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ARQ is a SPARQL 1.1 query engine for Apache Jena
/*
* 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.query;
import java.io.InputStream ;
import java.util.List ;
import org.apache.jena.atlas.io.IO ;
import org.apache.jena.atlas.logging.Log ;
import org.apache.jena.rdf.model.Model ;
import org.apache.jena.rdf.model.ModelFactory ;
import org.apache.jena.riot.Lang ;
import org.apache.jena.riot.ResultSetMgr ;
import org.apache.jena.shared.NotFoundException ;
import org.apache.jena.sparql.engine.QueryIterator ;
import org.apache.jena.sparql.engine.ResultSetStream ;
import org.apache.jena.sparql.graph.GraphFactory ;
import org.apache.jena.sparql.resultset.* ;
import org.apache.jena.sparql.sse.Item ;
import org.apache.jena.sparql.sse.SSE ;
import org.apache.jena.sparql.sse.builders.BuilderTable ;
import org.apache.jena.util.FileManager ;
/** ResultSetFactory - make result sets from places other than a query. */
public class ResultSetFactory {
// See also ResultSetMgr -- this post-dates this code.
// Ideally, read operations here should call ResultSetMgr.
/**
* Load a result set from file or URL into a result set (memory backed).
*
* @param filenameOrURI
* @return ResultSet
*/
public static ResultSet load(String filenameOrURI) {
return load(filenameOrURI, null);
}
/**
* Load a result set from file or URL into a result set (memory backed).
*
* @param filenameOrURI
* @param format
* @return ResultSet
*/
public static ResultSet load(String filenameOrURI, ResultsFormat format) {
if (format == null)
format = ResultsFormat.guessSyntax(filenameOrURI);
InputStream in = IO.openFile(filenameOrURI) ;
return load(in, format) ;
}
/**
* Load a result set from input stream into a result set (memory backed).
*
* @param input
* @param format
* @return ResultSet
*/
public static ResultSet load(InputStream input, ResultsFormat format) {
if (format == null) {
Log.warn(ResultSet.class, "Null format - defaulting to XML");
format = ResultsFormat.FMT_RS_XML;
}
// Old World - new world
Lang lang = ResultsFormat.convert(format) ;
if ( lang != null )
return ResultSetMgr.read(input, lang) ;
if (format.equals(ResultsFormat.FMT_RS_JSON))
return JSONInput.fromJSON(input);
if (format.equals(ResultsFormat.FMT_RS_TSV))
return TSVInput.fromTSV(input);
if (format.equals(ResultsFormat.FMT_RS_CSV))
return CSVInput.fromCSV(input);
if (format.equals(ResultsFormat.FMT_RS_BIO))
return BIOInput.fromBIO(input);
if (format.equals(ResultsFormat.FMT_RS_XML))
return ResultSetFactory.fromXML(input);
if (format.equals(ResultsFormat.FMT_TEXT)) {
Log.warn(ResultSet.class, "Can't read a text result set");
throw new ResultSetException("Can't read a text result set");
}
if (format.equals(ResultsFormat.FMT_RDF_XML)) {
Model m = ModelFactory.createDefaultModel();
m.read(input, null);
return RDFInput.fromRDF(m);
}
if (format.equals(ResultsFormat.FMT_RDF_TTL)) {
Model m = ModelFactory.createDefaultModel();
m.read(input, null, "TURTLE");
return RDFInput.fromRDF(m);
}
if (format.equals(ResultsFormat.FMT_RDF_N3)) {
Model m = ModelFactory.createDefaultModel();
m.read(input, null, "N3");
return RDFInput.fromRDF(m);
}
if (format.equals(ResultsFormat.FMT_RDF_NT)) {
Model m = ModelFactory.createDefaultModel();
m.read(input, null, "N-TRIPLES");
return RDFInput.fromRDF(m);
}
Log.warn(ResultSet.class, "Unknown result set syntax: " + format);
return null;
}
/**
* Load a result set (or any other model) from file or URL
*
* @param filenameOrURI
* @return Model
*/
public static Model loadAsModel(String filenameOrURI) {
return loadAsModel(null, filenameOrURI, null);
}
/**
* Load a result set (or any other model) from file or URL
*
* @param model
* Load into this model (returned)
* @param filenameOrURI
* @return Model
*/
public static Model loadAsModel(Model model, String filenameOrURI) {
return loadAsModel(model, filenameOrURI, null);
}
/**
* Load a result set (or any other model) from file or URL
*
* @param filenameOrURI
* @param format
* @return Model
*/
public static Model loadAsModel(String filenameOrURI, ResultsFormat format) {
return loadAsModel(null, filenameOrURI, format);
}
/**
* Load a result set (or any other model) from file or URL. Does not have to
* be a result set (e.g. CONSTRUCt results) but it does interpret the
* ResultSetFormat possibilities.
