oracle.toplink.essentials.internal.indirection

Class TransparentIndirectionPolicy

java.lang.Object

oracle.toplink.essentials.internal.indirection.IndirectionPolicy

oracle.toplink.essentials.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

Field Summary

Fields

Modifier and Type	Field and Description
protected static java.lang.Integer	defaultContainerSize

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

mapping

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.
protected java.lang.Object	buildBackupClone(IndirectContainer container) INTERNAL: Return a backup clone of a clone container that has not been read from the database yet.
protected IndirectContainer	buildIndirectContainer() Construct and return an instance of the specified indirect container class.
protected java.lang.Object	buildIndirectContainer(ValueHolderInterface valueHolder) Return a new IndirectContainer with the specified value holder.
java.lang.Object	cloneAttribute(java.lang.Object attributeValue, java.lang.Object original, java.lang.Object clone, UnitOfWorkImpl unitOfWork, boolean buildDirectlyFromRow) Return a clone of the attribute.
protected boolean	containerPolicyIsValid() INTERNAL: Return whether the container policy is valid for the indirection policy.
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.
protected java.lang.Class	getContainerClass() INTERNAL: Return the container class for the mapping.
protected ContainerPolicy	getContainerPolicy() INTERNAL: Return the container policy for the mapping.
protected static int	getDefaultContainerSize() INTERNAL: Return the the size to of container to create.
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.
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.
protected boolean	typeIsValid(java.lang.Class declaredType) INTERNAL: Return whether the type is appropriate for the indirection policy.
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.
protected java.lang.String	validTypeName() INTERNAL: Return the type that is appropriate for the indirection policy.
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 oracle.toplink.essentials.internal.indirection.IndirectionPolicy

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

Methods inherited from class java.lang.Object

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

Field Detail

defaultContainerSize

protected static java.lang.Integer defaultContainerSize

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

buildBackupClone

protected java.lang.Object buildBackupClone(IndirectContainer container)

INTERNAL: Return a backup clone of a clone container that has not been read from the database yet. This is used by the indirection policy to hook together a UOW clone with its backup clone - only when the clone (the working copy returned to the user) instantiates its contents from the database will these contents be copied to the backup clone.

buildIndirectContainer

protected IndirectContainer buildIndirectContainer()

Construct and return an instance of the specified indirect container class.

buildIndirectContainer

protected java.lang.Object buildIndirectContainer(ValueHolderInterface valueHolder)

Return a new IndirectContainer with the specified value holder.

cloneAttribute

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

containerPolicyIsValid

protected boolean containerPolicyIsValid()

INTERNAL: Return whether the container policy is valid for the indirection policy. In this case, the container policy MUST be configured for an IndirectContainer.

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. 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

getContainerClass

protected java.lang.Class getContainerClass()

INTERNAL: Return the container class for the mapping.

getContainerPolicy

protected ContainerPolicy getContainerPolicy()

INTERNAL: Return the container policy for the mapping.

getDefaultContainerSize

protected static int getDefaultContainerSize()

INTERNAL: Return the the size to of container to create. Default to using default constructor.

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

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

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

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. 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

setDefaultContainerSize

public static void setDefaultContainerSize(int defaultSize)

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

typeIsValid

protected boolean typeIsValid(java.lang.Class declaredType)

INTERNAL: Return whether the type is appropriate for the indirection policy. In this case, the attribute type MUST be compatible with the one specified by the ContainerPolicy (i.e. either the container policy class is a subclass of the declared type [jdk1.1] or the container policy class implements the declared interface [jdk1.2]).

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

validTypeName

protected java.lang.String validTypeName()

INTERNAL: Return the type that is appropriate for the indirection policy.

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.

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).

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