/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.jena.sparql.util ;
import java.util.List ;
import org.apache.jena.query.* ;
import org.apache.jena.rdf.model.Model ;
import org.apache.jena.rdf.model.RDFNode ;
import org.apache.jena.riot.Lang ;
import org.apache.jena.riot.RDFDataMgr ;
import org.apache.jena.riot.ResultSetMgr ;
import org.apache.jena.shared.PrefixMapping ;
import org.apache.jena.shared.impl.PrefixMappingImpl ;
import org.apache.jena.sparql.ARQConstants ;
import org.apache.jena.sparql.ARQException ;
import org.apache.jena.sparql.algebra.Algebra ;
import org.apache.jena.sparql.algebra.Op ;
import org.apache.jena.sparql.algebra.OpVars ;
import org.apache.jena.sparql.algebra.op.OpProject ;
import org.apache.jena.sparql.core.DatasetGraph ;
import org.apache.jena.sparql.core.Prologue ;
import org.apache.jena.sparql.core.Var ;
import org.apache.jena.sparql.engine.QueryIterator ;
import org.apache.jena.sparql.resultset.PlainFormat ;
import org.apache.jena.sparql.resultset.RDFOutput ;
import org.apache.jena.sparql.resultset.ResultSetApply ;
import org.apache.jena.sparql.resultset.ResultsFormat ;
import org.apache.jena.sparql.vocabulary.ResultSetGraphVocab ;
/** Some utilities for query processing. */
public class QueryExecUtils {
protected static PrefixMapping globalPrefixMap = new PrefixMappingImpl() ;
static {
globalPrefixMap.setNsPrefix("rdf", ARQConstants.rdfPrefix) ;
globalPrefixMap.setNsPrefix("rdfs", ARQConstants.rdfsPrefix) ;
globalPrefixMap.setNsPrefix("xsd", ARQConstants.xsdPrefix) ;
globalPrefixMap.setNsPrefix("owl" , ARQConstants.owlPrefix) ;
globalPrefixMap.setNsPrefix("ex" , "http://example.org/") ;
globalPrefixMap.setNsPrefix("ns" , "http://example.org/ns#") ;
globalPrefixMap.setNsPrefix("" , "http://example/") ;
}
protected static Prologue dftPrologue = new Prologue(globalPrefixMap) ;
public static void executeQuery(QueryExecution queryExecution) {
executeQuery(null, queryExecution) ;
}
public static void executeQuery(Prologue prologue, QueryExecution queryExecution) {
executeQuery(prologue, queryExecution, ResultsFormat.FMT_TEXT) ;
}
public static void executeQuery(Prologue prologue, QueryExecution queryExecution, ResultsFormat outputFormat) {
Query query = queryExecution.getQuery() ;
if ( prologue == null )
prologue = query.getPrologue() ;
if ( prologue == null )
prologue = dftPrologue ;
if ( query.isSelectType() )
doSelectQuery(prologue, queryExecution, outputFormat) ;
if ( query.isDescribeType() )
doDescribeQuery(prologue, queryExecution, outputFormat) ;
if ( query.isConstructType() )
doConstructQuery(prologue, queryExecution, outputFormat) ;
if ( query.isAskType() )
doAskQuery(prologue, queryExecution, outputFormat) ;
queryExecution.close() ;
}
public static void execute(Op op, DatasetGraph dsg) {
execute(op, dsg, ResultsFormat.FMT_TEXT) ;
}
public static void execute(Op op, DatasetGraph dsg, ResultsFormat outputFormat) {
QueryIterator qIter = Algebra.exec(op, dsg) ;
List<String> vars = null ;
if ( op instanceof OpProject )
vars = Var.varNames(((OpProject)op).getVars()) ;
else
// The variables defined in patterns (not Filters, nor NOT EXISTS,
// nor ORDER BY)
vars = Var.varNames(OpVars.visibleVars(op)) ;
ResultSet results = ResultSetFactory.create(qIter, vars) ;
outputResultSet(results, null, outputFormat) ;
}
@SuppressWarnings("deprecation")
public static void outputResultSet(ResultSet results, Prologue prologue, ResultsFormat outputFormat) {
// Proper ResultSet formats.
