Package org.eclipse.rdf4j.spring.dao

Class RDF4JCRUDDao<ENTITY,INPUT,ID>

java.lang.Object

org.eclipse.rdf4j.spring.dao.RDF4JDao

org.eclipse.rdf4j.spring.dao.RDF4JCRUDDao<ENTITY,INPUT,ID>

Type Parameters:

ENTITY -

INPUT -

ID -

Direct Known Subclasses:

SimpleRDF4JCRUDDao

public abstract class RDF4JCRUDDao<ENTITY,INPUT,ID>
extends RDF4JDao

Base class for DAOs providing CRUD functionality. The class allows for entities to be represented with different classes for read (ENTITY type) vs write (INPUT type) operations. DAOs that do not require this distinction must use the same class for both parameters.

Since:

4.0.0

Author:

Florian Kleedorfer

Nested Class Summary

Nested classes/interfaces inherited from class org.eclipse.rdf4j.spring.dao.RDF4JDao

RDF4JDao.NamedSparqlSupplierFinishBuilder, RDF4JDao.NamedSparqlSupplierPreparer

Field Summary

Fields

Modifier and Type	Field	Description
static final String	KEY_PREFIX_INSERT
static final String	KEY_PREFIX_UPDATE

Constructor Summary

Constructors

Constructor	Description
RDF4JCRUDDao(RDF4JTemplate rdf4JTemplate)	Constructor to be used by implementations that use IRI for the ID type.
RDF4JCRUDDao(RDF4JTemplate rdf4JTemplate, Class<ID> idClass)	Constructor that provides the type of the ID to the base implementation.

Method Summary

Modifier and Type	Method	Description
protected IRI	convertIdToIri(ID id)	Converts the provided id to an IRI.
void	delete(ID id)	Naive implementation using RDF4JTemplate.delete(IRI).
protected void	deleteForUpdate(ID id)	When updating an entity via save(Object), its triples are removed first using this method.
protected ID	generateNewId(ID providedId)	Generates a new id for an entity.
final ENTITY	getById(ID id)	Obtains the entity with the specified id, throwing an exception if none is found.
final Optional<ENTITY>	getByIdOptional(ID id)	Obtains an optional entity with the specified id.
protected ID	getInputId(INPUT input)	Obtains the id of the input instance or null if it is new (or a partially populated composite key).
protected NamedSparqlSupplier	getInsertSparql(INPUT input)	Returns the SPARQL string used to write an instance of T to the database.
protected String	getReadQuery()	Returns the SPARQL string used to read an instance of T from the database.
protected NamedSparqlSupplier	getUpdateSparql(INPUT input)	Returns the SPARQL string used to update an instance of T in the database.
final List<ENTITY>	list()
protected ENTITY	mapSolution(BindingSet querySolution)	Map one solution of the readQuery to the type of this DAO.
protected static BindingsBuilder	newBindingsBuilder()	Returns a new BindingsBuilder for your convenience.
protected void	populateBindingsForUpdate(MutableBindings bindingsBuilder, INPUT input)	Sets the non-id bindings on for the write query such that the instance of type I is written to the database.
protected abstract void	populateIdBindings(MutableBindings bindingsBuilder, ID id)	Binds the instance id to query variable(s).
protected ENTITY	postProcessMappedSolution(ENTITY entity)	Callback invoked after mapping a solution to an entity, allowing subclasses to modify the entity before returning it to the client.
protected void	postProcessUpdate(INPUT input, Map<String,Value> bindings)	Callback invoked after a successful insert/update.
final ENTITY	save(INPUT input)	Saves the entity, loads it again and returns it.
ID	saveAndReturnId(INPUT input)
ID	saveAndReturnId(INPUT input, ID id)	Saves the entity and returns its (possibly newly generated) ID.

Methods inherited from class org.eclipse.rdf4j.spring.dao.RDF4JDao

getNamedGraphQuery, getNamedSparqlString, getNamedSparqlSupplier, getNamedTupleQuery, getNamedUpdate, getRdf4JTemplate, prepareNamedSparqlSuppliers

Methods inherited from class java.lang.Object

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

Field Details

KEY_PREFIX_INSERT

public static final String KEY_PREFIX_INSERT

See Also:

• Constant Field Values

KEY_PREFIX_UPDATE

public static final String KEY_PREFIX_UPDATE

See Also:

• Constant Field Values

Constructor Details

RDF4JCRUDDao

public RDF4JCRUDDao(RDF4JTemplate rdf4JTemplate,
 Class<ID> idClass)

Constructor that provides the type of the ID to the base implementation. This constructor has to be used if the ID is anything but IRI.

