org.apache.commons.lang
Class IllegalClassException

java.lang.Object
  java.lang.Throwable
      java.lang.Exception
          java.lang.RuntimeException
              java.lang.IllegalArgumentException
                  org.apache.commons.lang.IllegalClassException

All Implemented Interfaces:

Serializable

public class IllegalClassException

extends IllegalArgumentException

Thrown when an object is an instance of an unexpected type (a class or interface). This exception supplements the standard IllegalArgumentException by providing a more semantically rich description of the problem.

IllegalClassException represents the case where a method takes in a genericly typed parameter like Object (typically because it has to due to some other interface it implements), but this implementation only actually accepts a specific type, for example String. This exception would be used in place of IllegalArgumentException, yet it still extends it.

 public void foo(Object obj) {
   if (obj instanceof String == false) {
     throw new IllegalClassException(String.class, obj);
   }
   // do something with the string
 }
 

Since:

2.0

Version:

$Id: IllegalClassException.java 437554 2006-08-28 06:21:41Z bayard $

Author:

Matthew Hawthorne, Gary Gregory, Stephen Colebourne

See Also:

Serialized Form

Constructor Summary

IllegalClassException(Class expected, Class actual)
Instantiates with the expected and actual types.

IllegalClassException(Class expected, Object actual)
Instantiates with the expected type, and actual object.

IllegalClassException(String message)
Instantiates with the specified message.

Methods inherited from class java.lang.Throwable

fillInStackTrace, getCause, getLocalizedMessage, getMessage, getStackTrace, initCause, printStackTrace, printStackTrace, printStackTrace, setStackTrace, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

IllegalClassException

public IllegalClassException(Class expected,
                             Object actual)

Instantiates with the expected type, and actual object.

Parameters:

expected - the expected type

actual - the actual object

Since:

2.1

IllegalClassException

public IllegalClassException(Class expected,
                             Class actual)

Instantiates with the expected and actual types.

Parameters:

expected - the expected type

actual - the actual type

IllegalClassException

public IllegalClassException(String message)

Instantiates with the specified message.

Parameters:

message - the exception message