org.hibernate.loader.plan.build.internal

Class AbstractEntityGraphVisitationStrategy

java.lang.Object

org.hibernate.loader.plan.build.internal.AbstractLoadPlanBuildingAssociationVisitationStrategy

org.hibernate.loader.plan.build.internal.AbstractEntityGraphVisitationStrategy

All Implemented Interfaces:

LoadPlanBuildingAssociationVisitationStrategy, LoadPlanBuildingContext, AssociationVisitationStrategy

Direct Known Subclasses:

FetchGraphLoadPlanBuildingStrategy, LoadGraphLoadPlanBuildingStrategy

public abstract class AbstractEntityGraphVisitationStrategy
extends AbstractLoadPlanBuildingAssociationVisitationStrategy

Abstract strategy of building loadplan based on entity graph. The problem we're resolving here is, we have TWO trees to walk (only entity loading here):

entity metadata and its associations
entity graph and attribute nodes

And most time, the entity graph tree is partial of entity metadata tree. So, the idea here is, we walk the entity metadata tree, just as how we build the static loadplan from mappings, and we try to match the node to entity graph ( and subgraph ), if there is a match, then the attribute is fetched, it is not, then depends on which property is used to apply this entity graph.

Author:

Strong Liu , Brett Meyer

Nested Class Summary

Nested classes/interfaces inherited from class org.hibernate.loader.plan.build.internal.AbstractLoadPlanBuildingAssociationVisitationStrategy

AbstractLoadPlanBuildingAssociationVisitationStrategy.PropertyPathStack

Field Summary

Fields

Modifier and Type	Field and Description
protected static FetchStrategy	DEFAULT_EAGER The JPA 2.1 SPEC's Entity Graph only defines _WHEN_ to load an attribute, it doesn't define _HOW_ to load it So I'm here just making an assumption that when it is EAGER, then we use JOIN, and when it is LAZY, then we use SELECT.
protected static FetchStrategy	DEFAULT_LAZY
protected LoadQueryInfluencers	loadQueryInfluencers

Fields inherited from class org.hibernate.loader.plan.build.internal.AbstractLoadPlanBuildingAssociationVisitationStrategy

currentPropertyPath

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractEntityGraphVisitationStrategy(SessionFactoryImplementor sessionFactory, LoadQueryInfluencers loadQueryInfluencers, LockMode lockMode)

Method Summary

Modifier and Type	Method and Description
protected void	addRootReturn(Return rootReturn)
protected FetchStrategy	adjustJoinFetchIfNeeded(AssociationAttributeDefinition attributeDefinition, FetchStrategy fetchStrategy)
protected Map<String,AttributeNodeImplementor>	buildAttributeNodeMap() Build "name" -- "attribute node" map from the current entity graph we're visiting.
LoadPlan	buildLoadPlan() After visitation is done, build the load plan.
protected FetchStrategy	determineFetchStrategy(AssociationAttributeDefinition attributeDefinition)
void	finish() Notification we are finished visitation.
void	finishingAttribute(AttributeDefinition attributeDefinition) Notification that we are finishing walking an attribute.
void	finishingCollectionElements(CollectionElementDefinition elementDefinition) Notification that we are finishing walking the elements of a collection (List/Map).
void	finishingCollectionIndex(CollectionIndexDefinition indexDefinition) Notification that we are finishing walking the index of a collection (List/Map).
void	finishingEntity(EntityDefinition entityDefinition) Notification we are finishing walking an entity.
void	foundCircularAssociation(AssociationAttributeDefinition attributeDefinition)
protected abstract GraphNodeImplementor	getRootEntityGraph()
protected abstract FetchStrategy	resolveImplicitFetchStrategyFromEntityGraph(AssociationAttributeDefinition attributeDefinition)
void	start() Notification we are preparing to start visitation.
boolean	startingAttribute(AttributeDefinition attributeDefinition) I'm using the NULL-OBJECT pattern here.
void	startingCollectionElements(CollectionElementDefinition elementDefinition) Notification that we are starting to look at the element definition for the collection.
void	startingCollectionIndex(CollectionIndexDefinition indexDefinition) Notification that we are starting to walk the index of a collection (List/Map).
void	startingEntity(EntityDefinition entityDefinition) Notification we are starting to walk an entity.
protected boolean	supportsRootCollectionReturns()

