设计模式之工厂方法模式

主要内容:

1.工厂方法模式

2.多个工厂方法模式

3.静态方法模式

一.工厂方法模式

public abstract class Animal {public abstract void eat();}

public class Cat extends Animal {@Overridepublic void eat() {}}

<pre name="code" class="java">public class Dog extends Animal {@Overridepublic void eat() {}}

<pre name="code" class="java">package factory;public class AnimalFactory1 {public Animal createAnimal(String animal) {if ("dog".equals(animal)) {return new Dog();}if ("cat".equals(animal)) {return new Cat();}return null;}}

二.多个工厂方法模式

public class AnimalFactory2 {public Animal createDog() {return new Dog();}public Animal createCat() {return new Cat();}}

三.静态方法模式

public class AnimalFactory3 {public static Animal createDog() {return new Dog();}public static Animal createCat() {return new Cat();}}

四.测试

@Testpublic void test1() {AnimalFactory1 factory = new AnimalFactory1();Animal a1 = factory.createAnimal("cat");Animal a2 = factory.createAnimal("dog");a1.eat();a2.eat();}@Testpublic void test2() {AnimalFactory2 factory = new AnimalFactory2();Animal a1 = factory.createCat();Animal a2 = factory.createDog();a1.eat();a2.eat();}@Testpublic void test3() {Animal a1 = AnimalFactory3.createCat();Animal a2 = AnimalFactory3.createDog();a1.eat();a2.eat();}

效果都一样,代码不一样,这样看来是第三种比较好了.