org.exolab.castor.mapping.loader

Class FieldHandlerImpl<T>

java.lang.Object

org.exolab.castor.mapping.loader.FieldHandlerFriend<T>

org.exolab.castor.mapping.ExtendedFieldHandler<T>

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

org.exolab.castor.mapping.loader.FieldHandlerImpl<T>

All Implemented Interfaces:

ConfigurableFieldHandler<T>, FieldHandler<T>

public final class FieldHandlerImpl<T>
extends AbstractFieldHandler<T>

A field handler that knows how to get/set the values of a field directly or through the get/set methods. Uses reflection.

Note: the field Java type is obtained from TypeInfo.getFieldType(), but if the field is a collection, the actual field/accessor type is obtained from TypeInfo.getCollectionHandler() and the object to create (with newInstance(Object)) is the former field type.

Version:

$Revision$ $Date: 2006-04-25 15:08:23 -0600 (Tue, 25 Apr 2006) $

Author:

Assaf Arkin

Field Summary

Fields inherited from class org.exolab.castor.mapping.AbstractFieldHandler

_properties

Constructor Summary

Constructors

Constructor and Description
FieldHandlerImpl(FieldHandler<T> handler, TypeInfo typeInfo) Construct a new field handler for the specified field.
FieldHandlerImpl(Field field, TypeInfo typeInfo) Construct a new field handler for the specified field.
FieldHandlerImpl(String fieldName, Method[] getSequence, Method[] setSequence, Method getMethod, Method setMethod, TypeInfo typeInfo) Construct a new field handler for the specified field that is accessed through the accessor methods (get/set).

Method Summary

Modifier and Type	Method and Description
TypeConvertor	getConvertFrom()
TypeConvertor	getConvertTo()
T	getValue(Object object) Returns the value of the field from the object.
boolean	isCollection() Return true if the field is a collection.
T	newInstance(Object parent) Creates a new instance of the object described by this field.
T	newInstance(Object parent, Object[] args) Creates a new instance of the object described by this field.
void	resetValue(Object object) Sets the value of the field to a default value.
void	setAddMethod(Method method) Mutator method used by Introspector.
void	setConvertFrom(TypeConvertor convertor) Sets the TypeConvertor used during calls to getValue
void	setConvertTo(TypeConvertor convertor) Sets the TypeConvertor used during calls to setValue
void	setCreateMethod(Method method) Mutator method used by AbstractMappingLoader and Introspector.
void	setEnumMethod(Method method) Sets the enumeration method.
void	setFieldDescriptor(FieldDescriptor fieldDesc) Sets the FieldDescriptor that this FieldHander is responsibile for.
void	setHasDeleteMethod(Method hasMethod, Method deleteMethod) Mutator method used by AbstractMappingLoader and Introspector.
void	setIterMethod(Method method) Sets the iteration method.
void	setReadMethod(Method method) Mutator method used by Introspector.
void	setValue(Object object, T value) Sets the value of the field on the object.
void	setWriteMethod(Method method) Mutator method used by Introspector.
String	toString()

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

getFieldDescriptor, hasValue, setConfiguration

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

checkValidity

Methods inherited from class java.lang.Object

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

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

checkValidity

Constructor Detail

FieldHandlerImpl

public FieldHandlerImpl(FieldHandler<T> handler,
                        TypeInfo typeInfo)

Construct a new field handler for the specified field. The field must be public, and may not be static or transient. The field name is determined from the Java field, the type from the type information.

Parameters:

handler -

typeInfo - Type information

FieldHandlerImpl

public FieldHandlerImpl(Field field,
                        TypeInfo typeInfo)
                 throws MappingException

Construct a new field handler for the specified field. The field must be public, and may not be static or transient. The field name is determined from the Java field, the type from the type information.

Parameters:

field - The field being described

typeInfo - Type information

Throws:

MappingException - If the field is not public, is static or transient

FieldHandlerImpl

public FieldHandlerImpl(String fieldName,
                        Method[] getSequence,
                        Method[] setSequence,
                        Method getMethod,
                        Method setMethod,
                        TypeInfo typeInfo)
                 throws MappingException

Construct a new field handler for the specified field that is accessed through the accessor methods (get/set). The accessor methods must be public and not static. The field name is required for descriptive purposes. The field type must match the return value of the get method and the single parameter of the set method. Either get or set methods are optional.

Parameters:

fieldName - The field being described

getMethod - The method used to retrieve the field value, must accept no parameters and have a return type castable to the field type

setMethod - The method used to set the field value, must accept a single parameter that is castable to the field type

typeInfo - Type information

Throws:

MappingException - If the get or set method are not public, are static, or do not specify the proper types

Method Detail

getConvertFrom

public TypeConvertor getConvertFrom()

getConvertTo

public TypeConvertor getConvertTo()

getValue

public T getValue(Object object)

Returns the value of the field from the object.

Parameters:

object - The object

Returns:

The value of the field

See Also:

FieldHandler.getValue(java.lang.Object)

setValue

public void setValue(Object object,
                     T value)

Sets the value of the field on the object.

Parameters:

object - The object.

value - The new value.

See Also:

FieldHandler.setValue(java.lang.Object, java.lang.Object)

resetValue

public void resetValue(Object object)

Description copied from interface: FieldHandler

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.

Parameters:

object - The object.

newInstance

public T newInstance(Object parent)
              throws IllegalStateException

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

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

newInstance

public T newInstance(Object parent,
                     Object[] args)
              throws IllegalStateException

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

Specified by:

newInstance in class ExtendedFieldHandler<T>

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:

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

setConvertFrom

public void setConvertFrom(TypeConvertor convertor)

Sets the TypeConvertor used during calls to getValue

Parameters:

convertor - the TypeConvertor to use during calls to getValue

setConvertTo

public void setConvertTo(TypeConvertor convertor)

Sets the TypeConvertor used during calls to setValue

Parameters:

convertor - the TypeConvertor to use during calls to setValue

setCreateMethod

public void setCreateMethod(Method method)
                     throws MappingException

Mutator method used by AbstractMappingLoader and Introspector. Please understand how this method is used before you start playing with it! :-)

Throws:

MappingException

setHasDeleteMethod

public void setHasDeleteMethod(Method hasMethod,
                               Method deleteMethod)
                        throws MappingException

Mutator method used by AbstractMappingLoader and Introspector. Please understand how this method is used before you start playing with it! :-)

Throws:

MappingException

setReadMethod

public void setReadMethod(Method method)
                   throws MappingException

Mutator method used by Introspector. Please understand how this method is used before you start playing with it! :-)

Throws:

MappingException

setWriteMethod

public void setWriteMethod(Method method)
                    throws MappingException

Mutator method used by Introspector. Please understand how this method is used before you start playing with it! :-)

Throws:

MappingException

setAddMethod

public void setAddMethod(Method method)
                  throws MappingException

Mutator method used by Introspector. Please understand how this method is used before you start playing with it! :-)

Throws:

MappingException

setEnumMethod

public void setEnumMethod(Method method)
                   throws MappingException

Sets the enumeration method.

Throws:

MappingException

setIterMethod

public void setIterMethod(Method method)
                   throws MappingException

Sets the iteration method.

Throws:

MappingException

isCollection

public boolean isCollection()

Return true if the field is a collection.

toString

public String toString()

Overrides:

toString in class Object

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.

Overrides:

setFieldDescriptor in class AbstractFieldHandler<T>

Parameters:

fieldDesc - the FieldDescriptor to set