Lang lang = ResultsFormat.convert(outputFormat) ;
if ( lang != null ) {
ResultSetMgr.write(System.out, results, lang) ;
System.out.flush() ;
return ;
}
// Old way.
boolean done = false ;
if ( prologue == null )
prologue = new Prologue(globalPrefixMap) ;
if ( outputFormat.equals(ResultsFormat.FMT_UNKNOWN) )
outputFormat = ResultsFormat.FMT_TEXT ;
if ( outputFormat.equals(ResultsFormat.FMT_NONE) || outputFormat.equals(ResultsFormat.FMT_COUNT) ) {
int count = ResultSetFormatter.consume(results) ;
if ( outputFormat.equals(ResultsFormat.FMT_COUNT) ) {
System.out.println("Count = " + count) ;
}
done = true ;
}
if ( outputFormat.equals(ResultsFormat.FMT_RDF_XML) || outputFormat.equals(ResultsFormat.FMT_RDF_N3)
|| outputFormat.equals(ResultsFormat.FMT_RDF_TTL) ) {
Model m = RDFOutput.encodeAsModel(results) ;
m.setNsPrefixes(prologue.getPrefixMapping()) ;
m.setNsPrefix("rs", ResultSetGraphVocab.getURI()) ;
RDFDataMgr.write(System.out, m, Lang.TURTLE) ;
done = true ;
}
if ( outputFormat.equals(ResultsFormat.FMT_RS_XML) ) {
ResultSetFormatter.outputAsXML(System.out, results) ;
done = true ;
}
if ( outputFormat.equals(ResultsFormat.FMT_RS_JSON) ) {
ResultSetFormatter.outputAsJSON(System.out, results) ;
done = true ;
}
if ( outputFormat.equals(ResultsFormat.FMT_RS_SSE) ) {
ResultSetFormatter.outputAsSSE(System.out, results, prologue) ;
done = true ;
}
if ( outputFormat.equals(ResultsFormat.FMT_TEXT) ) {
ResultSetFormatter.out(System.out, results, prologue) ;
done = true ;
}
if ( outputFormat.equals(ResultsFormat.FMT_TUPLES) ) {
PlainFormat pFmt = new PlainFormat(System.out, prologue) ;
ResultSetApply a = new ResultSetApply(results, pFmt) ;
a.apply() ;
done = true ;
}
if ( outputFormat.equals(ResultsFormat.FMT_RS_CSV) ) {
ResultSetFormatter.outputAsCSV(System.out, results) ;
done = true ;
}
if ( outputFormat.equals(ResultsFormat.FMT_RS_TSV) ) {
ResultSetFormatter.outputAsTSV(System.out, results) ;
done = true ;
}
if ( outputFormat.equals(ResultsFormat.FMT_RS_BIO) ) {
ResultSetFormatter.outputAsBIO(System.out, results) ;
done = true ;
}
if ( !done )
System.err.println("Unknown format request: " + outputFormat) ;
results = null ;
System.out.flush() ;
}
private static void doSelectQuery(Prologue prologue, QueryExecution qe, ResultsFormat outputFormat) {
if ( prologue == null )
prologue = qe.getQuery().getPrologue() ;
if ( outputFormat == null || outputFormat == ResultsFormat.FMT_UNKNOWN )
outputFormat = ResultsFormat.FMT_TEXT ;
ResultSet results = qe.execSelect() ;
outputResultSet(results, prologue, outputFormat) ;
}
private static void doDescribeQuery(Prologue prologue, QueryExecution qe, ResultsFormat outputFormat) {
if ( outputFormat == null || outputFormat == ResultsFormat.FMT_UNKNOWN )
outputFormat = ResultsFormat.FMT_RDF_TTL ;
Model r = qe.execDescribe() ;
writeModel(prologue, r, outputFormat) ;
}
private static void doConstructQuery(Prologue prologue, QueryExecution qe, ResultsFormat outputFormat) {
if ( outputFormat == null || outputFormat == ResultsFormat.FMT_UNKNOWN )
outputFormat = ResultsFormat.FMT_RDF_TTL ;
Model r = qe.execConstruct() ;
writeModel(prologue, r, outputFormat) ;
}
private static void writeModel(Prologue prologue, Model model, ResultsFormat outputFormat) {
if ( outputFormat == null || outputFormat == ResultsFormat.FMT_UNKNOWN )
outputFormat = ResultsFormat.FMT_TEXT ;
if ( outputFormat.equals(ResultsFormat.FMT_NONE) )
return ;
if ( outputFormat.equals(ResultsFormat.FMT_TEXT) ) {
System.out.println("# ======== ") ;
RDFDataMgr.write(System.out, model, Lang.TURTLE) ;
