Class java.lang.NoClassDefFoundError

java.lang.Object
   |
   +----java.lang.Throwable
           |
           +----java.lang.Error
                   |
                   +----java.lang.LinkageError
                           |
                           +----java.lang.NoClassDefFoundError

public class NoClassDefFoundError
extends LinkageError

Thrown if the Java Virtual Machine or a classloader tries to load in the definition of a class (as part of a normal method call or as part of creating a new instance using the new expression) and no definition of the class could be found.

The searched-for class definition existed when the currently executing class was compiled, but the definition can no longer be found.