Package 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 905636 2010-02-02 14:03:32Z niallp $

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
private static final long	serialVersionUID	Required for serialization support.

Constructor Summary

Constructors

Constructor	Description
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.

Method Summary

Modifier and Type	Method	Description
private static final String	safeGetClassName(Class cls)	Returns the class name or null if the class is null.

Methods inherited from class java.lang.Throwable

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

Methods inherited from class java.lang.Object

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

Field Details

serialVersionUID

private static final long serialVersionUID

Required for serialization support.

See Also:

• Serializable
• Constant Field Values

Constructor Details

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

Method Details

safeGetClassName

private static final String safeGetClassName(Class cls)

Returns the class name or null if the class is null.

Parameters:

cls - a Class

Returns:

the name of cls, or null if if cls is null.