org.apache.jena.sparql.core

Class DatasetGraphWrapper

java.lang.Object

org.apache.jena.sparql.core.DatasetGraphWrapper

All Implemented Interfaces:

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

Direct Known Subclasses:

DatasetGraphMonitor, DatasetGraphReadOnly, DatasetGraphTrackActive, DatasetGraphViewGraphs, GraphStoreBasic

public class DatasetGraphWrapper
extends Object
implements DatasetGraph, org.apache.jena.atlas.lib.Sync

Constructor Summary

Constructors

Constructor and Description
DatasetGraphWrapper(DatasetGraph dsg)

Method Summary

Modifier and Type	Method and Description
void	abort() Abort a transaction - finish the transaction and undo any changes (if a "write" transaction)
void	add(Node g, Node s, Node p, Node o) Add a quad
void	add(Quad quad) Add a quad
void	addGraph(Node graphName, Graph graph) Add the given graph to the dataset.
void	begin(ReadWrite readWrite) Start either a READ or WRITE transaction
void	clear() Remove everything - remove all named graphs, clear the default graph
void	close() Close the dataset
void	commit() Commit a transaction - finish the transaction and make any changes permanent (if a "write" transaction)
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 specifc 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
void	end() Finish the transaction - if a write transaction and commit() has not been called, then abort
Iterator<Quad>	find() Iterate over all quads in the dataset graph
Iterator<Quad>	find(Node g, Node s, Node p, Node o) Find matching quads in the dataset (including default graph) - may include wildcards, Node.ANY or null
Iterator<Quad>	find(Quad quad) Find matching quads in the dataset - may include wildcards, Node.ANY or null
Iterator<Quad>	findNG(Node g, Node s, Node p, Node o) Find matching quads in the dataset in named graphs only - may include wildcards, Node.ANY or null
DatasetGraph	getBase() Recursively unwrap a DatasetGraphWrapped.
Context	getContext() Get the context associated with this object - may be null
Graph	getDefaultGraph() Get the default graph as a Jena Graph
Graph	getGraph(Node graphNode) Get the graph named by graphNode : returns null on no graph NB Whether a dataset contains a graph if there are no triples is not defined - see the specifc implementation.
Lock	getLock() Return a lock for the dataset to help with concurrency control
DatasetGraph	getWrapped() Return the DatasetGraph being wrapped.
boolean	isEmpty() Test whether the dataset is empty
boolean	isInTransaction() Say whether inside a transaction.
Iterator<Node>	listGraphNodes() Iterate over all names of named graphs
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
boolean	supportsTransactionAbort() Declare whether Transactional.abort() is supported.
boolean	supportsTransactions() A DatasetGraph supports tranactions if it provides Transactional.begin(org.apache.jena.query.ReadWrite)/ Transactional.commit()/Transactional.end().
void	sync()
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

DatasetGraphWrapper

public DatasetGraphWrapper(DatasetGraph dsg)

Method Detail

getWrapped

public final DatasetGraph getWrapped()

Return the DatasetGraph being wrapped.

getBase

public final DatasetGraph getBase()

Recursively unwrap a DatasetGraphWrapped.

Returns:

the first found DatasetGraph that is not an instance of DatasetGraphWrapper

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 specifc implementation. Some datasets are "open" - they have all graphs even if no triples and thsi returns true always.

Specified by:

containsGraph in interface DatasetGraph

Returns:

boolean

getDefaultGraph

public Graph getDefaultGraph()

Description copied from interface: DatasetGraph

Get the default graph as a Jena Graph

Specified by:

getDefaultGraph in interface DatasetGraph

getGraph

public Graph getGraph(Node graphNode)

Description copied from interface: DatasetGraph

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

Specified by:

getGraph in interface DatasetGraph

addGraph

public 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 void removeGraph(Node graphName)

Description copied from interface: DatasetGraph

Remove all data associated with the named 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

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

listGraphNodes

public Iterator<Node> listGraphNodes()

Description copied from interface: DatasetGraph

Iterate over all names of named graphs

Specified by:

listGraphNodes 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

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

find

public Iterator<Quad> find()

Description copied from interface: DatasetGraph

Iterate over all quads in the dataset graph

Specified by:

find in interface DatasetGraph

find

public 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)

find

public Iterator<Quad> find(Node g,
                           Node s,
                           Node p,
                           Node o)

Description copied from interface: DatasetGraph

Find matching quads in the dataset (including default graph) - may include wildcards, Node.ANY or null

Specified by:

find in interface DatasetGraph

See Also:

Graph.find(Node,Node,Node)

findNG

public Iterator<Quad> findNG(Node g,
                             Node s,
                             Node p,
                             Node o)

Description copied from interface: DatasetGraph

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

Specified by:

findNG in interface DatasetGraph

See Also:

Graph.find(Node,Node,Node)

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

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

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

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 String toString()

Overrides:

toString in class Object

sync

public void sync()

Specified by:

sync in interface org.apache.jena.atlas.lib.Sync

begin

public void begin(ReadWrite readWrite)

Description copied from interface: Transactional

Start either a READ or WRITE transaction

Specified by:

begin in interface Transactional

commit

public void commit()

Description copied from interface: Transactional

Commit a transaction - finish the transaction and make any changes permanent (if a "write" transaction)

Specified by:

commit in interface Transactional

abort

public void abort()

Description copied from interface: Transactional

Abort a transaction - finish the transaction and undo any changes (if a "write" transaction)

Specified by:

abort in interface Transactional

isInTransaction

public boolean isInTransaction()

Description copied from interface: Transactional

Say whether inside a transaction.

Specified by:

isInTransaction in interface Transactional

end

public void end()

Description copied from interface: Transactional

Finish the transaction - if a write transaction and commit() has not been called, then abort

Specified by:

end in interface Transactional

supportsTransactions

public boolean supportsTransactions()

Description copied from interface: DatasetGraph

A DatasetGraph supports tranactions if it provides Transactional.begin(org.apache.jena.query.ReadWrite)/ Transactional.commit()/Transactional.end(). There core storage DatasetGraph that provide fully serialized transactions. DatasetGraph that provide functionality acorss independent systems can not provide such strong guarantees. For example, they may use MRSW locking and some isolation control. Specifically, they do not necessarily provide Transactional.abort().

See DatasetGraph.supportsTransactionAbort() for Transactional.abort(). In addition, check details of a specific implementation.

Specified by:

supportsTransactions in interface DatasetGraph

supportsTransactionAbort

public boolean supportsTransactionAbort()

Description copied from interface: DatasetGraph

Declare whether Transactional.abort() is supported. This goes along with clearing up after exceptions inside application transaction code.

Specified by:

supportsTransactionAbort in interface DatasetGraph