*
* @param model
* Load into this model (returned)
* @param filenameOrURI
* @param format
* @return Model
*/
public static Model loadAsModel(Model model, String filenameOrURI, ResultsFormat format) {
if (model == null)
model = GraphFactory.makeDefaultModel();
if (format == null)
format = ResultsFormat.guessSyntax(filenameOrURI);
if (format == null) {
Log.warn(ResultSet.class, "Null format - defaulting to XML");
format = ResultsFormat.FMT_RS_XML;
}
if (format.equals(ResultsFormat.FMT_TEXT)) {
Log.fatal(ResultSet.class, "Can't read a text result set");
throw new ResultSetException("Can't read a text result set");
}
if (format.equals(ResultsFormat.FMT_RS_XML) || format.equals(ResultsFormat.FMT_RS_JSON)) {
InputStream in = null;
try {
in = FileManager.get().open(filenameOrURI);
if (in == null)
throw new NotFoundException(filenameOrURI);
} catch (NotFoundException ex) {
throw new NotFoundException("File not found: " + filenameOrURI);
}
SPARQLResult x = null;
if (format.equals(ResultsFormat.FMT_RS_JSON))
x = JSONInput.make(in, GraphFactory.makeDefaultModel());
else
x = XMLInput.make(in, GraphFactory.makeDefaultModel());
if (x.isResultSet())
RDFOutput.encodeAsRDF(model, x.getResultSet());
else
RDFOutput.encodeAsRDF(model, x.getBooleanResult());
return model;
}
if (ResultsFormat.isRDFGraphSyntax(format))
return FileManager.get().readModel(model, filenameOrURI);
Log.fatal(ResultSet.class, "Unknown result set syntax: " + format);
return null;
}
/**
* Read in any kind of result kind (result set, boolean, graph) Guess the
* syntax based on filename/URL extension.
*/
public static SPARQLResult result(String filenameOrURI) {
return result(filenameOrURI, null);
}
/**
* Read in any kind of result kind (result set, boolean, graph)
*/
public static SPARQLResult result(String filenameOrURI, ResultsFormat format) {
if (format == null)
format = ResultsFormat.guessSyntax(filenameOrURI);
if (format == null) {
Log.warn(ResultSet.class, "Null format - defaulting to XML");
format = ResultsFormat.FMT_RS_XML;
}
if (format.equals(ResultsFormat.FMT_TEXT)) {
Log.fatal(ResultSet.class, "Can't read a text result set");
throw new ResultSetException("Can't read a text result set");
}
if (format.equals(ResultsFormat.FMT_RS_XML) || format.equals(ResultsFormat.FMT_RS_JSON)
|| format.equals(ResultsFormat.FMT_RS_TSV) || format.equals(ResultsFormat.FMT_RS_CSV)) {
InputStream in = null;
try {
in = FileManager.get().open(filenameOrURI);
if (in == null)
throw new NotFoundException(filenameOrURI);
} catch (NotFoundException ex) {
throw new NotFoundException("File not found: " + filenameOrURI);
}
SPARQLResult x = null;
if (format.equals(ResultsFormat.FMT_RS_JSON))
return JSONInput.make(in, GraphFactory.makeDefaultModel());
else if (format.equals(ResultsFormat.FMT_RS_XML))
return XMLInput.make(in, GraphFactory.makeDefaultModel());
else if (format.equals(ResultsFormat.FMT_RS_TSV)) {
ResultSet rs = TSVInput.fromTSV(in);
return new SPARQLResult(rs);
} else if (format.equals(ResultsFormat.FMT_RS_CSV)) {
ResultSet rs = CSVInput.fromCSV(in);
return new SPARQLResult(rs);
} else if (format.equals(ResultsFormat.FMT_RS_BIO)) {
ResultSet rs = BIOInput.fromBIO(in);
return new SPARQLResult(rs);
}
}
if (ResultsFormat.isRDFGraphSyntax(format)) {
Model model = FileManager.get().loadModel(filenameOrURI);
return new SPARQLResult(model);
}
Log.fatal(ResultSet.class, "Unknown result set syntax: " + format);
return null;
}
/**
* Read XML which is the format of the SPARQL result set format.
