Java Strategy Design Pattern

See comments for three different types of behaviors:

public abstract class Duck {
  FlyBehavior flyBehavior;
  QuackBehavior quackBehavior;
  public Duck() {
  }
  public void setFlyBehavior (FlyBehavior fb) {
     flyBehavior = fb;
  }
  public void setQuackBehavior(QuackBehavior qb) {
     quackBehavior = qb;
  }
  /******************************************************
   * May vary from duck to duck.
   *****************************************************/
  public void performFly() {
     flyBehavior.fly();
  }
  public void performQuack() {
     quackBehavior.quack();
  }
  /******************************************************
   * Common to all ducks
   *****************************************************/
  public void swim() {
     System.out.println("All ducks float, even decoys!");
  }
  /******************************************************
   * Different for all ducks
   *****************************************************/
  abstract void display();
}

This is an implementation. See how it got three different types of behaviors.

/**
 * 1. Provide fly and quack behaviors
 * 2. Impliment display behavior
 * 3. Inherit swim behavior
 */
public class RubberDuck extends Duck {
 
   public RubberDuck() {
      flyBehavior = new FlyNoWay();
      quackBehavior = new Squeak();
   }
   public void display() {
      System.out.println("I'm a rubber duckie");
   }
}