org.dice_research.squirrel.fetcher.sparql

Class SparqlDatasetFetcher

java.lang.Object

org.dice_research.squirrel.fetcher.sparql.SparqlDatasetFetcher

All Implemented Interfaces:

Closeable, AutoCloseable, Fetcher

public class SparqlDatasetFetcher
extends Object
implements Fetcher

A simple Fetcher for SPARQL that tries to get DataSets from a SPARQL endpoint using the query .

Author:

Geraldo de Souza Jr (gsjunior@uni-paderborn.de)

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	SparqlDatasetFetcher.SelectedTriplesIterator

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	checkForUriType
protected File	dataDirectory
protected String	dataSetQuery The delay that the system will have between sending two queries.
protected int	delay
protected String	graphQuery
protected int	limit
private static org.slf4j.Logger	LOGGER

Constructor Summary

Constructors

Constructor and Description
SparqlDatasetFetcher()
SparqlDatasetFetcher(int delay)
SparqlDatasetFetcher(int delay, int begin, int limit)

Method Summary

Modifier and Type	Method and Description
void	close()
File	fetch(org.dice_research.squirrel.data.uri.CrawleableUri uri, Delayer delayer) Fetches a stream of data from the given URI by following the delay implemented by the given Delayer, stores it and returns a File object pointing to the stored data.
protected org.aksw.jena_sparql_api.core.QueryExecutionFactory	initQueryExecution(String uri)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.dice_research.squirrel.fetcher.Fetcher

fetch

Field Detail

LOGGER

private static final org.slf4j.Logger LOGGER

dataSetQuery

protected String dataSetQuery

The delay that the system will have between sending two queries.

graphQuery

protected String graphQuery

delay

protected int delay

limit

protected int limit

dataDirectory

protected File dataDirectory

checkForUriType

protected boolean checkForUriType

Constructor Detail

SparqlDatasetFetcher

public SparqlDatasetFetcher()

SparqlDatasetFetcher

public SparqlDatasetFetcher(int delay,
                            int begin,
                            int limit)

SparqlDatasetFetcher

public SparqlDatasetFetcher(int delay)

Method Detail

fetch

public File fetch(org.dice_research.squirrel.data.uri.CrawleableUri uri,
                  Delayer delayer)

Description copied from interface: Fetcher

Fetches a stream of data from the given URI by following the delay implemented by the given Delayer, stores it and returns a File object pointing to the stored data. If an error occurs, null is returned.

Specified by:

fetch in interface Fetcher

Parameters:

uri - The URI from which data should be fetched.

Returns:

A File object pointing to the downloaded data or null if an error occurred.

initQueryExecution

protected org.aksw.jena_sparql_api.core.QueryExecutionFactory initQueryExecution(String uri)
                                                                          throws ClassNotFoundException,
                                                                                 SQLException

Throws:

ClassNotFoundException

SQLException

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException