src/ooxml/java/org/apache/poi/xssf/extractor/XSSFExportToXml.java - poi - 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.poi.xssf.extractor;

 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Vector;

 import javax.xml.parsers.ParserConfigurationException;
 import javax.xml.transform.OutputKeys;
 import javax.xml.transform.Source;
 import javax.xml.transform.Transformer;
 import javax.xml.transform.TransformerException;
 import javax.xml.transform.TransformerFactory;
 import javax.xml.transform.dom.DOMSource;
 import javax.xml.transform.stream.StreamResult;
 import javax.xml.validation.Schema;
 import javax.xml.validation.SchemaFactory;
 import javax.xml.validation.Validator;

 import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
 import org.apache.poi.util.DocumentHelper;
 import org.apache.poi.xssf.usermodel.XSSFCell;
 import org.apache.poi.xssf.usermodel.XSSFMap;
 import org.apache.poi.xssf.usermodel.XSSFRow;
 import org.apache.poi.xssf.usermodel.XSSFSheet;
 import org.apache.poi.xssf.usermodel.XSSFTable;
 import org.apache.poi.xssf.usermodel.helpers.XSSFSingleXmlCell;
 import org.apache.poi.xssf.usermodel.helpers.XSSFXmlColumnPr;
 import org.openxmlformats.schemas.spreadsheetml.x2006.main.STXmlDataType;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.w3c.dom.NamedNodeMap;
 import org.w3c.dom.Node;
 import org.w3c.dom.NodeList;
 import org.xml.sax.SAXException;

 /**
  *
  * Maps an XLSX to an XML according to one of the mapping defined.
  *
  *
  * The output XML Schema must respect this limitations:
  *
  * <ul>
  * <li> all mandatory elements and attributes must be mapped (enable validation to check this)</li>
  *
  * <li> no &lt;any&gt; in complex type/element declaration </li>
  * <li> no &lt;anyAttribute&gt; attributes declaration </li>
  * <li> no recursive structures: recursive structures can't be nested more than one level </li>
  * <li> no abstract elements: abstract complex types can be declared but must not be used in elements. </li>
  * <li> no mixed content: an element can't contain simple text and child element(s) together </li>
  * <li> no &lt;substitutionGroup&gt; in complex type/element declaration </li>
  * </ul>
  */
 public class XSSFExportToXml implements Comparator<String>{

     private XSSFMap map;

     /**
      * Creates a new exporter and sets the mapping to be used when generating the XML output document
      *
      * @param map the mapping rule to be used
      */
     public XSSFExportToXml(XSSFMap map) {
         this.map = map;
     }

     /**
      *
      * Exports the data in an XML stream
      *
      * @param os OutputStream in which will contain the output XML
      * @param validate if true, validates the XML againts the XML Schema
      * @throws SAXException
      * @throws TransformerException
      * @throws ParserConfigurationException
      */
     public void exportToXML(OutputStream os, boolean validate) throws SAXException, ParserConfigurationException, TransformerException {
         exportToXML(os, "UTF-8", validate);
     }

     /**
      * Exports the data in an XML stream
      *
      * @param os OutputStream in which will contain the output XML
      * @param encoding the output charset encoding
      * @param validate if true, validates the XML againts the XML Schema
      * @throws SAXException
      * @throws ParserConfigurationException
      * @throws TransformerException
      * @throws InvalidFormatException
      */
     public void exportToXML(OutputStream os, String encoding, boolean validate) throws SAXException, ParserConfigurationException, TransformerException{
         List<XSSFSingleXmlCell> singleXMLCells = map.getRelatedSingleXMLCell();
         List<XSSFTable> tables = map.getRelatedTables();

         String rootElement = map.getCtMap().getRootElement();

         Document doc = DocumentHelper.createDocument();

         Element root = null;

         if (isNamespaceDeclared()) {
             root=doc.createElementNS(getNamespace(),rootElement);
         } else {
             root = doc.createElementNS("", rootElement);
         }
         doc.appendChild(root);


         List<String> xpaths = new Vector<String>();
         Map<String,XSSFSingleXmlCell> singleXmlCellsMappings = new HashMap<String,XSSFSingleXmlCell>();
         Map<String,XSSFTable> tableMappings = new HashMap<String,XSSFTable>();

         for(XSSFSingleXmlCell simpleXmlCell : singleXMLCells) {
             xpaths.add(simpleXmlCell.getXpath());
             singleXmlCellsMappings.put(simpleXmlCell.getXpath(), simpleXmlCell);
         }
         for(XSSFTable table : tables) {
             String commonXPath = table.getCommonXpath();
             xpaths.add(commonXPath);
             tableMappings.put(commonXPath, table);
         }


