Class Exception

What is difference between ClassNotFoundException and NoClassDefFoundError?

1. ClassNotFoundException is an exception and NoClassDefFoundError is an error.

2. ClassNotFoundException occurs when an application tries to load a class using it name via one of the followings and no class with the name is found.

• • The forName method in class Class

  • The findSystemClass method in class ClassLoader.

  • The loadClass method in class ClassLoader

NoClassDefFoundError is thrown when Class Loader tries to load a class definition statically using "new".

3. NoClassDefFoundError error occur when the source was compiled successfully but class is not available at runtime.

References:

1. Understanding the ClassLoader by Greg Travis (2001)