Java reflection - getting fields from a subclass as well as a superclass

Question

I am using legacy bean classes for my project. Here, some superclasses will be empty, and the subclass may have fields, and some of the subclasses will be empty, and the superclass may have fields.

My requirement is to get all private / public fields from the Sub class, and also get all public / protected fields from the Super class.

Below I tried to achieve it. But I could not satisfy my requirements. Please provide some suggestion to achieve this.

Field fields [] = obj.getClass().getSuperclass().getDeclaredFields(); 

If I use the code above, I can only get Superclass fields

 Field fields [] = obj.getClass().getFields(); 

If I use the code above, I can get all the fields from the Sub class and super class fields

 Field fields [] = obj.getClass().getDeclaredFields(); 

If I use the code above, I can get the Sub class public and private all fields.

Answer 1

You will have to iterate over all the superclasses of your class, for example:

 private List<Field> getInheritedPrivateFields(Class<?> type) { List<Field> result = new ArrayList<Field>(); Class<?> i = type; while (i != null && i != Object.class) { Collections.addAll(result, i.getDeclaredFields()); i = i.getSuperclass(); } return result; }