 ob.action();
 }
}

class Puzzle implements Obstacle {
 @Override
 public void action() {
 System.out.println("Puzzle");
 }
}

class NastyWeapon implements Obstacle {
 @Override
 public void action() {
 System.out.println("NastyWeapon");
 }
}

// The Abstract Factory:
class GameElementFactory {
 Supplier<Player> player;
 Supplier<Obstacle> obstacle;
}

// Concrete factories:
class KittiesAndPuzzles
extends GameElementFactory {
 KittiesAndPuzzles() {
 player = Kitty::new;
 obstacle = Puzzle::new;
 }
}

class KillAndDismember
extends GameElementFactory {
 KillAndDismember() {
 player = KungFuGuy::new;
 obstacle = NastyWeapon::new;
 }
}

public class GameEnvironment {
 private Player p;
 private Obstacle ob;
 public
 GameEnvironment(GameElementFactory factory) {
 p = factory.player.get();
 ob = factory.obstacle.get();
 }
 public void play() {
 p.interactWith(ob);
 }
 public static void main(String[] args) {
 GameElementFactory
 kp = new KittiesAndPuzzles(),
 kd = new KillAndDismember();
 GameEnvironment
 g1 = new GameEnvironment(kp),
 g2 = new GameEnvironment(kd);
 g1.play();
 g2.play();
 }
}
/* Output:
Kitty has encountered a Puzzle
KungFuGuy now battles a NastyWeapon
*/