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
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