*
* @param in
* InputStream
* @return ResultSet
*/
public static ResultSet fromXML(InputStream in) {
return XMLInput.fromXML(in);
}
/**
* Read XML which is the format of the SPARQL result set format.
*
* @param str
* String to process
* @return ResultSet
*/
public static ResultSet fromXML(String str) {
return XMLInput.fromXML(str);
}
/**
* Read from an input stream which is the format of the SPARQL result set
* format in JSON.
*
* @param in
* InputStream
* @return ResultSet
*/
public static ResultSet fromJSON(InputStream in) {
return JSONInput.fromJSON(in);
}
/**
* Read from an input stream which is the format of the SPARQL result set
* format in TSV.
*
* @param in
* InputStream
* @return ResultSet
*/
public static ResultSet fromTSV(InputStream in) {
return TSVInput.fromTSV(in);
}
/**
* Read from an input stream which is the format of the SPARQL result set
* format in SSE.
*
* @param in
* InputStream
* @return ResultSet
*/
public static ResultSet fromSSE(InputStream in) {
Item item = SSE.parse(in);
Log.warn(ResultSet.class, "Reading SSE result set not full implemented");
// See SPARQLResult. Have a level of ResultSetFactory that does
// "get SPARQLResult".
// Or just boolean/result set because those are both srx. etc.
BuilderTable.build(item);
return null;
}
/**
* Turns an RDF model, with properties and classses from the result set
* vocabulary, into a SPARQL result set. The result set formed is a copy in
* memory.
*
* @param model
* @return ResultSet
*/
static public ResultSet makeResults(Model model) {
return new RDFInput(model);
}
/**
* Turns an RDF model, with properties and classses from the result set
* vocabulary, into a SPARQL result set which is rewindable (has a
* .reset()operation). The result set formed is a copy in memory.
*
* @param model
* @return ResultSetRewindable
*/
static public ResultSetRewindable makeRewindable(Model model) {
return new RDFInput(model);
}
/**
* Turn an existing result set into a rewindable one.
* May take a copy but this is not guarantted
* Uses up the result set passed in which is no longer valid as a ResultSet.
*
* @param resultSet
* @return ResultSetRewindable
*/
static public ResultSetRewindable makeRewindable(ResultSet resultSet) {
if ( resultSet instanceof ResultSetRewindable )
{
ResultSetRewindable rsw = (ResultSetRewindable)resultSet ;
rsw.reset() ;
return rsw ;
}
return new ResultSetMem(resultSet);
}
/**
* Turns an existing result set into one with peeking capabilities
*
* Using the returned result set consumes the result set passed in, the
* underlying result set must be at the start in order to be made peeking.
* If you create such a result set you should avoid accessing the underlying
* result set directly as this may cause results to be missed or put the
* returned peekable result set into an invalid state.
*
* Note that rewindable results may typically also be peekable so may
* be more broadly applicable if you can afford the cost of loading all the
* results into memory.
*
* @param resultSet
* Result set to wrap
* @return Peekable results
*/
static public ResultSetPeekable makePeekable(ResultSet resultSet) {
return new ResultSetPeeking(resultSet);
}
/**
* Take a copy of a result set - the result set returns is an in-memory
* copy. It is not attached to the original query execution object which can
* be closed.
*
* @param results
* @return ResultSet
*/
static public ResultSetRewindable copyResults(ResultSet results) {
return new ResultSetMem(results);
}
/**
* Build a result set from one of ARQ's lower level query iterator.
*
* @param queryIterator
* @param vars
* List of variables, by name, for the result set
* @return ResultSet
*/
static public ResultSet create(QueryIterator queryIterator, List vars) {
return new ResultSetStream(vars, null, queryIterator);
}
}
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