org.springframework.data.neo4j.core
Interface TypeRepresentationStrategy<S extends org.neo4j.graphdb.PropertyContainer,T extends GraphBacked<S>>

All Known Subinterfaces:

NodeTypeRepresentationStrategy, RelationshipTypeRepresentationStrategy

All Known Implementing Classes:

IndexingNodeTypeRepresentationStrategy, IndexingRelationshipTypeRepresentationStrategy, NoopNodeTypeRepresentationStrategy, NoopRelationshipTypeRepresentationStrategy, SubReferenceNodeTypeRepresentationStrategy

public interface TypeRepresentationStrategy<S extends org.neo4j.graphdb.PropertyContainer,T extends GraphBacked<S>>

Strategy to handle representation of java types in the graph. Possible implementation are type/class nodes (forming an inheritance chain) that is linked to from the instance and keeps a count of the instances. Another approach could use indexing and a type property on the instance fields. Contains a callback on entity creation that can setup the type representation. The finder methods are delegated to for the appropriate calls for the strategy set for the datastore.

Since:

13.09.2010

Author:

Michael Hunger

Method Summary

long	count(Class<? extends T> entityClass)
<U extends T> U	createEntity(S state) Instantiate the entity given its state.
<U extends T> U	createEntity(S state, Class<U> type) Instantiate the entity given its state.
<U extends T> org.neo4j.helpers.collection.ClosableIterable<U>	findAll(Class<U> clazz)
<U extends T> Class<U>	getJavaType(S state)
void	postEntityCreation(S state, Class<? extends T> type) Callback for setting up and/or storing type information after creation.
void	preEntityRemoval(S state) Callback for cleaning up type information before removal.
<U extends T> U	projectEntity(S state, Class<U> type) Instantiate the entity of the given type, with the given state as backing state.

Method Detail

postEntityCreation

void postEntityCreation(S state,
                        Class<? extends T> type)

Callback for setting up and/or storing type information after creation.

Parameters:

state - Backing state of entity being created

type - Type of entity being created

findAll

<U extends T> org.neo4j.helpers.collection.ClosableIterable<U> findAll(Class<U> clazz)

Parameters:

clazz - Type whose instances should be iterated over

Returns:

lazy Iterable over all instances of the given type

count

long count(Class<? extends T> entityClass)

Parameters:

entityClass -

Returns:

number of instances of this class contained in the graph

getJavaType

<U extends T> Class<U> getJavaType(S state)

Parameters:

state -

Returns:

java type that of the node entity of this node

preEntityRemoval

void preEntityRemoval(S state)

Callback for cleaning up type information before removal. If state does not have any state associated, doesn't do anything.

Parameters:

state - Backing state of entity being removed

createEntity

<U extends T> U createEntity(S state)
                         throws IllegalStateException

Instantiate the entity given its state. The type of the entity is inferred by the strategy from the state.

Type Parameters:

U - Helper parameter for castless use

Parameters:

state - Backing state of entity to be instantiated

Returns:

Entity instance

Throws:

IllegalStateException - If the strategy is unable to infer any type from the state

createEntity

<U extends T> U createEntity(S state,
                             Class<U> type)
                         throws IllegalStateException,
                                IllegalArgumentException

Instantiate the entity given its state. The type of the desired entity is also specified. If the type is not compatible with what the strategy can infer from the state, IllegalArgumentException is thrown.

Parameters:

state - Backing state of entity to be instantiated

type - Type of entity to be instantiated

Returns:

Entity instance

Throws:

IllegalStateException - If the strategy is unable to infer any type from the state

IllegalArgumentException - If the specified type does not match the inferred type

projectEntity

<U extends T> U projectEntity(S state,
                              Class<U> type)

Instantiate the entity of the given type, with the given state as backing state. No checking is done by the strategy.

Parameters:

state - Backing state of entity to be instantiated

type - Type of entity to be instantiated

Returns:

Entity instance.