com.franz.agraph.repository
Class AGStreamTupleQuery

java.lang.Object
  org.openrdf.query.impl.AbstractOperation
      org.openrdf.query.impl.AbstractQuery
          com.franz.agraph.repository.AGQuery
              com.franz.agraph.repository.AGTupleQuery
                  com.franz.agraph.repository.AGStreamTupleQuery

All Implemented Interfaces:

Operation, Query, TupleQuery

public class AGStreamTupleQuery
extends AGTupleQuery
implements 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.openrdf.query.QueryLanguage, String)

Field Summary

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

RDFS_PLUS_PLUS, RESTRICTION, SPARQL_COVERAGE_PLANNER, SPARQL_IDENTITY_PLANNER

Constructor Summary

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

Method Summary

TupleQueryResult	evaluate() Returns a result object that will read from the http response as results are requested, by TupleQueryResult.hasNext().
void	evaluate(TupleQueryResultHandler handler)

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

count

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

analyze, getBindingsArray, getEngine, getEntailmentRegime, getLanguage, getLimit, getName, getOffset, getPlanner, getQueryString, isCheckVariables, isPrepared, setCheckVariables, setEngine, setEntailmentRegime, setIncludeInferred, setLimit, setOffset, setPlanner, setPrepared, setSaveName, toString

Methods inherited from class org.openrdf.query.impl.AbstractQuery

getMaxQueryTime, setMaxQueryTime

Methods inherited from class org.openrdf.query.impl.AbstractOperation

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

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.openrdf.query.Query

getMaxQueryTime, setMaxQueryTime

Methods inherited from interface org.openrdf.query.Operation

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

Constructor Detail

AGStreamTupleQuery

public AGStreamTupleQuery(AGTupleQuery query)

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

Parameters:

query - to wrap

Method Detail

evaluate

public TupleQueryResult evaluate()
                          throws 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 TupleQuery

Overrides:

evaluate in class AGTupleQuery

Throws:

QueryEvaluationException

evaluate

public void evaluate(TupleQueryResultHandler handler)
              throws QueryEvaluationException,
                     TupleQueryResultHandlerException

Specified by:

evaluate in interface TupleQuery

Overrides:

evaluate in class AGTupleQuery

Throws:

QueryEvaluationException

TupleQueryResultHandlerException