jena-arq/src/main/java/org/apache/jena/sparql/resultset/XMLInputSAX.java - jena - Git at Google

 /*
  * 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.resultset ;

 import java.io.IOException ;
 import java.io.InputStream ;
 import java.io.Reader ;
 import java.util.ArrayList ;
 import java.util.List ;

 import org.apache.jena.atlas.logging.Log ;
 import org.apache.jena.datatypes.RDFDatatype ;
 import org.apache.jena.datatypes.TypeMapper ;
 import org.apache.jena.graph.Node ;
 import org.apache.jena.graph.NodeFactory ;
 import org.apache.jena.rdf.model.Model ;
 import org.apache.jena.riot.lang.LabelToNode;
 import org.apache.jena.riot.resultset.rw.XMLResults;
 import org.apache.jena.riot.system.SyntaxLabels;
 import org.apache.jena.sparql.core.Var ;
 import org.apache.jena.sparql.engine.ResultSetStream ;
 import org.apache.jena.sparql.engine.binding.Binding ;
 import org.apache.jena.sparql.engine.binding.BindingFactory ;
 import org.apache.jena.sparql.engine.binding.BindingMap ;
 import org.apache.jena.sparql.engine.iterator.QueryIterPlainWrapper ;
 import org.apache.jena.sparql.graph.GraphFactory ;
 import org.apache.jena.sparql.util.FmtUtils ;
 import org.apache.jena.vocabulary.RDF ;
 import org.xml.sax.* ;
 import org.xml.sax.helpers.XMLReaderFactory ;

 /** Code that reads an XML Result Set and builds the ARQ structure for the same. */
 // UNUSED
 class XMLInputSAX extends SPARQLResult {
     // See also XMLInputStAX, which is preferred.
     // SAX is not a streaming API - the SAX handler is called as fast as the
     // parser wants to call it, so the parser is calling for all the XML
     // and we have to build an in-memory structure (or the client application
     // would need to be inside the code path of the SAX handler).

     public XMLInputSAX(InputStream in, Model model) {
         worker(new InputSource(in), model) ;
     }

     public XMLInputSAX(Reader in, Model model) {
         worker(new InputSource(in), model) ;
     }

     public XMLInputSAX(String str, Model model) {
         worker(new InputSource(str), model) ;
     }

     private void worker(InputSource in, Model model) {
         if ( model == null )
             model = GraphFactory.makeJenaDefaultModel() ;

         try {
             XMLReader xr = XMLReaderFactory.createXMLReader() ;
             xr.setFeature("http://xml.org/sax/features/namespace-prefixes", true) ;
             // ResultSetXMLHandler1 handler = new ResultSetXMLHandler1() ;
             ResultSetXMLHandler2 handler = new ResultSetXMLHandler2() ;
             xr.setContentHandler(handler) ;
             xr.parse(in) ;
             if ( handler.isBooleanResult ) {
                 // Set superclass member
                 set(handler.askResult) ;
                 return ;
             }
             ResultSetStream rss = new ResultSetStream(handler.variables, model,
                                                       new QueryIterPlainWrapper(handler.results.iterator())) ;
             // Set superclass member
             set(rss) ;
         } catch (SAXException ex) {
             throw new ResultSetException("Problems parsing file (SAXException)", ex) ;
         } catch (IOException ex) {
             throw new ResultSetException("Problems parsing file (IOException)", ex) ;
         }

     }

     static class ResultSetXMLHandler2 implements ContentHandler {
         static final String namespace       = XMLResults.dfNamespace ;
         static final String variableElt     = XMLResults.dfVariable ;
         static final String resultElt       = XMLResults.dfSolution ;

         // Boolean
         boolean             isBooleanResult = false ;
         boolean             askResult       = false ;

         int                 rowCount        = 0 ;
         LabelToNode         bNodes          = SyntaxLabels.createLabelToNode();

         boolean             accumulate      = false ;
         StringBuffer        buff            = new StringBuffer() ;
         List<String>        variables       = new ArrayList<>() ;

         List<Binding>       results         = new ArrayList<>() ;
         // The current solution
         BindingMap          binding         = null ;

         // Note on terminology:
         // A "Binding" in ARQ is a set of name/value pairs
         // In the XML format is it one pair.

