org.eclipse.persistence.internal.indirection

Class TransparentIndirectionPolicy

java.lang.Object

org.eclipse.persistence.internal.indirection.IndirectionPolicy

org.eclipse.persistence.internal.indirection.TransparentIndirectionPolicy

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable

public class TransparentIndirectionPolicy
extends IndirectionPolicy

Purpose

: TransparentIndirectionPolicy implements the behavior necessary for a a CollectionMapping to use IndirectContainers to delay the reading of objects from the database until they are actually needed.

Since:

TOPLink/Java 2.5

Author:

Big Country

See Also:

CollectionMapping, IndirectContainer, Serialized Form

Constructor Summary

Constructors

Constructor and Description
TransparentIndirectionPolicy() 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	buildIndirectObject(ValueHolderInterface valueHolder) INTERNAL: This method can be used when an Indirection Object is required to be built from a provided ValueHolderInterface object.
java.lang.Object	cloneAttribute(java.lang.Object attributeValue, java.lang.Object original, CacheKey cacheKey, java.lang.Object clone, java.lang.Integer refreshCascade, AbstractSession cloningSession, boolean buildDirectlyFromRow) Return a clone of the attribute.
java.lang.Object	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.
void	fixObjectReferences(java.lang.Object object, java.util.Map objectDescriptors, java.util.Map processedObjects, ObjectLevelReadQuery query, DistributedSession session) INTERNAL: An object has been serialized from the server to the client.
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	getOriginalIndirectionObjectForMerge(java.lang.Object unitOfWorkIndirectionObject, AbstractSession session) INTERNAL: Return the original indirection object for a unit of work indirection object.
java.lang.Object	getOriginalValueHolder(java.lang.Object unitOfWorkIndirectionObject, AbstractSession session) INTERNAL: Return the original valueHolder object.
java.lang.Object	getRealAttributeValueFromObject(java.lang.Object object, java.lang.Object attribute) INTERNAL: Return the "real" attribute value, as opposed to any wrapper.
java.lang.Boolean	getUseLazyInstantiation()
java.lang.Object	getValueFromRemoteValueHolder(RemoteValueHolder remoteValueHolder) INTERNAL: Extract and return the appropriate value from the specified remote value holder.
void	instantiateObject(java.lang.Object object, java.lang.Object attribute) INTERNAL: Trigger the instantiation of the value.
boolean	isAttributeValueFullyBuilt(java.lang.Object attributeValue) INTERNAL: The method validateAttributeOfInstantiatedObject(Object attributeValue) fixes the value of the attributeValue in cases where it is null and indirection requires that it contain some specific data structure.
void	iterateOnAttributeValue(DescriptorIterator iterator, java.lang.Object attributeValue) INTERNAL: Iterate over the specified attribute value.
void	mergeRemoteValueHolder(java.lang.Object clientSideDomainObject, java.lang.Object serverSideDomainObject, MergeManager mergeManager) INTERNAL Replace the client value holder with the server value holder, after copying some of the settings from the client value holder.
java.lang.Object	nullValueFromRow() INTERNAL: Return the null value of the appropriate attribute.
boolean	objectIsEasilyInstantiated(java.lang.Object object) INTERNAL: Return whether the specified object can be instantiated without database access.
boolean	objectIsInstantiated(java.lang.Object object) INTERNAL: Return whether the specified object is instantiated.
boolean	objectIsInstantiatedOrChanged(java.lang.Object object) INTERNAL: Return whether the specified object is instantiated, or if it has changes.
static void	setDefaultContainerSize(int defaultSize) ADVANCED: Set the size to of container to create.
void	setRealAttributeValueInObject(java.lang.Object target, java.lang.Object attributeValue) INTERNAL: Set the value of the appropriate attribute of target to attributeValue.
void	setSourceObject(java.lang.Object sourceObject, java.lang.Object attributeValue) INTERNAL: set the source object into QueryBasedValueHolder.
void	setUseLazyInstantiation(java.lang.Boolean useLazyInstantiation) ADVANCED: IndirectList and IndirectSet can be configured not to instantiate the list from the database when you add and remove from them.
java.lang.Boolean	shouldUseLazyInstantiation() ADVANCED: IndirectList and IndirectSet can be configured not to instantiate the list from the database when you add and remove from them.
boolean	usesTransparentIndirection() INTERNAL: Return whether the indirection policy uses transparent indirection.
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	validateContainerPolicy(IntegrityChecker checker) INTERNAL: Verify that the container policy is compatible with 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	valueFromBatchQuery(ReadQuery batchQuery, AbstractRecord row, ObjectLevelReadQuery originalQuery, CacheKey parentCacheKey) INTERNAL: Return the value to be stored in the object's attribute.
java.lang.Object	valueFromMethod(java.lang.Object object, AbstractRecord row, AbstractSession session) INTERNAL: Return the value to be stored in the object's attribute.
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	valueFromQuery(ReadQuery query, AbstractRecord row, java.lang.Object object, AbstractSession session) INTERNAL: A combination of valueFromQuery and valueFromRow(object).
java.lang.Object	valueFromRow(java.lang.Object object) INTERNAL: Return the value to be stored in the object's attribute.

