Package com.franz.agraph.repository

Class AGStreamTupleQuery

java.lang.Object

org.eclipse.rdf4j.query.impl.AbstractOperation

org.eclipse.rdf4j.query.impl.AbstractQuery

com.franz.agraph.repository.AGQuery

com.franz.agraph.repository.AGTupleQuery

com.franz.agraph.repository.AGStreamTupleQuery

All Implemented Interfaces:

org.eclipse.rdf4j.query.Operation, org.eclipse.rdf4j.query.Query, org.eclipse.rdf4j.query.TupleQuery

public class AGStreamTupleQuery
extends AGTupleQuery
implements org.eclipse.rdf4j.query.TupleQuery

Wraps an AGTupleQuery to provide streaming results. The default, TupleQueryResultParser and TupleQueryResultBuilder use SAX to parse and an ArrayList to collect results, so AGTupleQuery.evaluate() does not return until the entire stream is parsed.

AGStreamTupleQuery uses XMLStreamReader, so the result is pulled from the http response stream as methods such as TupleQueryResult.hasNext() are called.

Usage:

 AGTupleQuery query = conn.prepareTupleQuery(QueryLanguage.SPARQL, "SELECT ...");
 query = new AGStreamTupleQuery(query);
 TupleQueryResult results = query.evaluate();
 ...
 

Since:

v4.3

See Also:

• AGRepositoryConnection.prepareTupleQuery(org.eclipse.rdf4j.query.QueryLanguage, String)

Nested Class Summary

Nested classes/interfaces inherited from interface org.eclipse.rdf4j.query.Query

org.eclipse.rdf4j.query.Query.QueryType

Field Summary

Fields inherited from class com.franz.agraph.repository.AGQuery

RDFS_PLUS_PLUS, RESTRICTION, SPARQL_COVERAGE_PLANNER, SPARQL_IDENTITY_PLANNER

Constructor Summary

Constructors

Constructor	Description
AGStreamTupleQuery(AGTupleQuery query)	Wraps a query with this object that will stream the response.

Method Summary

Modifier and Type	Method	Description
org.eclipse.rdf4j.query.TupleQueryResult	evaluate()	Returns a result object that will read from the http response as results are requested, by TupleQueryResult.hasNext().
void	evaluate(org.eclipse.rdf4j.query.TupleQueryResultHandler handler)

Methods inherited from class com.franz.agraph.repository.AGTupleQuery

count, download, download, stream

Methods inherited from class com.franz.agraph.repository.AGQuery

analyze, download, download, download, download, getBaseURI, getBindingsArray, getEngine, getEntailmentRegime, getFranzOptionPrefixString, getLanguage, getLimit, getName, getOffset, getPlanner, getQueryString, hashCode, isCheckVariables, isLoggingEnabled, isPrepared, setCheckVariables, setEngine, setEntailmentRegime, setIncludeInferred, setLimit, setLoggingEnabled, setOffset, setPlanner, setPrepared, setSaveName, stream, stream, toString

Methods inherited from class org.eclipse.rdf4j.query.impl.AbstractQuery

getMaxQueryTime, setMaxQueryTime

Methods inherited from class org.eclipse.rdf4j.query.impl.AbstractOperation

clearBindings, getBindings, getDataset, getIncludeInferred, getMaxExecutionTime, removeBinding, setBinding, setDataset, setMaxExecutionTime

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.eclipse.rdf4j.query.Operation

clearBindings, getBindings, getDataset, getIncludeInferred, getMaxExecutionTime, removeBinding, setBinding, setDataset, setIncludeInferred, setMaxExecutionTime

Methods inherited from interface org.eclipse.rdf4j.query.Query

explain, getMaxQueryTime, setMaxQueryTime

Constructor Details

AGStreamTupleQuery

public AGStreamTupleQuery(AGTupleQuery query)

Wraps a query with this object that will stream the response.

Parameters:

query - to wrap

Method Details

evaluate

public org.eclipse.rdf4j.query.TupleQueryResult evaluate()
                                                  throws org.eclipse.rdf4j.query.QueryEvaluationException

Returns a result object that will read from the http response as results are requested, by TupleQueryResult.hasNext(). (Note that TupleQueryResult.next() does not actually do the work if hasNext() is called first.)

Specified by:

evaluate in interface org.eclipse.rdf4j.query.TupleQuery

Overrides:

evaluate in class AGTupleQuery

Throws:

org.eclipse.rdf4j.query.QueryEvaluationException

evaluate

public void evaluate(org.eclipse.rdf4j.query.TupleQueryResultHandler handler)
              throws org.eclipse.rdf4j.query.QueryEvaluationException,
org.eclipse.rdf4j.query.TupleQueryResultHandlerException

Specified by:

evaluate in interface org.eclipse.rdf4j.query.TupleQuery

Overrides:

evaluate in class AGTupleQuery

Throws:

org.eclipse.rdf4j.query.QueryEvaluationException

org.eclipse.rdf4j.query.TupleQueryResultHandlerException