         // Current value
         String              varName ;
         String              datatype        = null ;
         String              langTag         = null ;

         String              rdfPrefix       = "rdf" ;

         ResultSetXMLHandler2() {}

         @Override
         public void setDocumentLocator(Locator locator) {}

         @Override
         public void startDocument() throws SAXException {}

         @Override
         public void endDocument() throws SAXException {}

         @Override
         public void startPrefixMapping(String prefix, String uri) throws SAXException {
             if ( uri.equals(RDF.getURI()) )
                 rdfPrefix = prefix ;
         }

         @Override
         public void endPrefixMapping(String prefix) throws SAXException {}

         @Override
         public void startElement(String ns, String localName, String qName, Attributes attrs) throws SAXException {
             if ( !ns.equals(namespace) ) {
                 // Wrong namespace
                 return ;
             }

             // ---- Header

             if ( localName.equals(XMLResults.dfVariable) ) {
                 if ( attrs.getValue(XMLResults.dfAttrVarName) != null ) {
                     String name = attrs.getValue(XMLResults.dfAttrVarName) ;
                     variables.add(name) ;
                 }
                 return ;
             }

             // ---- Results

             if ( localName.equals(XMLResults.dfResults) )
                 return ;

             // Boolean
             if ( localName.equals(XMLResults.dfBoolean) ) {
                 isBooleanResult = true ;
                 // Wait for the content
             }

             // ---- One solution

             if ( localName.equals(XMLResults.dfSolution) ) {
                 binding = BindingFactory.create() ;
                 return ;
             }

             // One variable

             if ( localName.equals(XMLResults.dfBinding) ) {
                 varName = attrs.getValue(XMLResults.dfAttrVarName) ;
                 return ;
             }

             // One value

             if ( localName.equals(XMLResults.dfURI) ) {
                 startElementURI(ns, localName, qName, attrs) ;
                 return ;
             }

             if ( localName.equals(XMLResults.dfLiteral) ) {
                 startElementLiteral(ns, localName, qName, attrs) ;
                 return ;
             }

             if ( localName.equals(XMLResults.dfBNode) ) {
                 startElementBNode(ns, localName, qName, attrs) ;
                 return ;
             }

             if ( localName.equals(XMLResults.dfUnbound) )
                 return ;

         }

         @Override
         public void endElement(String ns, String localName, String qName) throws SAXException {
             if ( !ns.equals(namespace) ) {
                 // Wrong namespace
                 return ;
             }

             // ---- Results

             if ( localName.equals(XMLResults.dfResults) )
                 return ;

             if ( localName.equals(XMLResults.dfBoolean) ) {
                 endElementBoolean() ;
                 return ;
             }

             // ---- One solution

             if ( localName.equals(XMLResults.dfSolution) ) {
                 varName = null ;
                 datatype = null ;
                 langTag = null ;
                 results.add(binding) ;
                 binding = null ;
                 return ;
             }

             // ---- One variable

             if ( localName.equals(XMLResults.dfBinding) ) {
                 varName = null ;
                 return ;
             }
             // ---- One value.

             if ( localName.equals(XMLResults.dfURI) ) {
                 endElementURI(ns, localName, qName) ;
                 return ;
             }

             if ( localName.equals(XMLResults.dfLiteral) ) {
                 endElementLiteral(ns, localName, qName) ;
                 return ;
             }

             if ( localName.equals(XMLResults.dfBNode) ) {
                 endElementBNode(ns, localName, qName) ;
                 return ;
             }

             if ( localName.equals(XMLResults.dfUnbound) )
                 return ;

         }

         private boolean checkVarName(String cxtMsg) {
             if ( cxtMsg == null )
                 cxtMsg = "" ;

             if ( varName == null ) {
                 Log.warn(this, "No variable name in scope: " + cxtMsg) ;
                 return false ;
             }
             if ( !variables.contains(varName) ) {
                 Log.warn(this, "Variable name '" + varName + "'not declared: " + cxtMsg) ;
                 return false ;
             }
             return true ;

         }

         private void startElementURI(String ns, String localName, String name, Attributes attrs) {
             startAccumulate() ;
         }

         private void endElementURI(String ns, String localName, String name) {
             endAccumulate() ;
             String uri = buff.toString() ;
             Node n = NodeFactory.createURI(uri) ;
             if ( checkVarName("URI: " + uri) )
                 addBinding(binding, Var.alloc(varName), n) ;
         }

         private void startElementLiteral(String ns, String localName, String name, Attributes attrs) {
             if ( attrs.getValue("datatype") != null )
                 datatype = attrs.getValue("datatype") ;

             if ( attrs.getValue("xml:lang") != null )
                 langTag = attrs.getValue("xml:lang") ;

             startAccumulate() ;
         }

         private void endElementLiteral(String ns, String localName, String name) {
             endAccumulate() ;
             String lexicalForm = buff.toString() ;

