org.exolab.castor.mapping.loader
Class FieldHandlerFriend

java.lang.Object
  org.exolab.castor.mapping.loader.FieldHandlerFriend

All Implemented Interfaces:

FieldHandler

Direct Known Subclasses:

ExtendedFieldHandler

public abstract class FieldHandlerFriend
extends Object
implements FieldHandler

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

Version:

$Revision: 8775 $ $Date: 2005-08-03 15:11:51 -0600 (Wed, 03 Aug 2005) $

Author:

Keith Visco

See Also:

FieldDescriptor, FieldHandler

Constructor Summary

FieldHandlerFriend()

Method Summary

abstract void	checkValidity(Object object) Deprecated. No longer supported
protected abstract FieldDescriptor	getFieldDescriptor() Returns the FieldDescriptor for the field that this handler is responsible for, or null if no FieldDescriptor has been set.
abstract Object	getValue(Object object) Returns the value of the field from the object.
abstract Object	newInstance(Object parent) Creates a new instance of the object described by this field.
abstract void	resetValue(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(Object object, 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

FieldHandlerFriend

public FieldHandlerFriend()

Method Detail

getFieldDescriptor

protected abstract FieldDescriptor getFieldDescriptor()

Returns the FieldDescriptor for the field that this handler is responsible 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.

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.

Parameters:

fieldDesc - the FieldDescriptor to set

checkValidity

public abstract void checkValidity(Object object)
                            throws ValidityException,
                                   IllegalStateException

Deprecated. No longer supported

Specified by:

checkValidity in interface FieldHandler

Throws:

ValidityException

IllegalStateException

getValue

public abstract Object getValue(Object object)
                         throws IllegalStateException

Returns the value of the field from the object.

Specified by:

getValue in interface FieldHandler

Parameters:

object - The object

Returns:

The value of the field

Throws:

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 Object newInstance(Object parent)
                            throws IllegalStateException

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

Specified by:

newInstance in interface FieldHandler

Parameters:

parent - The object for which the field is created

Returns:

A new instance of the field's value

Throws:

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

resetValue

public abstract void resetValue(Object object)
                         throws IllegalStateException,
                                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

Parameters:

object - The object

Throws:

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

IllegalArgumentException

setValue

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

Sets the value of the field on the object.

Specified by:

setValue in interface FieldHandler

Parameters:

object - The object

value - The new value

Throws:

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

IllegalArgumentException - The value passed is not of a supported type