Java Interview Question - Can You Modify a Final Field using Reflection?
Reflection, Concept, Coding and more ...
Yes, it is sometimes possible to modify a final field using reflection, but not always, and even when it works, it is unreliable, JVM-dependent, and absolutely discouraged in real systems. Also, there is work in JDK 26 to remove this in the long term.
When can it work?
But first, when we talk about the final, there are three main scenarios:
1. Non-static final fields - tied to object instance
2. Static final compile-time constants - primitive or String literals that the compiler inlines
3. Static final non-constant references - objects or boxed types initialized at runtime
Each behaves differently when reflection comes into play.
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1.Non-static final fields — technically mutable
Surprisingly, Java allows reflective modification of non-static final fields in many versions, including Java 25:
This works for instance fields, because they aren’t compile-time constants.