Methods inherited from class org.hibernate.loader.plan.build.internal.AbstractLoadPlanBuildingAssociationVisitationStrategy

associationKeyRegistered, currentDepth, currentSource, finishingCollection, finishingComposite, finishingEntityIdentifier, foundAny, getQuerySpaces, getSessionFactory, handleAssociationAttribute, handleCompositeAttribute, isDuplicateAssociationKey, isTooManyCollections, registeredFetchSource, sessionFactory, startingCollection, startingComposite, startingEntityIdentifier, supportsRootEntityReturns

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_EAGER

protected static final FetchStrategy DEFAULT_EAGER

The JPA 2.1 SPEC's Entity Graph only defines _WHEN_ to load an attribute, it doesn't define _HOW_ to load it So I'm here just making an assumption that when it is EAGER, then we use JOIN, and when it is LAZY, then we use SELECT. NOTE: this may be changed in the near further, though ATM I have no idea how this will be changed to :) -- stliu

DEFAULT_LAZY

protected static final FetchStrategy DEFAULT_LAZY

loadQueryInfluencers

protected final LoadQueryInfluencers loadQueryInfluencers

Constructor Detail

AbstractEntityGraphVisitationStrategy

protected AbstractEntityGraphVisitationStrategy(SessionFactoryImplementor sessionFactory,
                                                LoadQueryInfluencers loadQueryInfluencers,
                                                LockMode lockMode)

Method Detail

start

public void start()

Description copied from interface: AssociationVisitationStrategy

Notification we are preparing to start visitation.

Specified by:

start in interface AssociationVisitationStrategy

Overrides:

start in class AbstractLoadPlanBuildingAssociationVisitationStrategy

finish

public void finish()

Description copied from interface: AssociationVisitationStrategy

Notification we are finished visitation.

Specified by:

finish in interface AssociationVisitationStrategy

Overrides:

finish in class AbstractLoadPlanBuildingAssociationVisitationStrategy

startingEntity

public void startingEntity(EntityDefinition entityDefinition)

Description copied from interface: AssociationVisitationStrategy

Notification we are starting to walk an entity.

Specified by:

startingEntity in interface AssociationVisitationStrategy

Overrides:

startingEntity in class AbstractLoadPlanBuildingAssociationVisitationStrategy

Parameters:

entityDefinition - The entity we are preparing to walk

buildAttributeNodeMap

protected Map<String,AttributeNodeImplementor> buildAttributeNodeMap()

Build "name" -- "attribute node" map from the current entity graph we're visiting.

finishingEntity

public void finishingEntity(EntityDefinition entityDefinition)

Description copied from interface: AssociationVisitationStrategy

Notification we are finishing walking an entity.

Specified by:

finishingEntity in interface AssociationVisitationStrategy

Overrides:

finishingEntity in class AbstractLoadPlanBuildingAssociationVisitationStrategy

Parameters:

entityDefinition - The entity we are finishing walking.

startingAttribute

public boolean startingAttribute(AttributeDefinition attributeDefinition)

I'm using the NULL-OBJECT pattern here. For attributes that don't exist in the EntityGraph, a predefined NULL-ATTRIBUTE-NODE is pushed to the stack. And for a nonexistent subgraph, a predefined NULL-SUBGRAPH is pushed to the stack. So, whenever we start visiting an attribute, there will be an attribute node pushed to the attribute stack, and a subgraph node pushed to the graph stack. when we finish visiting an attribute, these two will be popped from each stack.

Specified by:

startingAttribute in interface AssociationVisitationStrategy

Overrides:

startingAttribute in class AbstractLoadPlanBuildingAssociationVisitationStrategy

Parameters:

attributeDefinition - The attribute we are preparing to walk.

Returns:

true if the walking should continue; false if walking should stop.

finishingAttribute

public void finishingAttribute(AttributeDefinition attributeDefinition)

Description copied from interface: AssociationVisitationStrategy

Notification that we are finishing walking an attribute.