         Collections.sort(xpaths,this);

         for(String xpath : xpaths) {

             XSSFSingleXmlCell simpleXmlCell = singleXmlCellsMappings.get(xpath);
             XSSFTable table = tableMappings.get(xpath);

             if (!xpath.matches(".*\\[.*")) {

                 // Exports elements and attributes mapped with simpleXmlCell
                 if (simpleXmlCell!=null) {
                     XSSFCell cell = simpleXmlCell.getReferencedCell();
                     if (cell!=null) {
                         Node currentNode = getNodeByXPath(xpath,doc.getFirstChild(),doc,false);
                         STXmlDataType.Enum dataType = simpleXmlCell.getXmlDataType();
                         mapCellOnNode(cell,currentNode,dataType);
                     }
                 }

                 // Exports elements and attributes mapped with tables
                 if (table!=null) {

                     List<XSSFXmlColumnPr> tableColumns = table.getXmlColumnPrs();

                     XSSFSheet sheet = table.getXSSFSheet();

                     int startRow = table.getStartCellReference().getRow();
                     // In mappings created with Microsoft Excel the first row contains the table header and must be skipped
                     startRow +=1;

                     int endRow = table.getEndCellReference().getRow();

                     for(int i = startRow; i<= endRow; i++) {
                         XSSFRow row = sheet.getRow(i);

                         Node tableRootNode = getNodeByXPath(table.getCommonXpath(),doc.getFirstChild(),doc,true);

                         short startColumnIndex = table.getStartCellReference().getCol();
                         for(int j = startColumnIndex; j<= table.getEndCellReference().getCol();j++) {
                             XSSFCell cell = row.getCell(j);
                             if (cell!=null) {
                                 XSSFXmlColumnPr pointer = tableColumns.get(j-startColumnIndex);
                                 String localXPath = pointer.getLocalXPath();
                                 Node currentNode = getNodeByXPath(localXPath,tableRootNode,doc,false);
                                 STXmlDataType.Enum dataType = pointer.getXmlDataType();


                                 mapCellOnNode(cell,currentNode,dataType);
                             }

                         }

                     }


                 }
             } else {
                 // TODO:  implement filtering management in xpath
             }
         }

         boolean isValid = true;
         if (validate) {
             isValid =isValid(doc);
         }


         if (isValid) {

             /////////////////
             //Output the XML

             //set up a transformer
             TransformerFactory transfac = TransformerFactory.newInstance();
             Transformer trans = transfac.newTransformer();
             trans.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
             trans.setOutputProperty(OutputKeys.INDENT, "yes");
             trans.setOutputProperty(OutputKeys.ENCODING, encoding);

             //create string from xml tree

             StreamResult result = new StreamResult(os);
             DOMSource source = new DOMSource(doc);
             trans.transform(source, result);

         }
     }


     /**
      * Validate the generated XML against the XML Schema associated with the XSSFMap
      *
      * @param xml the XML to validate
      * @return true, if document is valid
      */
     private boolean isValid(Document xml) throws SAXException{
         boolean isValid = false;
         try{
             String language = "http://www.w3.org/2001/XMLSchema";
             SchemaFactory factory = SchemaFactory.newInstance(language);

             Source source = new DOMSource(map.getSchema());
             Schema schema = factory.newSchema(source);
             Validator validator = schema.newValidator();
             validator.validate(new DOMSource(xml));
             //if no exceptions where raised, the document is valid
             isValid=true;


         } catch(IOException e) {
             e.printStackTrace();
         }
         return isValid;
     }


     private void mapCellOnNode(XSSFCell cell, Node node, STXmlDataType.Enum  outputDataType) {

         String value ="";
         switch (cell.getCellType()) {

         case XSSFCell.CELL_TYPE_STRING: value = cell.getStringCellValue(); break;
         case XSSFCell.CELL_TYPE_BOOLEAN: value += cell.getBooleanCellValue(); break;
         case XSSFCell.CELL_TYPE_ERROR: value = cell.getErrorCellString();  break;
         case XSSFCell.CELL_TYPE_FORMULA: value = cell.getStringCellValue(); break;
         case XSSFCell.CELL_TYPE_NUMERIC: value += cell.getRawValue(); break;
         default: ;

         }
         if (node instanceof Element) {
             Element currentElement = (Element) node;
             currentElement.setTextContent(value);
         } else {
             node.setNodeValue(value);
         }
     }

     private String removeNamespace(String elementName) {
         return elementName.matches(".*:.*")?elementName.split(":")[1]:elementName;
     }


     private Node getNodeByXPath(String xpath,Node rootNode,Document doc,boolean createMultipleInstances) {
         String[] xpathTokens = xpath.split("/");


