关于工厂设计模式通过反思 [英] Regarding factory design pattern through reflection

问题描述

我正在做R& D工厂模式，我开发了以下代码，仪式现在我知道这些子类是狗和猫，但是如果我想通过反思传递相同的东西，请告诉我该怎么办main.java中的类名称

  public abstract class Animal {
 public abstract String makeSound（）; 
} 
 
 public class Dog extends Animal {
 
 @Override 
 public String makeSound（）{
 returnWoof; 
} 
 
} 
 
 public class Cat extends Animal {
 
 @Override 
 public String makeSound（）{
返回喵; 
} 
 
} 
 
 public class AnimalFactory {
 
 public Animal getAnimal（String type）{
 if（canine .equals（type））{
 return new Dog（）; 
} else {
返回新的Cat（）; 
} 
} 
 
} 
 
 public class Main {
 
 public static void main（String [] args）{ 
 AnimalFactory animalFactory = new AnimalFactory（）; 
 
动物a1 = animalFactory.getAnimal（feline）; 
 System.out.println（a1 sound：+ a1.makeSound（））; 
 
动物a2 = animalFactory.getAnimal（canine）; 
 System.out.println（a2 sound：+ a2.makeSound（））; 
} 
 
} 
  

请告诉我如何添加反射功能进入它，使我不需要甚至确定类型，只是传递类的名称在主java和该子类的对象获得创建

解决方案

为此，您的 Cat 和 Dog 类必须在自己的文件中在包 your.package 并具有默认构造函数：

  public class AnimalFactory {
 public Animal getAnimal（String type）{
 return（Animal）Class.forName（your.package。+ type）.newInstance（）; 
} 
} 
  

I was doing R&D on factory pattern I have developed the below code ,rite now I know the subclasses are Dog and Cat , but please advise me what to do if the same thing I want to achieve through reflection by passing the class name in main.java

    public abstract class Animal {
    public abstract String makeSound();
}

public class Dog extends Animal {

    @Override
    public String makeSound() {
        return "Woof";
    }

}

public class Cat extends Animal {

    @Override
    public String makeSound() {
        return "Meow";
    }

}

public class AnimalFactory {

    public Animal getAnimal(String type) {
        if ("canine".equals(type)) {
            return new Dog();
        } else {
            return new Cat();
        }
    }

}

public class Main {

    public static void main(String[] args) {
        AnimalFactory animalFactory = new AnimalFactory();

        Animal a1 = animalFactory.getAnimal("feline");
        System.out.println("a1 sound: " + a1.makeSound());

        Animal a2 = animalFactory.getAnimal("canine");
        System.out.println("a2 sound: " + a2.makeSound());
    }

}

Please advise it how I can add reflection functionality into it so that I don't need to even determine the type , just pass the class name in the main java and object of that subclass get created

解决方案

For this to work, your Cat and Dog classes must be in their own files in the package your.package and have default constructors:

public class AnimalFactory {
    public Animal getAnimal(String type) {
        return (Animal) Class.forName("your.package." + type).newInstance();
    }
}

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