Package org.apache.jena.sparql.core

Class DatasetGraphBase

java.lang.Object

org.apache.jena.sparql.core.DatasetGraphBase

All Implemented Interfaces:

org.apache.jena.atlas.lib.Closeable, DatasetGraph, Transactional

Direct Known Subclasses:

DatasetGraphBaseFind, DatasetGraphQuads

public abstract class DatasetGraphBase
extends java.lang.Object
implements DatasetGraph

DatasetGraph framework : readonly dataset need only provide find(g,s,p,o), getGraph() and getDefaultGraph() although it may wish to override other operations and do better.

Implementations include:

• DatasetGraphBase that adds an implementation of find based on default / named graphs.
• DatasetGraphInMemory provides full transactions for an in-memory DatasetGraph.
• DatasetGraphTriplesQuads that adds mutating quad operations.
• DatasetGraphMap provides for operations working over a collection of in-memory graphs.
• DatasetGraphMapLink provides for operations working over a collection of graphs provided by the application.
• DatasetGraphCollection that provides for operations working over a collection of graphs.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.jena.sparql.core.Transactional

Transactional.Promote

Method Summary

Modifier and Type	Method	Description
void	add(Node g, Node s, Node p, Node o)	Add a quad
void	add(Quad quad)	Add a quad
abstract void	addGraph(Node graphName, Graph graph)	Add the given graph to the dataset.
void	clear()	Remove everything - remove all named graphs, clear the default graph
void	close()	Close the dataset
boolean	contains(Node g, Node s, Node p, Node o)	Test whether the dataset (including default graph) contains a quad - may include wildcards, Node.ANY or null
boolean	contains(Quad quad)	Test whether the dataset contains a quad (including default graph)- may include wildcards, Node.ANY or null
boolean	containsGraph(Node graphNode)	Does the DatasetGraph contain a specific named graph? Whether a dataset contains a graph if there are no triples is not defined - see the specific implementation.
void	delete(Node g, Node s, Node p, Node o)	Delete a quad
void	delete(Quad quad)	Delete a quad
void	deleteAny(Node g, Node s, Node p, Node o)	Delete any quads matching the pattern
static void	deleteAny(DatasetGraph dsg, Node g, Node s, Node p, Node o)
java.util.Iterator<Quad>	find()	Iterate over all quads in the dataset graph
java.util.Iterator<Quad>	find(Quad quad)	Find matching quads in the dataset - may include wildcards, Node.ANY or null
Context	getContext()	Get the context associated with this object - may be null
abstract Graph	getDefaultGraph()	Get the default graph as a Jena Graph
abstract Graph	getGraph(Node graphNode)	Get the graph named by graphNode : returns null when there is no such graph.
Lock	getLock()	Return a lock for the dataset to help with concurrency control
Graph	getUnionGraph()	Return a Graph that is the union of all named graphs in this dataset.
boolean	isEmpty()	Test whether the dataset is empty
abstract void	removeGraph(Node graphName)	Remove all data associated with the named graph.
void	setDefaultGraph(Graph g)	Set the default graph.
long	size()	Get the size (number of named graphs) - may be -1 for unknown
java.lang.String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.jena.sparql.core.DatasetGraph

addAll, find, findNG, listGraphNodes, prefixes, supportsTransactionAbort, supportsTransactions

Methods inherited from interface org.apache.jena.sparql.core.Transactional

abort, begin, begin, begin, calc, calculate, calculateRead, calculateWrite, commit, end, exec, execute, executeRead, executeWrite, isInTransaction, promote, promote, transactionMode, transactionType

Method Detail

containsGraph

public boolean containsGraph(Node graphNode)

Description copied from interface: DatasetGraph

Does the DatasetGraph contain a specific named graph? Whether a dataset contains a graph if there are no triples is not defined - see the specific implementation. Some datasets are "open" - they have all graphs even if no triples and this returns true always.

Specified by:

containsGraph in interface DatasetGraph

Returns:

boolean

getDefaultGraph

public abstract Graph getDefaultGraph()

Description copied from interface: DatasetGraph

Get the default graph as a Jena Graph

Specified by:

getDefaultGraph in interface DatasetGraph

getUnionGraph

public Graph getUnionGraph()

Description copied from interface: DatasetGraph

Return a Graph that is the union of all named graphs in this dataset. This union graph is read-only (its prefix mapping in the current JVM may be changed but that may not persist).

