Java Reflection - Editing Array Length

Question

I was wondering if it is possible to change to change the length of a class\'s integer array using the Java Reflection API. If so, how?

Answer 1

Nope; an array is created with a fixed length.

What you can do is get close by modifying the value of the field with a copy in larger array (using Arrays.copyOf), so long as you know modifying like this won't cause any inconsistency.

/* desired length */
final int desired = ...;
/* the instance of the object containing the int[] field */
final Object inst = ...;
/* the handle to the int[] field */
final Field field = ...;
field.set(inst, Arrays.copyOf((int[]) field.get(inst), desired));