Module java.base
Package java.lang

Class ClassNotFoundException

All Implemented Interfaces:
Serializable

public class ClassNotFoundException
extends ReflectiveOperationException
Thrown when an application tries to load in a class through its string name using:
  • The forName method in class Class.
  • The findSystemClass method in class ClassLoader .
  • The loadClass method in class ClassLoader.

but no definition for the class with the specified name could be found.

As of release 1.4, this exception has been retrofitted to conform to the general purpose exception-chaining mechanism. The "optional exception that was raised while loading the class" that may be provided at construction time and accessed via the getException() method is now known as the cause, and may be accessed via the Throwable.getCause() method, as well as the aforementioned "legacy method."

Since:
1.0
See Also:
Class.forName(java.lang.String), ClassLoader.findSystemClass(java.lang.String), ClassLoader.loadClass(java.lang.String, boolean), Serialized Form
  • Constructor Details

    • ClassNotFoundException

      public ClassNotFoundException()
      Constructs a ClassNotFoundException with no detail message.
    • ClassNotFoundException

      public ClassNotFoundException​(String s)
      Constructs a ClassNotFoundException with the specified detail message.
      Parameters:
      s - the detail message.
    • ClassNotFoundException

      public ClassNotFoundException​(String s, Throwable ex)
      Constructs a ClassNotFoundException with the specified detail message and optional exception that was raised while loading the class.
      Parameters:
      s - the detail message
      ex - the exception that was raised while loading the class
      Since:
      1.2
  • Method Details

    • getException

      public Throwable getException()
      Returns the exception that was raised if an error occurred while attempting to load the class. Otherwise, returns null.

      This method predates the general-purpose exception chaining facility. The Throwable.getCause() method is now the preferred means of obtaining this information.

      Returns:
      the Exception that was raised while loading a class
      Since:
      1.2