Java工厂模式的使用细则介绍

public interface Pet {
    void shout();
}
public class Cat implements Pet{
    public void shout() {
        System.out.println("猫叫");
    }
}
public class Dog implements Pet{
    public void shout() {
        System.out.println("狗叫");
    }
}
// 宠物工厂
public class PetFactory {
    // 方式一
    public static Pet getPet(String pet) {
        if (pet.equals("小猫")) {
            return new Cat();
        } else if (pet.equals("小狗")) {
            return new Dog();
        } else {
            return null;
        }
    }
    // 方式二
    public static Pet getCat(){
        return new Cat();
    }
    public static Pet getDog(){
        return new Dog();
    }
}
// 用户类
public class Customer {
    public static void main(String[] args) {
        Pet pet = PetFactory.getPet("小猫");
        pet.shout();
    }
}
// 输出 ： 猫叫

public interface Pet {
    void shout();
}
public class Cat implements Pet {
    public void shout() {
        System.out.println("猫叫");
    }
}
public class CatFactory {
    public static Pet getCat(){
        return new Cat();
    }
}
public class Customer {
    public static void main(String[] args) {
        Pet cat = CatFactory.getCat();
        cat.shout();
    }
}

// 工厂接口
public interface ProductFactory {
    RouterProduct getRouter();  // 生产路由器
    PhoneProduct getPhone();   // 生产手机
}
// 手机、路由器接口
public interface PhoneProduct { void close();}
public interface RouterProduct {void start();}
// 工厂
public class HuaweiFactory implements ProductFactory{
  public RouterProduct getRouter() {return new HuaweiRouter();}
  public PhoneProduct getPhone() {
    return new HuaweiPhone();
  }
}
public class XiaoMiFactory implements ProductFactory{
  public RouterProduct getRouter() {
    return new XiaoMiRouter();
  }
  public PhoneProduct getPhone() {
    return new XiaoMiPhone();
  }
}
// 测试
public static void main(String[] args) {
  // 拿到工厂对象
  XiaoMiFactory miFactory = new XiaoMiFactory();
  HuaweiFactory huaweiFactory = new HuaweiFactory();
  // 小米工厂生产
  PhoneProduct miFactoryPhone = miFactory.getPhone();
  miFactoryPhone.close();
  RouterProduct router = miFactory.getRouter();
  router.start();
  // 华为工厂生产
  PhoneProduct phone = huaweiFactory.getPhone();
  phone.close();
  RouterProduct router1 = huaweiFactory.getRouter();
  router1.start();
}