             RDFDatatype dType = null ;
             if ( datatype != null )
                 dType = TypeMapper.getInstance().getSafeTypeByName(datatype) ;

             Node n = NodeFactory.createLiteral(lexicalForm.toString(), langTag, dType) ;
             if ( checkVarName("Literal: " + FmtUtils.stringForNode(n)) )
                 addBinding(binding, Var.alloc(varName), n) ;

             // Finished value - clear intermediates (the wonders of event based
             // processing)
             this.datatype = null ;
             this.langTag = null ;
             this.varName = null ;
             return ;
         }

         private void endElementBoolean() {
             endAccumulate() ;
             String result = buff.toString() ;
             if ( result.equals("true") ) {
                 this.askResult = true ;
                 return ;
             }
             if ( result.equalsIgnoreCase("false") ) {
                 askResult = false ;
                 return ;
             }
             throw new ResultSetException("Unknown boolean value: " + result) ;
         }

         private void startElementBNode(String ns, String localName, String name, Attributes attrs) {
             startAccumulate() ;
         }

         private void endElementBNode(String ns, String localName, String name) {
             endAccumulate() ;
             String bnodeId = buff.toString() ;
             Node node = bNodes.get(null, bnodeId) ;
             if ( checkVarName("BNode: " + bnodeId) )
                 addBinding(binding, Var.alloc(varName), node) ;
         }

         private void startAccumulate() {
             buff.setLength(0) ;
             accumulate = true ;
         }

         private void endAccumulate() {
             accumulate = false ;
         }

         @Override
         public void characters(char[] chars, int start, int finish) throws SAXException {
             if ( accumulate ) {
                 if ( buff == null )
                     buff = new StringBuffer() ;
                 buff.append(chars, start, finish) ;
             }
         }

         @Override
         public void ignorableWhitespace(char[] ch, int start, int length) throws SAXException {}

         @Override
         public void processingInstruction(String target, String data) throws SAXException {}

         @Override
         public void skippedEntity(String name) throws SAXException {}

         static protected void addBinding(BindingMap binding, Var var, Node value) {
             Node n = binding.get(var);
             if ( n != null ) {
                 // Same - silently skip.
                 if ( n.equals(value) )
                     return;
                 Log.warn(SPARQLResult.class,
                          String.format("Multiple occurences of a binding for variable '%s' with different values - ignored", var.getName()));
                 return;
             }
             binding.add(var, value);
         }


     }
 }
	/*
	* 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.resultset ;

	import java.io.IOException ;
	import java.io.InputStream ;
	import java.io.Reader ;
	import java.util.ArrayList ;
	import java.util.List ;

	import org.apache.jena.atlas.logging.Log ;
	import org.apache.jena.datatypes.RDFDatatype ;
	import org.apache.jena.datatypes.TypeMapper ;
	import org.apache.jena.graph.Node ;
	import org.apache.jena.graph.NodeFactory ;
	import org.apache.jena.rdf.model.Model ;
	import org.apache.jena.riot.lang.LabelToNode;
	import org.apache.jena.riot.resultset.rw.XMLResults;
	import org.apache.jena.riot.system.SyntaxLabels;
	import org.apache.jena.sparql.core.Var ;
	import org.apache.jena.sparql.engine.ResultSetStream ;
	import org.apache.jena.sparql.engine.binding.Binding ;
	import org.apache.jena.sparql.engine.binding.BindingFactory ;
	import org.apache.jena.sparql.engine.binding.BindingMap ;
	import org.apache.jena.sparql.engine.iterator.QueryIterPlainWrapper ;
	import org.apache.jena.sparql.graph.GraphFactory ;
	import org.apache.jena.sparql.util.FmtUtils ;
	import org.apache.jena.vocabulary.RDF ;
	import org.xml.sax.* ;
	import org.xml.sax.helpers.XMLReaderFactory ;

	/** Code that reads an XML Result Set and builds the ARQ structure for the same. */
	// UNUSED
	class XMLInputSAX extends SPARQLResult {
	// See also XMLInputStAX, which is preferred.
	// SAX is not a streaming API - the SAX handler is called as fast as the
	// parser wants to call it, so the parser is calling for all the XML
	// and we have to build an in-memory structure (or the client application
	// would need to be inside the code path of the SAX handler).

