org.exolab.castor.mapping

Class ExtendedFieldHandler

java.lang.Object

org.exolab.castor.mapping.loader.FieldHandlerFriend

org.exolab.castor.mapping.ExtendedFieldHandler

All Implemented Interfaces:

FieldHandler

Direct Known Subclasses:

AbstractFieldHandler

public abstract class ExtendedFieldHandler
extends FieldHandlerFriend

An extended version of the FieldHandler interface which is used for adding additional functionality while preserving backward compatability.

Version:

$Revision: 6216 $ $Date: 2005-08-03 15:11:51 -0600 (Wed, 03 Aug 2005) $

Author:

Keith Visco

See Also:

FieldDescriptor, FieldHandler

Constructor Summary

Constructors

Constructor and Description
ExtendedFieldHandler()

Method Summary

Modifier and Type	Method and Description
void	checkValidity(java.lang.Object object) Deprecated. No longer supported
protected abstract FieldDescriptor	getFieldDescriptor() Returns the FieldDescriptor for the field that this handler is reponsibile for, or null if no FieldDescriptor has been set.
abstract java.lang.Object	getValue(java.lang.Object object) Returns the value of the field from the object.
abstract java.lang.Object	newInstance(java.lang.Object parent) Creates a new instance of the object described by this field.
abstract java.lang.Object	newInstance(java.lang.Object parent, java.lang.Object[] args) Creates a new instance of the object described by this field.
abstract void	resetValue(java.lang.Object object) Sets the value of the field to a default value.
abstract void	setFieldDescriptor(FieldDescriptor fieldDesc) Sets the FieldDescriptor that this FieldHander is responsibile for.
abstract void	setValue(java.lang.Object object, java.lang.Object value) Sets the value of the field on the object.

Methods inherited from class java.lang.Object

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

Constructor Detail

ExtendedFieldHandler

public ExtendedFieldHandler()

Method Detail

getFieldDescriptor

protected abstract FieldDescriptor getFieldDescriptor()

Returns the FieldDescriptor for the field that this handler is reponsibile for, or null if no FieldDescriptor has been set. This method is useful for implementations of the FieldHandler interface that wish to obtain information about the field in order to make the FieldHandler more generic and reusable, or simply for validation purposes.

Specified by:

getFieldDescriptor in class FieldHandlerFriend

Returns:

the FieldDescriptor, or null if none exists.

setFieldDescriptor

public abstract void setFieldDescriptor(FieldDescriptor fieldDesc)

Sets the FieldDescriptor that this FieldHander is responsibile for. By setting the FieldDescriptor, it allows the implementation of the FieldHandler methods to obtain information about the field itself. This allows a particular implementation to become more generic and reusable.

Specified by:

setFieldDescriptor in class FieldHandlerFriend

Parameters:

fieldDesc - the FieldDescriptor to set

checkValidity

public void checkValidity(java.lang.Object object)
                   throws ValidityException,
                          java.lang.IllegalStateException

Deprecated. No longer supported

Specified by:

checkValidity in interface FieldHandler

Specified by:

checkValidity in class FieldHandlerFriend

Throws:

ValidityException

java.lang.IllegalStateException

getValue

public abstract java.lang.Object getValue(java.lang.Object object)
                                   throws java.lang.IllegalStateException

Returns the value of the field from the object.

Specified by:

getValue in interface FieldHandler

Specified by:

getValue in class FieldHandlerFriend

Parameters:

object - The object

Returns:

The value of the field

Throws:

java.lang.IllegalStateException - The Java object has changed and is no longer supported by this handler, or the handler is not compatiable with the Java object

newInstance

public abstract java.lang.Object newInstance(java.lang.Object parent)
                                      throws java.lang.IllegalStateException

Creates a new instance of the object described by this field.

Specified by:

newInstance in interface FieldHandler

Specified by:

newInstance in class FieldHandlerFriend

Parameters:

parent - The object for which the field is created

Returns:

A new instance of the field's value

Throws:

java.lang.IllegalStateException - This field is a simple type and cannot be instantiated

newInstance

public abstract java.lang.Object newInstance(java.lang.Object parent,
                                             java.lang.Object[] args)
                                      throws java.lang.IllegalStateException

Creates a new instance of the object described by this field.

Parameters:

parent - The object for which the field is created

args - the set of constructor arguments

Returns:

A new instance of the field's value

Throws:

java.lang.IllegalStateException - This field is a simple type and cannot be instantiated

resetValue

public abstract void resetValue(java.lang.Object object)
                         throws java.lang.IllegalStateException,
                                java.lang.IllegalArgumentException

Sets the value of the field to a default value.

Reference fields are set to null, primitive fields are set to their default value, collection fields are emptied of all elements.

Specified by:

resetValue in interface FieldHandler

Specified by:

resetValue in class FieldHandlerFriend

Parameters:

object - The object

Throws:

java.lang.IllegalStateException - The Java object has changed and is no longer supported by this handler, or the handler is not compatiable with the Java object

java.lang.IllegalArgumentException

setValue

public abstract void setValue(java.lang.Object object,
                              java.lang.Object value)
                       throws java.lang.IllegalStateException,
                              java.lang.IllegalArgumentException

Sets the value of the field on the object.

Specified by:

setValue in interface FieldHandler

Specified by:

setValue in class FieldHandlerFriend

Parameters:

object - The object.

value - The new value.

Throws:

java.lang.IllegalStateException - The Java object has changed and is no longer supported by this handler, or the handler is not compatiable with the Java object.

java.lang.IllegalArgumentException - The value passed is not of a supported type.