访问其类类型是动态已知的对象的方法和函数 [英] Accessing Methods and functions of a object whose class type is dynamically known

问题描述

我有一个类型为A的对象A1。我动态地发现，对象A1是A类。我现在有一个属性说我要从A1访问的名称，我该怎么做？

现在最大的问题是对象A1甚至可能是类型B.如果它是类型B，那么我将必须获取值地址。现在我如何解决这个问题？

下面的代码是类型检查，

  
 public static void testing（Object A1，String s）s  -  Classtype 
 {
 try {
 Class c = Class.forName（s）; 
 
 if（c.isInstance（A1））// 
 {
 //现在我知道A1是类型C.但是我不知道什么类型的'c'是（不管类型A还是类型B.因为只有那时我可以访问相应的成员。）像我说的，类型A包含'name'，类型B包含地址。 
 //访问不仅可以是成员，也可以是一种方法。 
} 
} catch（Exception e）{System.out.println（e）;} 
} 
  

任何指针都会帮助很多。谢谢

解决方案

你可以知道类的声明字段

 类cls = Class.forName（MyClass）; 
 Field fieldlist [] = cls.getDeclaredFields（）; 
  

• 文档

I have an object A1 of type A. I dynamically find that out , that object A1 is of type A. I now have a property say "Name" which I want to access from A1 , how do I do it ?

Now the biggest problem is that the object A1 can even be of type B. If it is of type B then I will have to obtain the value "Address". Now How I resolve this ?

Below code does the type check ,

public static void testing(Object A1, String s) s - Classtype
  {
      try{
          Class c = Class.forName(s);

          if( c.isInstance(A1)) // 
          {
              //Now I know that A1 is of the  type C. But I dont know what type 'c' is (whether type A or type B. Because Only then I can access the appropriate member.) Like I said, type A contain 'name' and type B contains address.
              // The access may not only be a member but also a method .
          }
      }catch (Exception e){ System.out.println(e);}
  }

Any pointers would help a lot . thanks

解决方案

You can know the declared fields of class

 Class cls = Class.forName("MyClass");
 Field fieldlist[] = cls.getDeclaredFields();  

• Documentation

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