	public XMLInputSAX(InputStream in, Model model) {
	worker(new InputSource(in), model) ;
	}

	public XMLInputSAX(Reader in, Model model) {
	worker(new InputSource(in), model) ;
	}

	public XMLInputSAX(String str, Model model) {
	worker(new InputSource(str), model) ;
	}

	private void worker(InputSource in, Model model) {
	if ( model == null )
	model = GraphFactory.makeJenaDefaultModel() ;

	try {
	XMLReader xr = XMLReaderFactory.createXMLReader() ;
	xr.setFeature("http://xml.org/sax/features/namespace-prefixes", true) ;
	// ResultSetXMLHandler1 handler = new ResultSetXMLHandler1() ;
	ResultSetXMLHandler2 handler = new ResultSetXMLHandler2() ;
	xr.setContentHandler(handler) ;
	xr.parse(in) ;
	if ( handler.isBooleanResult ) {
	// Set superclass member
	set(handler.askResult) ;
	return ;
	}
	ResultSetStream rss = new ResultSetStream(handler.variables, model,
	new QueryIterPlainWrapper(handler.results.iterator())) ;
	// Set superclass member
	set(rss) ;
	} catch (SAXException ex) {
	throw new ResultSetException("Problems parsing file (SAXException)", ex) ;
	} catch (IOException ex) {
	throw new ResultSetException("Problems parsing file (IOException)", ex) ;
	}

	}

	static class ResultSetXMLHandler2 implements ContentHandler {
	static final String namespace = XMLResults.dfNamespace ;
	static final String variableElt = XMLResults.dfVariable ;
	static final String resultElt = XMLResults.dfSolution ;

	// Boolean
	boolean isBooleanResult = false ;
	boolean askResult = false ;

	int rowCount = 0 ;
	LabelToNode bNodes = SyntaxLabels.createLabelToNode();

	boolean accumulate = false ;
	StringBuffer buff = new StringBuffer() ;
	List<String> variables = new ArrayList<>() ;

	List<Binding> results = new ArrayList<>() ;
	// The current solution
	BindingMap binding = null ;

	// Note on terminology:
	// A "Binding" in ARQ is a set of name/value pairs
	// In the XML format is it one pair.

	// Current value
	String varName ;
	String datatype = null ;
	String langTag = null ;

	String rdfPrefix = "rdf" ;

	ResultSetXMLHandler2() {}

	@Override
	public void setDocumentLocator(Locator locator) {}

	@Override
	public void startDocument() throws SAXException {}

	@Override
	public void endDocument() throws SAXException {}

	@Override
	public void startPrefixMapping(String prefix, String uri) throws SAXException {
	if ( uri.equals(RDF.getURI()) )
	rdfPrefix = prefix ;
	}

	@Override
	public void endPrefixMapping(String prefix) throws SAXException {}

	@Override
	public void startElement(String ns, String localName, String qName, Attributes attrs) throws SAXException {
	if ( !ns.equals(namespace) ) {
	// Wrong namespace
	return ;
	}

	// ---- Header

	if ( localName.equals(XMLResults.dfVariable) ) {
	if ( attrs.getValue(XMLResults.dfAttrVarName) != null ) {
	String name = attrs.getValue(XMLResults.dfAttrVarName) ;
	variables.add(name) ;
	}
	return ;
	}

	// ---- Results

	if ( localName.equals(XMLResults.dfResults) )
	return ;

	// Boolean
	if ( localName.equals(XMLResults.dfBoolean) ) {
	isBooleanResult = true ;
	// Wait for the content
	}

	// ---- One solution

	if ( localName.equals(XMLResults.dfSolution) ) {
	binding = BindingFactory.create() ;
	return ;
	}

	// One variable

	if ( localName.equals(XMLResults.dfBinding) ) {
	varName = attrs.getValue(XMLResults.dfAttrVarName) ;
	return ;
	}

	// One value

	if ( localName.equals(XMLResults.dfURI) ) {
	startElementURI(ns, localName, qName, attrs) ;
	return ;
	}

	if ( localName.equals(XMLResults.dfLiteral) ) {
	startElementLiteral(ns, localName, qName, attrs) ;
	return ;
	}

	if ( localName.equals(XMLResults.dfBNode) ) {
	startElementBNode(ns, localName, qName, attrs) ;
	return ;
	}

	if ( localName.equals(XMLResults.dfUnbound) )
	return ;

	}

	@Override
	public void endElement(String ns, String localName, String qName) throws SAXException {
	if ( !ns.equals(namespace) ) {
	// Wrong namespace
	return ;
	}

	// ---- Results

	if ( localName.equals(XMLResults.dfResults) )
	return ;

	if ( localName.equals(XMLResults.dfBoolean) ) {
	endElementBoolean() ;
	return ;
	}