         Node currentNode =rootNode;
         // The first token is empty, the second is the root node
         for(int i =2; i<xpathTokens.length;i++) {

             String axisName = removeNamespace(xpathTokens[i]);


             if (!axisName.startsWith("@")) {

                 NodeList list =currentNode.getChildNodes();

                 Node selectedNode = null;
                 if (!(createMultipleInstances && i==xpathTokens.length-1) ) {
                     // select the last child node only if we need to map to a single cell
                     selectedNode = selectNode(axisName, list);
                 }
                 if (selectedNode==null) {
                     selectedNode = createElement(doc, currentNode, axisName);
                 }
                 currentNode = selectedNode;
             } else {


                 Node attribute = createAttribute(doc, currentNode, axisName);

                 currentNode = attribute;
             }
         }
         return currentNode;
     }

     private Node createAttribute(Document doc, Node currentNode, String axisName) {
         String attributeName = axisName.substring(1);
         NamedNodeMap attributesMap = currentNode.getAttributes();
         Node attribute = attributesMap.getNamedItem(attributeName);
         if (attribute==null) {
             attribute = doc.createAttributeNS("", attributeName);
             attributesMap.setNamedItem(attribute);
         }
         return attribute;
     }

     private Node createElement(Document doc, Node currentNode, String axisName) {
         Node selectedNode;
         if (isNamespaceDeclared()) {
             selectedNode =doc.createElementNS(getNamespace(),axisName);
         } else {
             selectedNode = doc.createElementNS("", axisName);
         }
         currentNode.appendChild(selectedNode);
         return selectedNode;
     }

     private Node selectNode(String axisName, NodeList list) {
         Node selectedNode = null;
         for(int j=0;j<list.getLength();j++) {
             Node node = list.item(j);
             if (node.getNodeName().equals(axisName)) {
                 selectedNode=node;
                 break;
             }
         }
         return selectedNode;
     }


     private boolean isNamespaceDeclared() {
         String schemaNamespace = getNamespace();
         return schemaNamespace!=null && !schemaNamespace.equals("");
     }

     private String getNamespace() {
         return map.getCTSchema().getNamespace();
     }


     /**
      * Compares two xpaths to define an ordering according to the XML Schema
      *
      */
     public int compare(String leftXpath, String rightXpath) {

         int result = 0;
         Node xmlSchema = map.getSchema();


         String[] leftTokens = leftXpath.split("/");
         String[] rightTokens = rightXpath.split("/");

         int minLenght = leftTokens.length< rightTokens.length? leftTokens.length : rightTokens.length;

         Node localComplexTypeRootNode = xmlSchema;


         for(int i =1;i <minLenght; i++) {

             String leftElementName =leftTokens[i];
             String rightElementName = rightTokens[i];

             if (leftElementName.equals(rightElementName)) {


                 Node complexType = getComplexTypeForElement(leftElementName, xmlSchema,localComplexTypeRootNode);
                 localComplexTypeRootNode = complexType;
             } else {
                 int leftIndex = indexOfElementInComplexType(leftElementName,localComplexTypeRootNode);
                 int rightIndex = indexOfElementInComplexType(rightElementName,localComplexTypeRootNode);
                 if (leftIndex!=-1 && rightIndex!=-1) {
                     if ( leftIndex < rightIndex) {
                         result = -1;
                     }if ( leftIndex > rightIndex) {
                         result = 1;
                     }
                 } else {
                     // NOTE: the xpath doesn't match correctly in the schema
                 }
             }
         }

         return result;
     }

     private int indexOfElementInComplexType(String elementName,Node complexType) {

         NodeList list  = complexType.getChildNodes();
         int indexOf = -1;

         for(int i=0; i< list.getLength();i++) {
             Node node = list.item(i);
             if (node instanceof Element) {
                 if (node.getLocalName().equals("element")) {
                     Node nameAttribute  = node.getAttributes().getNamedItem("name");
                     if (nameAttribute.getNodeValue().equals(removeNamespace(elementName))) {
                         indexOf = i;
                         break;
                     }

                 }
             }
         }
         return indexOf;
     }

     private Node getComplexTypeForElement(String elementName,Node xmlSchema,Node localComplexTypeRootNode) {
         String elementNameWithoutNamespace = removeNamespace(elementName);

         String complexTypeName = getComplexTypeNameFromChildren(localComplexTypeRootNode, elementNameWithoutNamespace);

