抽象工厂模式
一、定义
为创建一组相关或相互依赖的对象提供一个接口，而无需指定它们的具体类。
二、类图表示
三、实现
1、Factory
package pattern.creational.abstractfactory;
/**
* 抽象动物工厂
*/
public abstract class AbstractAnimalFactory {
//创建食草动物
public abstract Herbivore createHerbivore();
//创建食肉动物
public abstract Carnivore createCarnivore();
}
package pattern.creational.abstractfactory;
/**
* 亚洲动物工厂
*/
public class AsiaAnimalFactory extends AbstractAnimalFactory {
@Override
public Herbivore createHerbivore() {
return new Deer();
}
@Override
public Carnivore createCarnivore() {
return new Tiger();
}
}
package pattern.creational.abstractfactory;
/**
* 非洲动物工厂
*/
public class AfricaAnimalFactory extends AbstractAnimalFactory {
@Override
public Herbivore createHerbivore() {
return new Antelope();
}
@Override
public Carnivore createCarnivore() {
return new Cheetah();
}
}
2、Product
package pattern.creational.abstractfactory;
/**
* 食肉动物
*/
public abstract class Carnivore {
public abstract void eat(Herbivore herbivore);
}
package pattern.creational.abstractfactory;
/**
* 食草动物
*/
public abstract class Herbivore {
}
package pattern.creational.abstractfactory;
public class Tiger extends Carnivore {
@Override
public void eat(Herbivore herbivore) {
System.out.println(String.format("%s 在亚洲森林中捕食 %s", this, herbivore));
}
@Override
public String toString() {
return "老虎";
}
}
package pattern.creational.abstractfactory;
public class Cheetah extends Carnivore {
@Override
public void eat(Herbivore herbivore) {
System.out.println(String.format("%s 在非洲大草原上追捕 %s", this, herbivore));
}
@Override
public String toString() {
return "猎豹";
}
}
package pattern.creational.abstractfactory;
public class Deer extends Herbivore {
@Override
public String toString() {
return "鹿";
}
}
package pattern.creational.abstractfactory;
public class Antelope extends Herbivore {
@Override
public String toString() {
return "羚羊";
}
}
四、使用
package pattern.creational.abstractfactory;
public class AnimalWorld {
private Herbivore herbivore;
private Carnivore canivore;
public AnimalWorld(AbstractAnimalFactory factory) {
this.herbivore = factory.createHerbivore();
this.canivore = factory.createCarnivore();
}
public void play(){
canivore.eat(herbivore);
}
}
package pattern.creational.abstractfactory;
public class Client {
public static void main(String[] args) {
//亚洲
AbstractAnimalFactory factory = new AsiaAnimalFactory();
AnimalWorld world = new AnimalWorld(factory);
world.play();
//非洲
factory = new AfricaAnimalFactory();
world = new AnimalWorld(factory);
world.play();
}
}
- 程序输出：
老虎 在亚洲森林中捕食 鹿
猎豹 在非洲大草原上追捕 羚羊
五、适用场合
- 创建一系列相关产品时使用
- 只想显示提供的产品类库的接口而不是实现时