ClassNotFoundException in Java — What It Means and How to Fix It
What Java's ClassNotFoundException means and how to fix it.
Published November 3, 2026
ClassNotFoundException is a checked exception thrown when code tries to load a class by name (e.g. via Class.forName()) and it can't be found.
Key points
- Read the full stack trace from the top — it names the exact class, method, and line where the exception originated
Example
Usually indicates a missing dependency on the classpath at runtime