org.exolab.castor.mapping
Class AbstractFieldHandler<T>

java.lang.Object
  org.exolab.castor.mapping.loader.FieldHandlerFriend<T>
      org.exolab.castor.mapping.ExtendedFieldHandler<T>
          org.exolab.castor.mapping.AbstractFieldHandler<T>

All Implemented Interfaces:

ConfigurableFieldHandler<T>, FieldHandler<T>

Direct Known Subclasses:

FieldHandlerImpl, GeneralizedFieldHandler, TransientFieldHandler, XMLFieldHandler

public abstract class AbstractFieldHandler<T>
extends ExtendedFieldHandler<T>
implements ConfigurableFieldHandler<T>

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

Version:

$Revision: 9062 $ $Date: 2005-08-03 15:11:51 -0600 (Wed, 03 Aug 2005) $

Author:

Keith Visco

See Also:

FieldDescriptor, FieldHandler

Field Summary

protected Properties

_properties Configuration that can be used by subclasses when needed.

Constructor Summary

AbstractFieldHandler()

Method Summary

protected FieldDescriptor	getFieldDescriptor() Returns the FieldDescriptor for the field that this handler is responsible for, or null if no FieldDescriptor has been set.
boolean	hasValue(Object object) Returns true if the "handled" field has a value within the given object.
void	setConfiguration(Properties config) Empty implementation of the ConfigurableFieldHandler interface, for convenience purpose.
void	setFieldDescriptor(FieldDescriptor fieldDesc) Sets the FieldDescriptor that this FieldHander is responsibile for.

Methods inherited from class org.exolab.castor.mapping.ExtendedFieldHandler

checkValidity, newInstance

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.exolab.castor.mapping.FieldHandler

checkValidity, getValue, newInstance, resetValue, setValue

Field Detail

_properties

protected Properties _properties

Configuration that can be used by subclasses when needed.

Constructor Detail

AbstractFieldHandler

public AbstractFieldHandler()

Method Detail

getFieldDescriptor

protected final 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.

Specified by:

getFieldDescriptor in class FieldHandlerFriend<T>

Returns:

the FieldDescriptor, or null if none exists.

setFieldDescriptor

public 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<T>

Parameters:

fieldDesc - the FieldDescriptor to set

hasValue

public boolean hasValue(Object object)

Returns true if the "handled" field has a value within the given object.

By default this just checks for null. Normally this method is needed for checking if a value has been set via a call to the setValue method, or if the primitive value has been initialised by the JVM.

This method should be overloaded for improved value checking.

Returns:

true if the given object has a value for the handled field

setConfiguration

public void setConfiguration(Properties config)
                      throws ValidityException

Empty implementation of the ConfigurableFieldHandler interface, for convenience purpose. Subclasses that want to use any configuration should override this method.

Specified by:

setConfiguration in interface ConfigurableFieldHandler<T>

Parameters:

config - The configuration as specified in the mapping file.

Throws:

ValidityException - if config is invalid for this FieldHandler.