org.apache.clerezza.rdf.jena.tdb.storage

Class SingleTdbDatasetTcProvider

java.lang.Object

org.apache.clerezza.rdf.jena.tdb.storage.SingleTdbDatasetTcProvider

All Implemented Interfaces:

QueryableTcProvider, TcProvider, WeightedTcProvider

@Service(value={WeightedTcProvider.class,TcProvider.class,QueryableTcProvider.class})
@Properties(value={@Property(name="tdb-dir"),@Property(name="default-graph-name"),@Property(name="sync-interval",intValue=6),@Property(name="weight",intValue=105),@Property(name="general.purpose.tc",boolValue=true)})
public class SingleTdbDatasetTcProvider
extends Object
implements WeightedTcProvider

WeightedTcProvider implementation for Jena TDB that uses a single Dataset to store all created Graph and MGraph instances.

The TDB_DIR is uses to configure the directory on the disc. It supports property substitution '${property}' based on properties defined in the BundleContext.getProperty(String) and System.getProperty(String). This is to easily allow configurations such as "${myHome}/myRdfStore"

The DEFAULT_GRAPH_NAME property can be used to define the name of the Graph that exposes the Dataset.getDefaultModel() as both TcProvider.getGraph(UriRef) and TcProvider.getMGraph(UriRef). This easily allows to access the union graph of the Jena TDB dataset.

This TcProvider requires an configuration and uses the configuration factory. Therefore it will be bot active until a valid configuration is parsed to the ConfigurationAdmin service. However it supports multiple instances to be created.

Users that want to use multiple instances will need to use special filters to ensure that the correct instance is injected to components. As by default the instance with the highest WEIGHT will be used by Clerezza to create instances. A good practice to filter for multiple instances is to add an additional user defined key to the configuration that can later be used for filtering. Such additional keys will be savely ignored by this implementation.

Author:

Rupert Westenthaler, MInto van der Sluis

Field Summary

Fields

Modifier and Type	Field and Description
static String	DEFAULT_GRAPH_NAME
static int	DEFAULT_SYNC_INTERVAL
static int	MIN_SYNC_INTERVAL
static String	SYNC_INTERVAL
static String	TDB_DIR
static String	USE_GRAPH_NAME_SUFFIXES
static String	WEIGHT

Constructor Summary

Constructors

Constructor and Description
SingleTdbDatasetTcProvider() Default constructor used by OSGI
SingleTdbDatasetTcProvider(Dictionary<String,Object> config) Creates a TDB single dataset TcProvider based on the parsed configuration.

Method Summary

Methods

Modifier and Type	Method and Description
protected void	activate(org.osgi.service.component.ComponentContext ctx) Activate method used by OSGI
void	close() Closes this TcProvider instance and frees up all system resources.
Graph	createGraph(UriRef name, TripleCollection triples) Creates a Graph with a specified name
MGraph	createMGraph(UriRef name) Creates an initially empty MGraph with a specified name
protected void	deactivate(org.osgi.service.component.ComponentContext ctx) Deactivates this component.
void	deleteTripleCollection(UriRef name) Deletes the Graph or MGraph of a specified name.
Object	executeSparqlQuery(String query, UriRef defaultGraph) Executes any sparql query.
protected void	finalize() call close in finalisation
com.hp.hpl.jena.query.Dataset	getDataset()
Graph	getGraph(UriRef name) Get a Graph by its name
MGraph	getMGraph(UriRef name) Get an MGraph by its name.
Set<UriRef>	getNames(Graph graph) get a set of the names of a Graph
TripleCollection	getTriples(UriRef name) This method is used to get a TripleCollection indifferently whether it's a Graph or an MGraph.
int	getWeight() Get the weight of this provider.
Set<UriRef>	listGraphs() Lists the name of the Graphs available through this TcProvider, implementations may take into account the security context and omit Graphs for which access is not allowed.
Set<UriRef>	listMGraphs() Lists the name of the MGraphs available through this TcProvider, implementations may take into account the security context and omit MGraphs for which access is not allowed.
Set<UriRef>	listTripleCollections() Lists the name of the TripleCollections available through this TcProvider indifferently whether they are Graphs or an MGraphs, implementations may take into account the security context and omit TripleCollections for which access is not allowed.
void	setDataset(com.hp.hpl.jena.query.Dataset dataset)