Specified by:

getUnionGraph in interface DatasetGraph

getGraph

public abstract Graph getGraph(Node graphNode)

Description copied from interface: DatasetGraph

Get the graph named by graphNode : returns null when there is no such graph. NB Whether a dataset contains a graph if there are no triples is not defined - see the specific implementation. Some datasets are "open" - they have all graphs even if no triples.

Specified by:

getGraph in interface DatasetGraph

addGraph

public abstract void addGraph(Node graphName,
                              Graph graph)

Description copied from interface: DatasetGraph

Add the given graph to the dataset. Replaces any existing data for the named graph; to add data, get the graph and add triples to it, or add quads to the dataset. Do not assume that the same Java object is returned by DatasetGraph.getGraph(org.apache.jena.graph.Node)

Specified by:

addGraph in interface DatasetGraph

removeGraph

public abstract void removeGraph(Node graphName)

Description copied from interface: DatasetGraph

Remove all data associated with the named graph. This will include prefixes associated with the graph.

Specified by:

removeGraph in interface DatasetGraph

setDefaultGraph

public void setDefaultGraph(Graph g)

Description copied from interface: DatasetGraph

Set the default graph. Set the active graph if it was null. This replaces the contents default graph, not merge data into it. Do not assume that the same object is returned by DatasetGraph.getDefaultGraph()

Specified by:

setDefaultGraph in interface DatasetGraph

add

public void add(Quad quad)

Description copied from interface: DatasetGraph

Add a quad

Specified by:

add in interface DatasetGraph

delete

public void delete(Quad quad)

Description copied from interface: DatasetGraph

Delete a quad

Specified by:

delete in interface DatasetGraph

add

public void add(Node g,
                Node s,
                Node p,
                Node o)

Description copied from interface: DatasetGraph

Add a quad

Specified by:

add in interface DatasetGraph

delete

public void delete(Node g,
                   Node s,
                   Node p,
                   Node o)

Description copied from interface: DatasetGraph

Delete a quad

Specified by:

delete in interface DatasetGraph

deleteAny

public void deleteAny(Node g,
                      Node s,
                      Node p,
                      Node o)

Description copied from interface: DatasetGraph

Delete any quads matching the pattern

Specified by:

deleteAny in interface DatasetGraph

deleteAny

public static void deleteAny(DatasetGraph dsg,
                             Node g,
                             Node s,
                             Node p,
                             Node o)

find

public java.util.Iterator<Quad> find()

Description copied from interface: DatasetGraph

Iterate over all quads in the dataset graph

Specified by:

find in interface DatasetGraph

find

public java.util.Iterator<Quad> find(Quad quad)

Description copied from interface: DatasetGraph

Find matching quads in the dataset - may include wildcards, Node.ANY or null

Specified by:

find in interface DatasetGraph

See Also:

Graph.find(Triple)

contains

public boolean contains(Quad quad)

Description copied from interface: DatasetGraph

Test whether the dataset contains a quad (including default graph)- may include wildcards, Node.ANY or null

Specified by:

contains in interface DatasetGraph

contains

public boolean contains(Node g,
                        Node s,
                        Node p,
                        Node o)

Description copied from interface: DatasetGraph

Test whether the dataset (including default graph) contains a quad - may include wildcards, Node.ANY or null

Specified by:

contains in interface DatasetGraph

clear

public void clear()

Description copied from interface: DatasetGraph

Remove everything - remove all named graphs, clear the default graph

Specified by:

clear in interface DatasetGraph

isEmpty

public boolean isEmpty()

Description copied from interface: DatasetGraph

Test whether the dataset is empty

Specified by:

isEmpty in interface DatasetGraph

size

public long size()

Description copied from interface: DatasetGraph

Get the size (number of named graphs) - may be -1 for unknown

Specified by:

size in interface DatasetGraph

getLock

public Lock getLock()

Description copied from interface: DatasetGraph

Return a lock for the dataset to help with concurrency control

Specified by:

getLock in interface DatasetGraph

See Also:

Lock

getContext

public Context getContext()

Description copied from interface: DatasetGraph

Get the context associated with this object - may be null

Specified by:

getContext in interface DatasetGraph

close

public void close()

Description copied from interface: DatasetGraph

Close the dataset

Specified by:

close in interface org.apache.jena.atlas.lib.Closeable

Specified by:

close in interface DatasetGraph

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object