simplefactory简单工厂模式

package com.simplafactory;

public interface Animal {
    public void eat();
}
package com.simplafactory;

public class Cat implements Animal {

    @Override
    public void eat() {
        System.out.println("猫吃鱼");
    }

}
package com.simplafactory;

public class Dog implements Animal {

    @Override
    public void eat() {
        System.out.println("狗吃肉");
    }

}
package com.simplafactory;

public class AnimalDemo {
    public static void main(String[] args) {
//        Dog d=new Dog();
//        Cat c=new Cat();
//        
//        c.eat();
//        d.eat();
//        
//        System.out.println("===============");
        
//        Animal d=new Dog();
//        Animal c=new Cat();
//        d.eat();
//        c.eat();
//        AnimalFactory af=new AnimalFactory();
//        Dog d=af.createDog();
//        Cat c=af.createCat();
//        d.eat();
//        c.eat();
        AnimalFactory af=new AnimalFactory();
        Dog d=(Dog) af.createAnimal("dog");
        Cat c=(Cat) af.createAnimal("cat");
        if(d!=null){
            d.eat();
        }
        if(c!=null){
            c.eat();
        }
        
    }
}
package com.simplafactory;

public class AnimalFactory {
//    public Dog createDog(){
//        return new Dog();
//    }
//    
//    public Cat createCat(){
//        return new Cat();
//    }

    public Animal createAnimal(String name){
        if("cat".equalsIgnoreCase(name)){
            return new Cat();
        }
        else if("dog".equalsIgnoreCase(name)){
            return new Dog();
        }
        return null;
    }
}