测试一个类是否包含基于其名称的实例变量 [英] Test if a class contains an instance variable based on its name

问题描述

有时我需要测试哪个类声明了一些变量，是否有另一种方法来测试它，如果具体类包含具有某个名称的变量

Sometimes I need to test which class has declared some variable(s), is there another way how to test that, if concrete class contains variable with some name

try {
   testLocalVariable = (String) (this.getClass().getDeclaredField("testVariable").get(this));
} catch (NoSuchFieldException ex) {
} catch (SecurityException ex) {
} catch (IllegalArgumentException ex) {
} catch (IllegalAccessException ex) {
}

推荐答案

如果我理解正确，您可以在超类中使用此代码来测试子类是否具有 testVariable 字段.

If I understand correctly, you use this code in a superclass to test if a subclass has a testVariable field.

你为什么不简单地添加一个这样的方法?

Why don't you simply add a method like this?

 /**
  * Returns true if the object declares a testVariable field, false otherwise. Subclasses should
  * override this method
  */
protected boolean hasTestVariableField() {
    return false;
}

对我来说似乎更面向对象，不会破坏封装.

Seems much more OO to me, doesn't break encapsulation.

话虽如此，我还是不太明白你一开始为什么需要这个.

That said, I've not really understood why you needed this in the first place.

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