org.neo4j.ogm.context

Class MappingContext

java.lang.Object

org.neo4j.ogm.context.MappingContext

public class MappingContext
extends Object

The MappingContext maintains a map of all the objects created during the hydration of an object map (domain hierarchy). The MappingContext lifetime is concurrent with a session lifetime.

Author:

Vince Bickers, Luanne Misquitta, Mark Angrish

Constructor Summary

Constructors

Constructor and Description
MappingContext(MetaData metaData)

Method Summary

Modifier and Type	Method and Description
Object	addNodeEntity(Object entity) Adds an entity to the MappingContext.
Object	addNodeEntity(Object entity, Long id) Adds an entity to the MappingContext.
void	addRelationship(MappedRelationship relationship)
Object	addRelationshipEntity(Object relationshipEntity, Long id)
void	clear()
boolean	containsRelationship(MappedRelationship relationship)
boolean	detachNodeEntity(Long id)
boolean	detachRelationshipEntity(Long id)
Object	getNodeEntity(Long graphId) Gets a node entity from the MappingContext by its graph id.
Object	getNodeEntityById(ClassInfo classInfo, Object id) Get a node entity from the MappingContext by its primary id
Object	getRelationshipEntity(Long relationshipId)
Object	getRelationshipEntityById(ClassInfo classInfo, Object id) Get a relationship entity from MappingContext by primary id
Set<MappedRelationship>	getRelationships()
Map<Long,Object>	getSnapshotOfRelationshipEntityRegister()
boolean	isDirty(Object entity) Check if the entity has been modified by comparing its current state to the state it had when registered.
Long	nativeId(Object entity)
Set<Object>	neighbours(Object entity) Get related objects of an entity / relationship.
void	removeType(Class<?> type) purges all information about objects of the supplied type from the mapping context.
void	replaceNodeEntity(Object entity, Long identity)
void	replaceRelationshipEntity(Object entity, Long id)
void	reset(Object entity) purges all information about this object from the mapping context and also sets its id to null.

Methods inherited from class java.lang.Object

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

Constructor Detail

MappingContext

public MappingContext(MetaData metaData)

Method Detail

getNodeEntity

public Object getNodeEntity(Long graphId)

Gets a node entity from the MappingContext by its graph id. NOTE: to get entity by field with @Id use getNodeEntityById(ClassInfo, Object) - you also need to check if such id exists and is of correct type

Parameters:

graphId - The graph id to look for.

Returns:

The entity or null if not found.

getNodeEntityById

public Object getNodeEntityById(ClassInfo classInfo,
                                Object id)

Get a node entity from the MappingContext by its primary id

Parameters:

classInfo - class info of the entity (this must be provided because id itself is not unique)

id - primary id of the entity

Returns:

the entity or null if not found

addNodeEntity

public Object addNodeEntity(Object entity)

Adds an entity to the MappingContext.

Parameters:

entity - The object to add.

Returns:

The object added, never null.

addNodeEntity

public Object addNodeEntity(Object entity,
                            Long id)

Adds an entity to the MappingContext.

Parameters:

entity - The object to add.

id -

Returns:

The object added, never null.

replaceNodeEntity

public void replaceNodeEntity(Object entity,
                              Long identity)

replaceRelationshipEntity

public void replaceRelationshipEntity(Object entity,
                                      Long id)

isDirty

public boolean isDirty(Object entity)

Check if the entity has been modified by comparing its current state to the state it had when registered. TBD : describe how the hash is computed. Not sure if it is a real deep hash.

Parameters:

entity - The entity to check

Returns:

true if the entity was changed, false otherwise.

containsRelationship

public boolean containsRelationship(MappedRelationship relationship)

getRelationships

public Set<MappedRelationship> getRelationships()

addRelationship

public void addRelationship(MappedRelationship relationship)

clear

public void clear()

getSnapshotOfRelationshipEntityRegister

public Map<Long,Object> getSnapshotOfRelationshipEntityRegister()

getRelationshipEntity

public Object getRelationshipEntity(Long relationshipId)

getRelationshipEntityById

public Object getRelationshipEntityById(ClassInfo classInfo,
                                        Object id)

Get a relationship entity from MappingContext by primary id

Parameters:

classInfo - classInfo of the relationship entity (it is needed to because primary id may not be unique across all relationship types)

id - primary id of the entity

Returns:

relationship entity

addRelationshipEntity

public Object addRelationshipEntity(Object relationshipEntity,
                                    Long id)

removeType

public void removeType(Class<?> type)

purges all information about objects of the supplied type from the mapping context. If the type is an interface, purges all implementing classes in the interface hierarchy

Parameters:

type - the type whose object references and relationship mappings we want to purge

detachNodeEntity

public boolean detachNodeEntity(Long id)

detachRelationshipEntity

public boolean detachRelationshipEntity(Long id)

reset

public void reset(Object entity)

purges all information about this object from the mapping context and also sets its id to null. Should be called for new objects that have had their id assigned as part of a long-running transaction, if that transaction is subsequently rolled back.

Parameters:

entity - the instance whose references and relationship mappings we want to reset

neighbours

public Set<Object> neighbours(Object entity)

Get related objects of an entity / relationship. Used in deletion scenarios.

Parameters:

entity - The entity to look neighbours for.

Returns:

If entity is a relationship, end and start nodes. If entity is a node, the relations pointing to it.

nativeId

public Long nativeId(Object entity)