Module org.eclipse.persistence.core
Package 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:
Serializable, 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
See Also:

  • Field Details

    • defaultContainerSize

      protected static Integer defaultContainerSize

    • containerPolicy

      protected ContainerPolicy containerPolicy
      PERF: Cache the mappings container policy.

    • useLazyInstantiation

      protected Boolean useLazyInstantiation
      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.

  • Constructor Details

    • TransparentIndirectionPolicy

      public TransparentIndirectionPolicy()
      INTERNAL: Construct a new indirection policy.

  • Method Details

    • backupCloneAttribute

      public Object backupCloneAttribute(Object attributeValue, Object clone, Object backup, UnitOfWorkImpl unitOfWork)
      INTERNAL: Return a backup clone of the attribute.
      Overrides:
      backupCloneAttribute in class IndirectionPolicy

    • buildBackupClone

      protected 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 Object buildIndirectContainer(ValueHolderInterface valueHolder)
      Return a new IndirectContainer with the specified value holder.

    • buildIndirectObject

      public 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 Object cloneAttribute(Object attributeValue, Object original, CacheKey cacheKey, Object clone, 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.

    • 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 Object extractPrimaryKeyForReferenceObject(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(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(Object object, Map<Object,ObjectDescriptor> objectDescriptors, Map<Object,Object> 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

    • getContainerClass

      protected 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 Object getOriginalIndirectionObject(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 Object getOriginalIndirectionObjectForMerge(Object unitOfWorkIndirectionObject, AbstractSession session)
      INTERNAL: Return the original indirection object for a unit of work indirection object.
      Overrides:
      getOriginalIndirectionObjectForMerge in class IndirectionPolicy

    • getOriginalValueHolder

      public Object getOriginalValueHolder(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 Object getRealAttributeValueFromObject(Object object, 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(Object object, Object attribute)
      INTERNAL: Trigger the instantiation of the value.
      Overrides:
      instantiateObject in class IndirectionPolicy

    • isAttributeValueFullyBuilt

      public boolean isAttributeValueFullyBuilt(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
      See Also:

    • getUseLazyInstantiation

      public Boolean getUseLazyInstantiation()

    • getValueFromRemoteValueHolder

      public 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(Object target, 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(Object sourceObject, Object attributeValue)
      INTERNAL: set the source object into QueryBasedValueHolder.
      Overrides:
      setSourceObject in class IndirectionPolicy

    • setUseLazyInstantiation

      public void setUseLazyInstantiation(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 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, Object attributeValue)
      INTERNAL: Iterate over the specified attribute value.
      Overrides:
      iterateOnAttributeValue in class IndirectionPolicy

    • mergeRemoteValueHolder

      public void mergeRemoteValueHolder(Object clientSideDomainObject, 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 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(Object object)
      INTERNAL: Return whether the specified object is instantiated.
      Specified by:
      objectIsInstantiated in class IndirectionPolicy

    • objectIsEasilyInstantiated

      public boolean objectIsEasilyInstantiated(Object object)
      INTERNAL: Return whether the specified object can be instantiated without database access.
      Specified by:
      objectIsEasilyInstantiated in class IndirectionPolicy

    • objectIsInstantiatedOrChanged

      public boolean objectIsInstantiatedOrChanged(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.

    • typeIsValid

      protected boolean typeIsValid(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 Object validateAttributeOfInstantiatedObject(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(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(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(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 String validTypeName()
      INTERNAL: Return the type that is appropriate for the indirection policy.

    • valueFromBatchQuery

      public 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 Object valueFromMethod(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 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 Object valueFromQuery(ReadQuery query, AbstractRecord row, 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 Object valueFromRow(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