oracle.toplink.essentials.internal.indirection

Class BasicIndirectionPolicy

java.lang.Object

oracle.toplink.essentials.internal.indirection.IndirectionPolicy

oracle.toplink.essentials.internal.indirection.BasicIndirectionPolicy

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable

Direct Known Subclasses:

WeavedObjectBasicIndirectionPolicy

public class BasicIndirectionPolicy
extends IndirectionPolicy

Purpose

: BasicIndirectionPolicy implements the behavior necessary for a a ForeignReferenceMapping (or TransformationMapping) to use ValueHolders to delay the reading of objects from the database until they are actually needed.

Since:

TOPLink/Java 2.5

Author:

Mike Norman

See Also:

ForeignReferenceMapping, Serialized Form

Field Summary

Fields inherited from class oracle.toplink.essentials.internal.indirection.IndirectionPolicy

mapping

Constructor Summary

Constructors

Constructor and Description
BasicIndirectionPolicy() INTERNAL: Construct a new indirection policy.

Method Summary

Modifier and Type	Method and Description
java.lang.Object	backupCloneAttribute(java.lang.Object attributeValue, java.lang.Object clone, java.lang.Object backup, UnitOfWorkImpl unitOfWork) INTERNAL: Return a backup clone of the attribute.
java.lang.Object	cloneAttribute(java.lang.Object attributeValue, java.lang.Object original, java.lang.Object clone, UnitOfWorkImpl unitOfWork, boolean buildDirectlyFromRow) INTERNAL: Return a clone of the attribute.
java.util.Vector	extractPrimaryKeyForReferenceObject(java.lang.Object referenceObject, AbstractSession session) INTERNAL: Return the primary key for the reference object (i.e.
AbstractRecord	extractReferenceRow(java.lang.Object referenceObject) INTERNAL: Return the reference row for the reference object.
java.lang.Object	getOriginalIndirectionObject(java.lang.Object unitOfWorkIndirectionObject, AbstractSession session) INTERNAL: Return the original indirection object for a unit of work indirection object.
java.lang.Object	getRealAttributeValueFromObject(java.lang.Object object, java.lang.Object attribute) INTERNAL: Return the "real" attribute value, as opposed to any wrapper.
void	iterateOnAttributeValue(DescriptorIterator iterator, java.lang.Object attributeValue) INTERNAL: Iterate over the specified attribute value,
java.lang.Object	nullValueFromRow() INTERNAL: Return the null value of the appropriate attribute.
boolean	objectIsInstantiated(java.lang.Object object) INTERNAL: Return whether the specified object is instantiated.
void	setRealAttributeValueInObject(java.lang.Object target, java.lang.Object attributeValue) INTERNAL: Set the value of the appropriate attribute of target to attributeValue.
protected boolean	typeIsValid(java.lang.Class attributeType) INTERNAL: Return whether the type is appropriate for the indirection policy.
java.lang.Object	validateAttributeOfInstantiatedObject(java.lang.Object attributeValue) INTERNAL: Verify that the value of the attribute within an instantiated object is of the appropriate type for the indirection policy.
void	validateDeclaredAttributeType(java.lang.Class attributeType, IntegrityChecker checker) INTERNAL: Verify that attributeType is correct for the indirection policy.
void	validateGetMethodReturnType(java.lang.Class returnType, IntegrityChecker checker) INTERNAL: Verify that getter returnType is correct for the indirection policy.
void	validateSetMethodParameterType(java.lang.Class parameterType, IntegrityChecker checker) INTERNAL: Verify that setter parameterType is correct for the indirection policy.
java.lang.Object	valueFromQuery(ReadQuery query, AbstractRecord row, AbstractSession session) INTERNAL: Return the value to be stored in the object's attribute.
java.lang.Object	valueFromRow(java.lang.Object object) INTERNAL: Return the value to be stored in the object's attribute.

Methods inherited from class oracle.toplink.essentials.internal.indirection.IndirectionPolicy

buildCascadeQuery, clone, getCollectionMapping, getForeignReferenceMapping, getMapping, getOneToOneMapping, getValueFromProxy, initialize, setMapping, usesIndirection, usesTransparentIndirection, validateContainerPolicy, validateDeclaredAttributeTypeForCollection, validateGetMethodReturnTypeForCollection, validateSetMethodParameterTypeForCollection

Methods inherited from class java.lang.Object

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

Constructor Detail

BasicIndirectionPolicy

public BasicIndirectionPolicy()

INTERNAL: Construct a new indirection policy.

Method Detail

backupCloneAttribute

public java.lang.Object backupCloneAttribute(java.lang.Object attributeValue,
                                             java.lang.Object clone,
                                             java.lang.Object backup,
                                             UnitOfWorkImpl unitOfWork)

INTERNAL: Return a backup clone of the attribute.

Overrides:

backupCloneAttribute in class IndirectionPolicy

cloneAttribute

public java.lang.Object cloneAttribute(java.lang.Object attributeValue,
                                       java.lang.Object original,
                                       java.lang.Object clone,
                                       UnitOfWorkImpl unitOfWork,
                                       boolean buildDirectlyFromRow)

INTERNAL: Return a clone of the attribute.

