Module java.base
Package java.lang

Class ClassNotFoundException

java.lang.Object
java.lang.Throwable
All Implemented Interfaces:
Serializable
public classClassNotFoundExceptionextendsReflectiveOperationException
Thrown when an application tries to load in a class through its string name using:
  • TheforName method in classClass.
  • ThefindSystemClass method in classClassLoader .
  • TheloadClass method in classClassLoader.

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 thegetException() method is now known as thecause, and may be accessed via theThrowable.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 aClassNotFoundException with no detail message.

    • ClassNotFoundException

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

    • ClassNotFoundException

      public ClassNotFoundException​(String s,Throwable ex)
      Constructs aClassNotFoundException 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, returnsnull.

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

      Returns:
      theException that was raised while loading a class
      Since:
      1.2