Strategy pattern

StrategyPattern.java

public abstract class Animal {
  SwimmingBehavior swimmingBehavior;
  SoundBehavior soundBehavior;
  
  public abstarct void display();
  
  public void performSwimming() {
    swimmingBehavior.swim();
  }
  
  public void performSound() {
    soundBehavior.sound();
  }
  
  // You can dynamically specify the behavior with the methods below.
  public void setSwimmingBehavior(SwimmingBehavior swb) {
    swimmingBehavior = swb
  }
  
  public void setSoundBehavior(SoundBehavior sb) {
    soundBehavior = sb
  }
  
  public void breathe() {
    System.out.println("All animals breathe.")
  }
}

public interface SwimmingBehavior {
  public void swim();
}

public class SwimmingWithFeet implements SwimmingBehavior{
  public void swim() {
    System.out.println("I can swim!");
  }
}

public class SwimmingNoWay implements SwimmingBehavior {
  public void swim() {
    System.out.println("I can't swim")
  }
}

public interface SoundBehavior {
  public void sound();
}

public class Barking implements SoundBehavior {
  public void sound() {
    System.out.println("Bow!")
  }
}

public class Howling implements SoundBehavior {
  public void sound() {
    System.out.println("Howl~~~")
  }
}

pulic class MuteSound implements SoundBehavior {
  public void sound() {
    System.out.println("Quiet...")
  }
}

public class Dog extends Animal {
  public Dong() {
    swimmingBehavior = new SwimmingWithFeet();
    soundBehavior = new Barking();
  }
  
  public void display() {
    System.out.println("I'm dog!")
  }
}

public class AnimalSimulator {
  public static void main(String[] args) {
    Animal dog = new Dog();
    dog.performSwimming();
    dog.performSound();
  }
}