設計模式——適配器模式

8.

OO模式：適配器模式——將一個類的接口，轉換成客戶期望的另一個接口。適配器讓原本不兼容的類可以合作無間。

例子：用火雞去冒充鴨子

public interface Duck {
	public void quack();
	public void fly();
}

public interface Turkey {
	public void gobble();
	public void fly();
}

public class MallardDuck implements Duck {
	public void quack() {
		System.out.println("Quack");
	}
 
	public void fly() {
		System.out.println("I'm flying");
	}
}

public class WildTurkey implements Turkey {
	public void gobble() {
		System.out.println("Gobble gobble");
	}
 
	public void fly() {
		System.out.println("I'm flying a short distance");
	}
}

public class TurkeyAdapter implements Duck {
	Turkey turkey;
 
	public TurkeyAdapter(Turkey turkey) {
		this.turkey = turkey;
	}
    
	public void quack() {
		turkey.gobble();
	}
  
	public void fly() {
		for(int i=0; i < 5; i++) {
			turkey.fly();
		}
	}
}

public class DuckTestDrive {
	public static void main(String[] args) {
		MallardDuck duck = new MallardDuck();

		WildTurkey turkey = new WildTurkey();
		Duck turkeyAdapter = new TurkeyAdapter(turkey);

		System.out.println("The Turkey says...");
		turkey.gobble();
		turkey.fly();

		System.out.println("\nThe Duck says...");
		testDuck(duck);

		System.out.println("\nThe TurkeyAdapter says...");
		testDuck(turkeyAdapter);
	}

	static void testDuck(Duck duck) {
		duck.quack();
		duck.fly();
	}
}

public class DuckTestDrive {
	public static void main(String[] args) {
		MallardDuck duck = new MallardDuck();

		WildTurkey turkey = new WildTurkey();
		Duck turkeyAdapter = new TurkeyAdapter(turkey);

		System.out.println("The Turkey says...");
		turkey.gobble();
		turkey.fly();

		System.out.println("\nThe Duck says...");
		testDuck(duck);

		System.out.println("\nThe TurkeyAdapter says...");
		testDuck(turkeyAdapter);
	}

	static void testDuck(Duck duck) {
		duck.quack();
		duck.fly();
	}
}

以下是上述類的關係圖：

有沒有感覺和前面介紹的裝飾者模式很像？

我的理解：

裝飾者模式：用於拓展我們包裝的對象的行爲和責任，並不是“簡單傳送”就算了。

適配器模式：一定會進行接口的轉換。

提到適配者模式，就不得不提外觀模式，它將會在下一篇博客介紹。