Java Decorator模式：我可以装饰一个受保护的方法吗？ [英] Java Decorator Pattern: Can I decorate a protected method?

问题描述

我想要装饰（装饰设计模式）一个普通的基类，但是我需要装饰的方法是受保护的。参见示例：

I want to Decorate (Decorator design pattern) a common base class, but the method I need to Decorate is protected. See example:

public class AbstractActor {
   public void act(){...}      //Delegates its actions to doAct() based on some internal logic
   protected void doAct(){...}
}

子类旨在覆盖doAct（），我需要注入一些功能。我可以覆盖doAct，但是我的装饰器类无法访问正在装饰的实例上的受保护方法doAct（）。示例：

Subclasses are meant to override doAct(), I need to inject some functionality there. I can override doAct, but my decorator class can't access the protected method doAct() on the instance being decorated. Example:

public class ActorDecorator extends AbstractActor {
   AbstractActor decoratedInstance;
   public ActorDecorator(AbstractActor decoratedInstance){
      this.decoratedInstance = decoratedInstance;
   }
   protected void doAct(){
      //Inject my code
      decoratedInstance.doAct();    //Can't call protected method of decoratedInstance
   }
   //Other decorator methods
}

有没有解决这个难题？

推荐答案

如果你把在同一个包中的AbstractActor 和 ActorDecorator ，您将可以访问受保护的方法。

If you put AbstractActor and ActorDecorator in the same package, you will be able to access the protected method.

这篇关于Java Decorator模式：我可以装饰一个受保护的方法吗？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！