Specified by:

finishingAttribute in interface AssociationVisitationStrategy

Overrides:

finishingAttribute in class AbstractLoadPlanBuildingAssociationVisitationStrategy

Parameters:

attributeDefinition - The attribute we are done walking

startingCollectionElements

public void startingCollectionElements(CollectionElementDefinition elementDefinition)

Description copied from interface: AssociationVisitationStrategy

Notification that we are starting to look at the element definition for the collection. If the collection elements are entities this will be followed up by a call to AssociationVisitationStrategy.startingEntity(org.hibernate.persister.walking.spi.EntityDefinition)

Specified by:

startingCollectionElements in interface AssociationVisitationStrategy

Overrides:

startingCollectionElements in class AbstractLoadPlanBuildingAssociationVisitationStrategy

Parameters:

elementDefinition - The collection element we are preparing to walk..

finishingCollectionElements

public void finishingCollectionElements(CollectionElementDefinition elementDefinition)

Description copied from interface: AssociationVisitationStrategy

Notification that we are finishing walking the elements of a collection (List/Map).

Specified by:

finishingCollectionElements in interface AssociationVisitationStrategy

Overrides:

finishingCollectionElements in class AbstractLoadPlanBuildingAssociationVisitationStrategy

Parameters:

elementDefinition - The collection element we are finishing

startingCollectionIndex

public void startingCollectionIndex(CollectionIndexDefinition indexDefinition)

Description copied from interface: AssociationVisitationStrategy

Notification that we are starting to walk the index of a collection (List/Map). In the case of a Map, if the indices (the keys) are entities this will be followed up by a call to AssociationVisitationStrategy.startingEntity(org.hibernate.persister.walking.spi.EntityDefinition)

Specified by:

startingCollectionIndex in interface AssociationVisitationStrategy

Overrides:

startingCollectionIndex in class AbstractLoadPlanBuildingAssociationVisitationStrategy

Parameters:

indexDefinition - The collection index we are preparing to walk.

finishingCollectionIndex

public void finishingCollectionIndex(CollectionIndexDefinition indexDefinition)

Description copied from interface: AssociationVisitationStrategy

Notification that we are finishing walking the index of a collection (List/Map).

Specified by:

finishingCollectionIndex in interface AssociationVisitationStrategy

Overrides:

finishingCollectionIndex in class AbstractLoadPlanBuildingAssociationVisitationStrategy

Parameters:

indexDefinition - The collection index we are finishing

supportsRootCollectionReturns

protected boolean supportsRootCollectionReturns()

Overrides:

supportsRootCollectionReturns in class AbstractLoadPlanBuildingAssociationVisitationStrategy

addRootReturn

protected void addRootReturn(Return rootReturn)

Specified by:

addRootReturn in class AbstractLoadPlanBuildingAssociationVisitationStrategy

determineFetchStrategy

protected FetchStrategy determineFetchStrategy(AssociationAttributeDefinition attributeDefinition)

Specified by:

determineFetchStrategy in class AbstractLoadPlanBuildingAssociationVisitationStrategy

resolveImplicitFetchStrategyFromEntityGraph

protected abstract FetchStrategy resolveImplicitFetchStrategyFromEntityGraph(AssociationAttributeDefinition attributeDefinition)

adjustJoinFetchIfNeeded

protected FetchStrategy adjustJoinFetchIfNeeded(AssociationAttributeDefinition attributeDefinition,
                                                FetchStrategy fetchStrategy)

buildLoadPlan

public LoadPlan buildLoadPlan()

Description copied from interface: LoadPlanBuildingAssociationVisitationStrategy

After visitation is done, build the load plan.

Returns:

The load plan

getRootEntityGraph

protected abstract GraphNodeImplementor getRootEntityGraph()

foundCircularAssociation

public void foundCircularAssociation(AssociationAttributeDefinition attributeDefinition)

Specified by:

foundCircularAssociation in interface AssociationVisitationStrategy

Overrides:

foundCircularAssociation in class AbstractLoadPlanBuildingAssociationVisitationStrategy