Methods inherited from class java.lang.Object

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

Field Detail

TDB_DIR

public static final String TDB_DIR

See Also:

Constant Field Values

DEFAULT_GRAPH_NAME

public static final String DEFAULT_GRAPH_NAME

See Also:

Constant Field Values

WEIGHT

public static final String WEIGHT

See Also:

Constant Field Values

SYNC_INTERVAL

public static final String SYNC_INTERVAL

See Also:

Constant Field Values

USE_GRAPH_NAME_SUFFIXES

public static final String USE_GRAPH_NAME_SUFFIXES

See Also:

Constant Field Values

DEFAULT_SYNC_INTERVAL

public static final int DEFAULT_SYNC_INTERVAL

See Also:

Constant Field Values

MIN_SYNC_INTERVAL

public static final int MIN_SYNC_INTERVAL

See Also:

Constant Field Values

Constructor Detail

SingleTdbDatasetTcProvider

public SingleTdbDatasetTcProvider()

Default constructor used by OSGI

SingleTdbDatasetTcProvider

public SingleTdbDatasetTcProvider(Dictionary<String,Object> config)
                           throws org.osgi.service.cm.ConfigurationException,
                                  IOException

Creates a TDB single dataset TcProvider based on the parsed configuration.

The following properties are supported:

• TDB_DIR (required): The directory used by Jena TDB. Property substitution "${property-name}" with System.getProperties() is supported.
• DEFAULT_GRAPH_NAME: The name (UriRef) of the Graph that exports the union graph. This graph allows to query triples in any named model managed by this TcProvider.
• SYNC_INTERVAL: The sync interval that is used to write changes in the graph to the file system. If missing the DEFAULT_SYNC_INTERVAL is used. Values lower than MIN_SYNC_INTERVAL are ignored
• WEIGHT: The weight of this TcProvider. If missing 0 is used as weight.

NOTE Users need to call close() to free up system resources when they are no longer need this instance.

Parameters:

config - The configuration

Throws:

IOException - the

org.osgi.service.cm.ConfigurationException

Method Detail

activate

@Activate
protected void activate(org.osgi.service.component.ComponentContext ctx)
                 throws org.osgi.service.cm.ConfigurationException,
                        IOException

Activate method used by OSGI

Parameters:

ctx -

Throws:

org.osgi.service.cm.ConfigurationException

IOException

finalize

protected void finalize()
                 throws Throwable

call close in finalisation

Overrides:

finalize in class Object

Throws:

Throwable

close

public void close()

Closes this TcProvider instance and frees up all system resources. This method needs only to be called when using this TcProvider outside an OSGI environment.

deactivate

@Deactivate
protected void deactivate(org.osgi.service.component.ComponentContext ctx)

Deactivates this component. Called by the OSGI environment if this component gets deactivated.

Parameters:

ctx - the ComponentContext. May be null

getGraph

public Graph getGraph(UriRef name)
               throws NoSuchEntityException

Description copied from interface: TcProvider

Get a Graph by its name

Specified by:

getGraph in interface TcProvider

Parameters:

name - the name of the Graph

Returns:

the Graph with the specified name

Throws:

NoSuchEntityException - if there is no Graph with the specified name

getMGraph

public MGraph getMGraph(UriRef name)
                 throws NoSuchEntityException

Description copied from interface: TcProvider

Get an MGraph by its name. The instances returned in different invocations are equals.

Specified by:

getMGraph in interface TcProvider

Returns:

name the MGraph with the specified name

Throws:

NoSuchEntityException - if there is no MGraph with the specified name

getTriples

public TripleCollection getTriples(UriRef name)
                            throws NoSuchEntityException

Description copied from interface: TcProvider

This method is used to get a TripleCollection indifferently whether it's a Graph or an MGraph. If the name names an MGraph the result is the same as when invoking getMGraph with that argument, analogously for GraphS the method returns an instance equals to what getGraph would return.