Methods inherited from class org.eclipse.persistence.internal.indirection.IndirectionPolicy

clone, getMapping, initialize, isWeavedObjectBasicIndirectionPolicy, reset, setMapping, setRealAttributeValueInObject, usesIndirection, validateDeclaredAttributeTypeForCollection, validateGetMethodReturnTypeForCollection, validateSetMethodParameterTypeForCollection

Methods inherited from class java.lang.Object

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

Constructor Detail

TransparentIndirectionPolicy

public TransparentIndirectionPolicy()

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

buildIndirectObject

public java.lang.Object buildIndirectObject(ValueHolderInterface valueHolder)

INTERNAL: This method can be used when an Indirection Object is required to be built from a provided ValueHolderInterface object. This may be used for custom value holder types. Certain policies like the TransparentIndirectionPolicy may wrap the valueholder in another object.

Specified by:

buildIndirectObject in class IndirectionPolicy

cloneAttribute

public java.lang.Object cloneAttribute(java.lang.Object attributeValue,
                                       java.lang.Object original,
                                       CacheKey cacheKey,
                                       java.lang.Object clone,
                                       java.lang.Integer refreshCascade,
                                       AbstractSession cloningSession,
                                       boolean buildDirectlyFromRow)

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.lang.Object 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. OneToOneMappings should not be using transparent direction.

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

fixObjectReferences

public void fixObjectReferences(java.lang.Object object,
                                java.util.Map objectDescriptors,
                                java.util.Map processedObjects,
                                ObjectLevelReadQuery query,
                                DistributedSession session)

INTERNAL: An object has been serialized from the server to the client. Replace the transient attributes of the remote value holders with client-side objects.

Specified by:

fixObjectReferences 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.

Specified by:

getOriginalIndirectionObject in class IndirectionPolicy

getOriginalIndirectionObjectForMerge

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

INTERNAL: Return the original indirection object for a unit of work indirection object.

Overrides:

getOriginalIndirectionObjectForMerge in class IndirectionPolicy

getOriginalValueHolder

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

INTERNAL: Return the original valueHolder object. Access to the underlying valueholder may be required when serializing the valueholder or converting the valueHolder to another type.

Specified by:

getOriginalValueHolder 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

instantiateObject

public void instantiateObject(java.lang.Object object,
                              java.lang.Object attribute)

INTERNAL: Trigger the instantiation of the value.

Overrides:

instantiateObject in class IndirectionPolicy

isAttributeValueFullyBuilt

public boolean isAttributeValueFullyBuilt(java.lang.Object attributeValue)

INTERNAL: The method validateAttributeOfInstantiatedObject(Object attributeValue) fixes the value of the attributeValue in cases where it is null and indirection requires that it contain some specific data structure. Return whether this will happen. This method is used to help determine if indirection has been triggered

Overrides:

isAttributeValueFullyBuilt in class IndirectionPolicy

Parameters:

attributeValue -

Returns:

See Also:

validateAttributeOfInstantiatedObject(Object attributeValue)

getUseLazyInstantiation

public java.lang.Boolean getUseLazyInstantiation()

getValueFromRemoteValueHolder

public java.lang.Object getValueFromRemoteValueHolder(RemoteValueHolder remoteValueHolder)

INTERNAL: Extract and return the appropriate value from the specified remote value holder.

Specified by:

getValueFromRemoteValueHolder 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. If the Target has yet to be instantiated then we need to instantiate the target to ensure that the backup clone is instantiated for comparison.

Overrides:

setRealAttributeValueInObject in class IndirectionPolicy

setSourceObject

public void setSourceObject(java.lang.Object sourceObject,
                            java.lang.Object attributeValue)

INTERNAL: set the source object into QueryBasedValueHolder.

