Module org.eclipse.persistence.core
Package org.eclipse.persistence.internal.indirection

Class BasicIndirectionPolicy

java.lang.Object
org.eclipse.persistence.internal.indirection.IndirectionPolicy
org.eclipse.persistence.internal.indirection.BasicIndirectionPolicy
All Implemented Interfaces:
Serializable, Cloneable
Direct Known Subclasses:
ContainerIndirectionPolicy, ProxyIndirectionPolicy, WeavedObjectBasicIndirectionPolicy
public class BasicIndirectionPolicy extends IndirectionPolicy

Purpose

: BasicIndirectionPolicy implements the behavior necessary for a a org.eclipse.persistence.mappings.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
See Also:

  • Constructor Details

    • BasicIndirectionPolicy

      public BasicIndirectionPolicy()
      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

    • 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)
      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 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.
      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

    • getOriginalIndirectionObject

      public Object getOriginalIndirectionObject(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

    • 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

    • reset

      public void reset(Object target)
      Reset the wrapper used to store the value.
      Overrides:
      reset 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

    • 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

    • 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:

    • 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. In this case, return an empty ValueHolder.
      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

    • setRealAttributeValueInObject

      public void setRealAttributeValueInObject(Object target, 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

    • setSourceObject

      public void setSourceObject(Object sourceObject, Object attributeValue)
      INTERNAL: set the source object into QueryBasedValueHolder. Used only by transparent indirection.
      Overrides:
      setSourceObject in class IndirectionPolicy

    • typeIsValid

      protected boolean typeIsValid(Class<?> attributeType)
      INTERNAL: Return whether the type is appropriate for the indirection policy. In this case, the attribute type MUST be ValueHolderInterface.

    • 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 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(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(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(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

    • 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 a ValueHolder 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. In this case, wrap the row in a ValueHolder for later use.
      Specified by:
      valueFromMethod in class IndirectionPolicy

    • valueFromQuery

      public Object valueFromQuery(ReadQuery query, AbstractRecord row, Object sourceObject, 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

    • 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 a ValueHolder for later invocation.
      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 value is determined by the row. In this case, simply wrap the object in a ValueHolder.
      Specified by:
      valueFromRow in class IndirectionPolicy