RDF4JCRUDDao

public RDF4JCRUDDao(RDF4JTemplate rdf4JTemplate)

Constructor to be used by implementations that use IRI for the ID type.

Method Details

save

public final ENTITY save(INPUT input)

Saves the entity, loads it again and returns it. If the modified entity is not required, clients should prefer saveAndReturnId(Object, Object) or saveAndReturnId(Object)

saveAndReturnId

public ID saveAndReturnId(INPUT input)

saveAndReturnId

public ID saveAndReturnId(INPUT input,
 ID id)

Saves the entity and returns its (possibly newly generated) ID.

Parameters:

input - the entity

id - the id or null for a new entity.

Returns:

the id (a newly generated one if the specified id is null, otherwise just id.

deleteForUpdate

protected void deleteForUpdate(ID id)

When updating an entity via save(Object), its triples are removed first using this method. The default implementation used RDF4JTemplate.deleteTriplesWithSubject(IRI). If more complex deletion behaviour (e.g. cascading) is needed, this method should be overriden.

convertIdToIri

protected IRI convertIdToIri(ID id)

Converts the provided id to an IRI. The default implementation only works for DAOs that use IRI ids.

Parameters:

id -

Returns:

generateNewId

protected ID generateNewId(ID providedId)

Generates a new id for an entity. The default implementation only works for IRI ids.

Parameters:

providedId -

Returns:

a new id.

list

public final List<ENTITY> list()

getById

public final ENTITY getById(ID id)

Obtains the entity with the specified id, throwing an exception if none is found.

Parameters:

id - the id

Returns:

the entity

Throws:

IncorrectResultSetSizeException - if no entity is found with the specified id

getByIdOptional

public final Optional<ENTITY> getByIdOptional(ID id)

Obtains an optional entity with the specified id.

Parameters:

id - the id

Returns:

an Optional maybe containing the entity

delete

public void delete(ID id)

Naive implementation using RDF4JTemplate.delete(IRI). DAOs that need more complex deletion behaviour (e.g. cascading) should override this method.

getReadQuery

protected String getReadQuery()

Returns the SPARQL string used to read an instance of T from the database. The base implementation will cache the query string, so implementations should not try to cache the query.

mapSolution

protected ENTITY mapSolution(BindingSet querySolution)

Map one solution of the readQuery to the type of this DAO.

postProcessMappedSolution

protected ENTITY postProcessMappedSolution(ENTITY entity)

Callback invoked after mapping a solution to an entity, allowing subclasses to modify the entity before returning it to the client.

postProcessUpdate

protected void postProcessUpdate(INPUT input,
 Map<String,Value> bindings)

Callback invoked after a successful insert/update.

getInsertSparql

protected NamedSparqlSupplier getInsertSparql(INPUT input)

Returns the SPARQL string used to write an instance of T to the database. The instance to be inserted is passed to the function so implementations can decide which query to use based on the instance.

getUpdateSparql

protected NamedSparqlSupplier getUpdateSparql(INPUT input)

Returns the SPARQL string used to update an instance of T in the database. The instance to be updated is passed to the function so implementations can decide which query to use based on the instance.

populateIdBindings

protected abstract void populateIdBindings(MutableBindings bindingsBuilder,
 ID id)

Binds the instance id to query variable(s).

populateBindingsForUpdate

protected void populateBindingsForUpdate(MutableBindings bindingsBuilder,
 INPUT input)

Sets the non-id bindings on for the write query such that the instance of type I is written to the database. ID bindings are set through populateIdBindings()

getInputId

protected ID getInputId(INPUT input)

Obtains the id of the input instance or null if it is new (or a partially populated composite key).

newBindingsBuilder

protected static BindingsBuilder newBindingsBuilder()

Returns a new BindingsBuilder for your convenience.