Specified by:

cloneAttribute in class IndirectionPolicy

Parameters:

buildDirectlyFromRow - indicates that we are building the clone directly from a row as opposed to building the original from the row, putting it in the shared cache, and then cloning the original.

extractPrimaryKeyForReferenceObject

public java.util.Vector extractPrimaryKeyForReferenceObject(java.lang.Object referenceObject,
                                                            AbstractSession session)

INTERNAL: Return the primary key for the reference object (i.e. the object object referenced by domainObject and specified by mapping). This key will be used by a RemoteValueHolder.

Overrides:

extractPrimaryKeyForReferenceObject in class IndirectionPolicy

extractReferenceRow

public AbstractRecord extractReferenceRow(java.lang.Object referenceObject)

INTERNAL: Return the reference row for the reference object. This allows the new row to be built without instantiating the reference object. Return null if the object has already been instantiated.

Specified by:

extractReferenceRow in class IndirectionPolicy

getOriginalIndirectionObject

public java.lang.Object getOriginalIndirectionObject(java.lang.Object unitOfWorkIndirectionObject,
                                                     AbstractSession session)

INTERNAL: Return the original indirection object for a unit of work indirection object. This is used when building a new object from the unit of work when the original fell out of the cache.

Specified by:

getOriginalIndirectionObject in class IndirectionPolicy

getRealAttributeValueFromObject

public java.lang.Object getRealAttributeValueFromObject(java.lang.Object object,
                                                        java.lang.Object attribute)

INTERNAL: Return the "real" attribute value, as opposed to any wrapper. This will trigger the wrapper to instantiate the value.

Specified by:

getRealAttributeValueFromObject in class IndirectionPolicy

iterateOnAttributeValue

public void iterateOnAttributeValue(DescriptorIterator iterator,
                                    java.lang.Object attributeValue)

INTERNAL: Iterate over the specified attribute value,

Overrides:

iterateOnAttributeValue in class IndirectionPolicy

nullValueFromRow

public java.lang.Object nullValueFromRow()

INTERNAL: Return the null value of the appropriate attribute. That is, the field from the database is NULL, return what should be placed in the object's attribute as a result. In this case, return an empty ValueHolder.

Specified by:

nullValueFromRow in class IndirectionPolicy

objectIsInstantiated

public boolean objectIsInstantiated(java.lang.Object object)

INTERNAL: Return whether the specified object is instantiated.

Specified by:

objectIsInstantiated in class IndirectionPolicy

setRealAttributeValueInObject

public void setRealAttributeValueInObject(java.lang.Object target,
                                          java.lang.Object attributeValue)

INTERNAL: Set the value of the appropriate attribute of target to attributeValue. In this case, place the value inside the target's ValueHolder.

Overrides:

setRealAttributeValueInObject in class IndirectionPolicy

typeIsValid

protected boolean typeIsValid(java.lang.Class attributeType)

INTERNAL: Return whether the type is appropriate for the indirection policy. In this case, the attribute type MUST be ValueHolderInterface.

validateAttributeOfInstantiatedObject

public java.lang.Object validateAttributeOfInstantiatedObject(java.lang.Object attributeValue)

INTERNAL: Verify that the value of the attribute within an instantiated object is of the appropriate type for the indirection policy. In this case, the attribute must be non-null and it must be a ValueHolderInterface. If the value is null return a new indirection object to be used for the attribute.

Overrides:

validateAttributeOfInstantiatedObject in class IndirectionPolicy

validateDeclaredAttributeType

public void validateDeclaredAttributeType(java.lang.Class attributeType,
                                          IntegrityChecker checker)
                                   throws DescriptorException

INTERNAL: Verify that attributeType is correct for the indirection policy. If it is incorrect, add an exception to the integrity checker. In this case, the attribute type MUST be ValueHolderInterface.

Overrides:

validateDeclaredAttributeType in class IndirectionPolicy

Throws:

DescriptorException

validateGetMethodReturnType

public void validateGetMethodReturnType(java.lang.Class returnType,
                                        IntegrityChecker checker)
                                 throws DescriptorException

INTERNAL: Verify that getter returnType is correct for the indirection policy. If it is incorrect, add an exception to the integrity checker. In this case, the return type MUST be ValueHolderInterface.

Overrides:

validateGetMethodReturnType in class IndirectionPolicy

Throws:

DescriptorException

validateSetMethodParameterType

public void validateSetMethodParameterType(java.lang.Class parameterType,
                                           IntegrityChecker checker)
                                    throws DescriptorException

INTERNAL: Verify that setter parameterType is correct for the indirection policy. If it is incorrect, add an exception to the integrity checker. In this case, the parameter type MUST be ValueHolderInterface.

Overrides:

validateSetMethodParameterType in class IndirectionPolicy

Throws:

DescriptorException

valueFromQuery

public java.lang.Object valueFromQuery(ReadQuery query,
                                       AbstractRecord row,
                                       AbstractSession session)

INTERNAL: Return the value to be stored in the object's attribute. This value is determined by the query. In this case, wrap the query in a ValueHolder for later invocation.

Specified by:

valueFromQuery in class IndirectionPolicy

valueFromRow

public java.lang.Object valueFromRow(java.lang.Object object)

INTERNAL: Return the value to be stored in the object's attribute. This value is determined by the row. In this case, simply wrap the object in a ValueHolder.

Specified by:

valueFromRow in class IndirectionPolicy