Specified by:

getTriples in interface TcProvider

Parameters:

name - the name of the Graph or MGraph

Returns:

the Graph or MGraph

Throws:

NoSuchEntityException - if there is no Graph or MGraph with the specified name

listGraphs

public Set<UriRef> listGraphs()

Description copied from interface: TcProvider

Lists the name of the Graphs available through this TcProvider, implementations may take into account the security context and omit Graphs for which access is not allowed.

Specified by:

listGraphs in interface TcProvider

Returns:

the list of Graphs

listMGraphs

public Set<UriRef> listMGraphs()

Description copied from interface: TcProvider

Lists the name of the MGraphs available through this TcProvider, implementations may take into account the security context and omit MGraphs for which access is not allowed.

Specified by:

listMGraphs in interface TcProvider

Returns:

the list of MGraphs

listTripleCollections

public Set<UriRef> listTripleCollections()

Description copied from interface: TcProvider

Lists the name of the TripleCollections available through this TcProvider indifferently whether they are Graphs or an MGraphs, implementations may take into account the security context and omit TripleCollections for which access is not allowed.

Specified by:

listTripleCollections in interface TcProvider

Returns:

the list of TripleCollections

createMGraph

public MGraph createMGraph(UriRef name)
                    throws UnsupportedOperationException,
                           EntityAlreadyExistsException

Description copied from interface: TcProvider

Creates an initially empty MGraph with a specified name

Specified by:

createMGraph in interface TcProvider

Parameters:

name - names the new MGraph

Returns:

the newly created MGraph

Throws:

UnsupportedOperationException - if this provider doesn't support creating MGraphS

EntityAlreadyExistsException - if an MGraph with the specified name already exists

createGraph

public Graph createGraph(UriRef name,
                TripleCollection triples)
                  throws UnsupportedOperationException,
                         EntityAlreadyExistsException

Description copied from interface: TcProvider

Creates a Graph with a specified name

Specified by:

createGraph in interface TcProvider

Parameters:

name - the name of the Graph to be created

triples - the triples of the new Graph

Returns:

the newly created Graph

Throws:

UnsupportedOperationException - if this provider doesn't support creating GraphS

EntityAlreadyExistsException - if a Graph with the specified name already exists

deleteTripleCollection

public void deleteTripleCollection(UriRef name)
                            throws UnsupportedOperationException,
                                   NoSuchEntityException,
                                   EntityUndeletableException

Description copied from interface: TcProvider

Deletes the Graph or MGraph of a specified name. If name references a Graph and the graph has other names, it will still be available with those other names.

Specified by:

deleteTripleCollection in interface TcProvider

Parameters:

name - the entity to be removed

Throws:

UnsupportedOperationException - if this provider doesn't support entities deletion.

NoSuchEntityException - if name doesn't refer to a Graph or an MGraph.

EntityUndeletableException - if the specified Graph is undeletable

getNames

public Set<UriRef> getNames(Graph graph)

Description copied from interface: TcProvider

get a set of the names of a Graph

Specified by:

getNames in interface TcProvider

Returns:

the set names of Graph, the set is empty if Graph is unknown

getWeight

public int getWeight()

Description copied from interface: WeightedTcProvider

Get the weight of this provider. TcManager will prioritize TcProviders with greater weight.

Specified by:

getWeight in interface WeightedTcProvider

Returns:

a positive number indicating the weight of the provider

executeSparqlQuery

public Object executeSparqlQuery(String query,
                        UriRef defaultGraph)

Description copied from interface: QueryableTcProvider

Executes any sparql query. The type of the result object will vary depending on the type of the query.

Specified by:

executeSparqlQuery in interface QueryableTcProvider

Parameters:

query - the sparql query to execute

Returns:

the resulting ResultSet, Graph or Boolean value

getDataset

public com.hp.hpl.jena.query.Dataset getDataset()

setDataset

public void setDataset(com.hp.hpl.jena.query.Dataset dataset)