Accessing non-visible classes with reflection

Question

I am trying to get an instance of a non-visible class, AKA package private class, using reflection. I was wondering if there was a way to switch the modifiers to make it pu

Answer 1

I had requirement to copy the value of field from older version of object if the value is null in latest version. We had these 2 options.

Core Java :

for (Field f : object.getClass().getSuperclass().getDeclaredFields()) {
    f.setAccessible(true);
  System.out.println(f.getName());
  if (f.get(object) == null){
    f.set(object, f.get(oldObject));
  }
}

Using Spring [org.springframework.beans.BeanWrapper] :

BeanWrapper bw = new BeanWrapperImpl(object);
PropertyDescriptor[] data = bw.getPropertyDescriptors();
for (PropertyDescriptor propertyDescriptor : data) {
  System.out.println(propertyDescriptor.getName());
  Object propertyValue = bw.getPropertyValue(propertyDescriptor.getName());
  if(propertyValue == null )
    bw.setPropertyValue( new PropertyValue(propertyDescriptor.getName(),"newValue"));
}