Android 设计模式：（一）观察者模式 —— 封装行为的大局观

package com.saltamontes.strategy; import com.saltamontes.strategy.fly.FlyBehavior; import com.saltamontes.strategy.quack.QuackBehavior; public abstract class Duck { protected FlyBehavior mFlyBehavior; protected QuackBehavior mQuackBehavior; public abstract void display(); public void performFly() { mFlyBehavior.fly(); } public void performQuack() { mQuackBehavior.quack(); } public void swim() { System.out.println("All ducks float, even decoys!"); } public void setFlyBehavior(FlyBehavior flyBehavior) { this.mFlyBehavior = flyBehavior; } public void setQuackBehavior(QuackBehavior quackBehavior) { this.mQuackBehavior = quackBehavior; } }