Use reflection to repeat classes

Question

I have a class with numerous parameters of different types. I want to iterate over all elements of type A and run certain functions (A.doSomething ())

It doesn't even compile: conversion from field to XPathDataElement is illegal

Field[] fields = this.getClass().getDeclaredFields();
  for (Field field : fields) {
     if (field. getType().getName().equals(XPathDataElement.class.getName()))
        {               
                tmp = (XPathDataElement)field; // Doesn't compile
                sb.append(field.getName() + ":"); 
                tmp.update();
        }
    }

Thanks!

Answer 1

It's hard to debug your code unless you say what is wrong with it.

Two things that I see:

• There is no need to compare strings to determine if the field type is the correct class.

  if (field.getType().equals(XPathDataElement.class))
  

  must work.

  : , XPathDataElement; . , XPathDataElement, Class.isAssignableFrom(Class).

  if (XPathDataElement.class.isAssignableFrom(field.getType()))
  

  .

• , - ? , Field.get(Object) - , . , get(), , ; this ( ),

  XPathDataElement tmp = (XPathDataElement) field.get(this);
  

Answer 2

, .

:

this.x.doSomething();
this.y.doSomething();
this.z.doSomething();

, :

for (A a : new A[] {
    this.x, this.y, this.z
}) {
    a.doSomething();
}

Answer 3

:

• , .

  field.getType(). (XPathDataElement.class)

• , isAssignableFrom(java.lang.Class) , ,

  XPathDataElement.class.isAssignableFrom(field.getType())

• You repeat the fields , not the method . Your question makes me suggest that you want the latter, and if so, use:

  this.getClass (). GetDeclaredMethods ()

Answer 4

It seems you are not assigning anything objyou passed in XPathDataElementin the loop.

You probably want to do something like this:

tmp = (XPathDataElement)field.get(this);