Package org.eclipse.persistence.internal.indirection

Class ContainerIndirectionPolicy

  • All Implemented Interfaces:
    Serializable, Cloneable
    public class ContainerIndirectionPolicy
extends BasicIndirectionPolicy
    Purpose: Provide ability for developers to wrap ValueHolders (Basic Indirection)

    Responsibilities:

    • Wrap & un-wrap a ValueHolder within an IndirectContainer
    • Reflectively instantiate the containers as required
    Since:
    2.5.0.5
    Author:
    Doug Clarke (TOP)
    See Also:
    IndirectContainer, Serialized Form

    • Constructor Detail

      • ContainerIndirectionPolicy

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

    • Method Detail

      • 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.
        Overrides:
        buildIndirectObject in class BasicIndirectionPolicy

      • 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.
        Overrides:
        cloneAttribute in class BasicIndirectionPolicy
        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.

      • 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.
        Overrides:
        extractReferenceRow in class BasicIndirectionPolicy

      • getContainerClass

        public Class getContainerClass()
        Returns the Container class which implements IndirectContainer.

      • getContainerClassName

        public String getContainerClassName()
        INTERNAL: Used by MW.

      • getContainerConstructor

        protected Constructor getContainerConstructor()
        Returns:
        java.lang.reflect.Constructor

      • initialize

        public void initialize()
        INTERNAL: Ensure the container class implements IndirectContainer and that it has a constructor which can be used.
        Overrides:
        initialize 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 BasicIndirectionPolicy
        Parameters:
        attributeValue -
        Returns:
        See Also:
        validateAttributeOfInstantiatedObject(java.lang.Object)

      • 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.
        Overrides:
        nullValueFromRow in class BasicIndirectionPolicy

      • setContainerClass

        public void setContainerClass​(Class containerClass)
        Sets the Container class which implements IndirectContainer

      • setContainterClassName

        public void setContainterClassName​(String containerClassName)
        Set the container classname for the MW

      • 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 BasicIndirectionPolicy

      • typeIsValid

        protected boolean typeIsValid​(Class attributeType)
        INTERNAL: Return whether the type is appropriate for the indirection policy. In this case, the type must either be assignable from IndirectContainer or allow the conatinerClass to be assigned to it.
        Overrides:
        typeIsValid in class BasicIndirectionPolicy

      • 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.
        Overrides:
        validateAttributeOfInstantiatedObject in class BasicIndirectionPolicy

      • 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.
        Overrides:
        valueFromMethod in class BasicIndirectionPolicy

      • 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.
        Overrides:
        valueFromRow in class BasicIndirectionPolicy