	// ---- One solution

	if ( localName.equals(XMLResults.dfSolution) ) {
	varName = null ;
	datatype = null ;
	langTag = null ;
	results.add(binding) ;
	binding = null ;
	return ;
	}

	// ---- One variable

	if ( localName.equals(XMLResults.dfBinding) ) {
	varName = null ;
	return ;
	}
	// ---- One value.

	if ( localName.equals(XMLResults.dfURI) ) {
	endElementURI(ns, localName, qName) ;
	return ;
	}

	if ( localName.equals(XMLResults.dfLiteral) ) {
	endElementLiteral(ns, localName, qName) ;
	return ;
	}

	if ( localName.equals(XMLResults.dfBNode) ) {
	endElementBNode(ns, localName, qName) ;
	return ;
	}

	if ( localName.equals(XMLResults.dfUnbound) )
	return ;

	}

	private boolean checkVarName(String cxtMsg) {
	if ( cxtMsg == null )
	cxtMsg = "" ;

	if ( varName == null ) {
	Log.warn(this, "No variable name in scope: " + cxtMsg) ;
	return false ;
	}
	if ( !variables.contains(varName) ) {
	Log.warn(this, "Variable name '" + varName + "'not declared: " + cxtMsg) ;
	return false ;
	}
	return true ;

	}

	private void startElementURI(String ns, String localName, String name, Attributes attrs) {
	startAccumulate() ;
	}

	private void endElementURI(String ns, String localName, String name) {
	endAccumulate() ;
	String uri = buff.toString() ;
	Node n = NodeFactory.createURI(uri) ;
	if ( checkVarName("URI: " + uri) )
	addBinding(binding, Var.alloc(varName), n) ;
	}

	private void startElementLiteral(String ns, String localName, String name, Attributes attrs) {
	if ( attrs.getValue("datatype") != null )
	datatype = attrs.getValue("datatype") ;

	if ( attrs.getValue("xml:lang") != null )
	langTag = attrs.getValue("xml:lang") ;

	startAccumulate() ;
	}

	private void endElementLiteral(String ns, String localName, String name) {
	endAccumulate() ;
	String lexicalForm = buff.toString() ;

	RDFDatatype dType = null ;
	if ( datatype != null )
	dType = TypeMapper.getInstance().getSafeTypeByName(datatype) ;

	Node n = NodeFactory.createLiteral(lexicalForm.toString(), langTag, dType) ;
	if ( checkVarName("Literal: " + FmtUtils.stringForNode(n)) )
	addBinding(binding, Var.alloc(varName), n) ;

	// Finished value - clear intermediates (the wonders of event based
	// processing)
	this.datatype = null ;
	this.langTag = null ;
	this.varName = null ;
	return ;
	}

	private void endElementBoolean() {
	endAccumulate() ;
	String result = buff.toString() ;
	if ( result.equals("true") ) {
	this.askResult = true ;
	return ;
	}
	if ( result.equalsIgnoreCase("false") ) {
	askResult = false ;
	return ;
	}
	throw new ResultSetException("Unknown boolean value: " + result) ;
	}

	private void startElementBNode(String ns, String localName, String name, Attributes attrs) {
	startAccumulate() ;
	}

	private void endElementBNode(String ns, String localName, String name) {
	endAccumulate() ;
	String bnodeId = buff.toString() ;
	Node node = bNodes.get(null, bnodeId) ;
	if ( checkVarName("BNode: " + bnodeId) )
	addBinding(binding, Var.alloc(varName), node) ;
	}

	private void startAccumulate() {
	buff.setLength(0) ;
	accumulate = true ;
	}

	private void endAccumulate() {
	accumulate = false ;
	}

	@Override
	public void characters(char[] chars, int start, int finish) throws SAXException {
	if ( accumulate ) {
	if ( buff == null )
	buff = new StringBuffer() ;
	buff.append(chars, start, finish) ;
	}
	}

	@Override
	public void ignorableWhitespace(char[] ch, int start, int length) throws SAXException {}

	@Override
	public void processingInstruction(String target, String data) throws SAXException {}

	@Override
	public void skippedEntity(String name) throws SAXException {}

	static protected void addBinding(BindingMap binding, Var var, Node value) {
	Node n = binding.get(var);
	if ( n != null ) {
	// Same - silently skip.
	if ( n.equals(value) )
	return;
	Log.warn(SPARQLResult.class,
	String.format("Multiple occurences of a binding for variable '%s' with different values - ignored", var.getName()));
	return;
	}
	binding.add(var, value);
	}


	}
	}