Overrides:

setSourceObject in class IndirectionPolicy

setUseLazyInstantiation

public void setUseLazyInstantiation(java.lang.Boolean useLazyInstantiation)

ADVANCED: IndirectList and IndirectSet can be configured not to instantiate the list from the database when you add and remove from them. IndirectList defaults to this behavior. When Set to true, the collection associated with this TransparentIndirection will be setup so as not to instantiate for adds and removes. The weakness of this setting for an IndirectSet is that when the set is not instantiated, if a duplicate element is added, it will not be detected until commit time.

Overrides:

setUseLazyInstantiation in class IndirectionPolicy

shouldUseLazyInstantiation

public java.lang.Boolean shouldUseLazyInstantiation()

ADVANCED: IndirectList and IndirectSet can be configured not to instantiate the list from the database when you add and remove from them. IndirectList defaults to this behavior. When Set to true, the collection associated with this TransparentIndirection will be setup so as not to instantiate for adds and removes. The weakness of this setting for an IndirectSet is that when the set is not instantiated, if a duplicate element is added, it will not be detected until commit time.

Overrides:

shouldUseLazyInstantiation 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

mergeRemoteValueHolder

public void mergeRemoteValueHolder(java.lang.Object clientSideDomainObject,
                                   java.lang.Object serverSideDomainObject,
                                   MergeManager mergeManager)

INTERNAL Replace the client value holder with the server value holder, after copying some of the settings from the client value holder.

Specified by:

mergeRemoteValueHolder 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. OneToOneMappings should not be using transparent direction.

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

objectIsEasilyInstantiated

public boolean objectIsEasilyInstantiated(java.lang.Object object)

INTERNAL: Return whether the specified object can be instantiated without database access.

Specified by:

objectIsEasilyInstantiated in class IndirectionPolicy

objectIsInstantiatedOrChanged

public boolean objectIsInstantiatedOrChanged(java.lang.Object object)

INTERNAL: Return whether the specified object is instantiated, or if it has changes.

Overrides:

objectIsInstantiatedOrChanged in class IndirectionPolicy

setDefaultContainerSize

public static void setDefaultContainerSize(int defaultSize)

ADVANCED: Set the size to of container to create. Default to using default constructor.

usesTransparentIndirection

public boolean usesTransparentIndirection()

INTERNAL: Return whether the indirection policy uses transparent indirection.

Overrides:

usesTransparentIndirection in class IndirectionPolicy

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 at least a subclass or implementor of the container type. If the value is null return a new indirection object to be used for the attribute.

Overrides:

validateAttributeOfInstantiatedObject in class IndirectionPolicy

validateContainerPolicy

public void validateContainerPolicy(IntegrityChecker checker)
                             throws DescriptorException

INTERNAL: Verify that the container policy is compatible with the indirection policy. If it is incorrect, add an exception to the integrity checker.

Overrides:

validateContainerPolicy in class IndirectionPolicy

Throws:

DescriptorException

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 compatible with the one specified by the ContainerPolicy.

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 attribute type MUST be compatible with the one specified by the ContainerPolicy.

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 attribute type MUST be compatible with the one specified by the ContainerPolicy.

Overrides:

validateSetMethodParameterType in class IndirectionPolicy

Throws:

DescriptorException

valueFromBatchQuery

public java.lang.Object valueFromBatchQuery(ReadQuery batchQuery,
                                            AbstractRecord row,
                                            ObjectLevelReadQuery originalQuery,
                                            CacheKey parentCacheKey)

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

Specified by:

valueFromBatchQuery in class IndirectionPolicy

valueFromMethod

public java.lang.Object valueFromMethod(java.lang.Object object,
                                        AbstractRecord row,
                                        AbstractSession session)

INTERNAL: Return the value to be stored in the object's attribute. This value is determined by invoking the appropriate method on the object and passing it the row and session. TransformationMappings should not be using transparent direction.

Specified by:

valueFromMethod in class IndirectionPolicy

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 an IndirectContainer for later invocation.

Specified by:

valueFromQuery in class IndirectionPolicy

valueFromQuery

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

INTERNAL: A combination of valueFromQuery and valueFromRow(object). Sometimes the attribute is known (joining) but we still need to hang on to the query (pessimistic locking).

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 allows wrapping of the real value, none is required for transparent.

Specified by:

valueFromRow in class IndirectionPolicy