System.out.println("# ======== ") ;
return ;
}
if ( outputFormat.equals(ResultsFormat.FMT_RDF_XML) ) {
model.write(System.out, "RDF/XML-ABBREV", null) ;
return ;
}
if ( outputFormat.equals(ResultsFormat.FMT_RDF_TTL) ) {
model.write(System.out, "N3", null) ;
return ;
}
if ( outputFormat.equals(ResultsFormat.FMT_RDF_N3) ) {
model.write(System.out, "N3", null) ;
return ;
}
if ( outputFormat.equals(ResultsFormat.FMT_RDF_NT) ) {
model.write(System.out, "N-TRIPLES", null) ;
return ;
}
System.err.println("Unknown format: " + outputFormat) ;
}
private static void doAskQuery(Prologue prologue, QueryExecution qe, ResultsFormat outputFormat) {
boolean b = qe.execAsk() ;
if ( outputFormat == null || outputFormat == ResultsFormat.FMT_UNKNOWN )
outputFormat = ResultsFormat.FMT_TEXT ;
if ( outputFormat.equals(ResultsFormat.FMT_NONE) )
return ;
if ( outputFormat.equals(ResultsFormat.FMT_RS_XML) ) {
ResultSetFormatter.outputAsXML(System.out, b) ;
return ;
}
if ( outputFormat.equals(ResultsFormat.FMT_RDF_N3) || outputFormat.equals(ResultsFormat.FMT_RDF_TTL) ) {
RDFOutput.outputAsRDF(System.out, "TURTLE", b) ;
System.out.flush() ;
return ;
}
if ( outputFormat.equals(ResultsFormat.FMT_RS_JSON) ) {
ResultSetFormatter.outputAsJSON(System.out, b) ;
return ;
}
if ( outputFormat.equals(ResultsFormat.FMT_TEXT) ) {
// ResultSetFormatter.out(System.out, b) ;
System.out.println("Ask => " + (b ? "Yes" : "No")) ;
return ;
}
if ( outputFormat.equals(ResultsFormat.FMT_RS_CSV) ) {
ResultSetFormatter.outputAsCSV(System.out, b) ;
return ;
}
if ( outputFormat.equals(ResultsFormat.FMT_RS_TSV) ) {
ResultSetFormatter.outputAsTSV(System.out, b) ;
return ;
}
System.err.println("Unknown format: " + outputFormat) ;
}
/**
* Execute a query, expecting the result to be one row, one column. Return
* that one RDFNode
*/
public static RDFNode getExactlyOne(String qs, Model model) {
return getExactlyOne(qs, DatasetFactory.create(model)) ;
}
/**
* Execute a query, expecting the result to be one row, one column. Return
* that one RDFNode
*/
public static RDFNode getExactlyOne(String qs, Dataset ds) {
Query q = QueryFactory.create(qs) ;
if ( q.getResultVars().size() != 1 )
throw new ARQException("getExactlyOne: Must have exactly one result columns") ;
String varname = q.getResultVars().get(0) ;
QueryExecution qExec = QueryExecutionFactory.create(q, ds) ;
return getExactlyOne(qExec, varname) ;
}
/**
* Execute, expecting the result to be one row, one column. Return that one
* RDFNode or throw an exception
*/
public static RDFNode getExactlyOne(QueryExecution qExec, String varname) {
try {
ResultSet rs = qExec.execSelect() ;
if ( !rs.hasNext() )
throw new ARQException("Not found: var ?" + varname) ;
QuerySolution qs = rs.nextSolution() ;
RDFNode r = qs.get(varname) ;
if ( rs.hasNext() )
throw new ARQException("More than one: var ?" + varname) ;
return r ;
}
finally {
qExec.close() ;
}
}
/**
* Execute, expecting the result to be one row, one column. Return that one
* RDFNode or null Throw excpetion if more than one.
*/
public static RDFNode getOne(QueryExecution qExec, String varname) {
try {
ResultSet rs = qExec.execSelect() ;
if ( !rs.hasNext() )
return null ;
QuerySolution qs = rs.nextSolution() ;
RDFNode r = qs.get(varname) ;
if ( rs.hasNext() ) {
QuerySolution qs2 = rs.next() ;
RDFNode r2 = qs2.get(varname) ;
if ( rs.hasNext() )
throw new ARQException("More than one: var ?" + varname + " -> " + r + ", " + r2 + ", ...") ;
else
throw new ARQException("Found two matches: var ?" + varname + " -> " + r + ", " + r2) ;
}
return r ;
}
finally {
qExec.close() ;
}
}
}