         // Note: we expect that all the complex types are defined at root level
         Node complexTypeNode = null;
         if (!"".equals(complexTypeName)) {
             complexTypeNode = getComplexTypeNodeFromSchemaChildren(xmlSchema, complexTypeNode, complexTypeName);
         }

         return complexTypeNode;
     }

     private String getComplexTypeNameFromChildren(Node localComplexTypeRootNode,
             String elementNameWithoutNamespace) {
         NodeList  list  = localComplexTypeRootNode.getChildNodes();
         String complexTypeName = "";

         for(int i=0; i< list.getLength();i++) {
             Node node = list.item(i);
             if ( node instanceof Element) {
                 if (node.getLocalName().equals("element")) {
                     Node nameAttribute  = node.getAttributes().getNamedItem("name");
                     if (nameAttribute.getNodeValue().equals(elementNameWithoutNamespace)) {
                         Node complexTypeAttribute = node.getAttributes().getNamedItem("type");
                         if (complexTypeAttribute!=null) {
                             complexTypeName = complexTypeAttribute.getNodeValue();
                             break;
                         }
                     }
                 }
             }
         }
         return complexTypeName;
     }

     private Node getComplexTypeNodeFromSchemaChildren(Node xmlSchema, Node complexTypeNode,
             String complexTypeName) {
         NodeList  complexTypeList  = xmlSchema.getChildNodes();
         for(int i=0; i< complexTypeList.getLength();i++) {
             Node node = complexTypeList.item(i);
             if ( node instanceof Element) {
                 if (node.getLocalName().equals("complexType")) {
                     Node nameAttribute  = node.getAttributes().getNamedItem("name");
                     if (nameAttribute.getNodeValue().equals(complexTypeName)) {

                         NodeList complexTypeChildList  =node.getChildNodes();
                         for(int j=0; j<complexTypeChildList.getLength();j++) {
                             Node sequence = complexTypeChildList.item(j);

                             if ( sequence instanceof Element) {
                                 if (sequence.getLocalName().equals("sequence")) {
                                     complexTypeNode = sequence;
                                     break;
                                 }
                             }
                         }
                         if (complexTypeNode!=null) {
                             break;
                         }

                     }
                 }
             }
         }
         return complexTypeNode;
     }
 }
	/* ====================================================================
	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.poi.xssf.extractor;

	import java.io.IOException;
	import java.io.OutputStream;
	import java.util.Collections;
	import java.util.Comparator;
	import java.util.HashMap;
	import java.util.List;
	import java.util.Map;
	import java.util.Vector;

	import javax.xml.parsers.ParserConfigurationException;
	import javax.xml.transform.OutputKeys;
	import javax.xml.transform.Source;
	import javax.xml.transform.Transformer;
	import javax.xml.transform.TransformerException;
	import javax.xml.transform.TransformerFactory;
	import javax.xml.transform.dom.DOMSource;
	import javax.xml.transform.stream.StreamResult;
	import javax.xml.validation.Schema;
	import javax.xml.validation.SchemaFactory;
	import javax.xml.validation.Validator;

	import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
	import org.apache.poi.util.DocumentHelper;
	import org.apache.poi.xssf.usermodel.XSSFCell;
	import org.apache.poi.xssf.usermodel.XSSFMap;
	import org.apache.poi.xssf.usermodel.XSSFRow;
	import org.apache.poi.xssf.usermodel.XSSFSheet;
	import org.apache.poi.xssf.usermodel.XSSFTable;
	import org.apache.poi.xssf.usermodel.helpers.XSSFSingleXmlCell;
	import org.apache.poi.xssf.usermodel.helpers.XSSFXmlColumnPr;
	import org.openxmlformats.schemas.spreadsheetml.x2006.main.STXmlDataType;
	import org.w3c.dom.Document;
	import org.w3c.dom.Element;
	import org.w3c.dom.NamedNodeMap;
	import org.w3c.dom.Node;
	import org.w3c.dom.NodeList;
	import org.xml.sax.SAXException;

	/**
	*
	* Maps an XLSX to an XML according to one of the mapping defined.
	*
	*
	* The output XML Schema must respect this limitations:
	*
	* <ul>
	* <li> all mandatory elements and attributes must be mapped (enable validation to check this)</li>
	*
	* <li> no <any> in complex type/element declaration </li>
	* <li> no <anyAttribute> attributes declaration </li>
	* <li> no recursive structures: recursive structures can't be nested more than one level </li>
	* <li> no abstract elements: abstract complex types can be declared but must not be used in elements. </li>
	* <li> no mixed content: an element can't contain simple text and child element(s) together </li>
	* <li> no <substitutionGroup> in complex type/element declaration </li>
	* </ul>
	*/
	public class XSSFExportToXml implements Comparator<String>{

	private XSSFMap map;

	/**
	* Creates a new exporter and sets the mapping to be used when generating the XML output document
	*
	* @param map the mapping rule to be used
	*/
	public XSSFExportToXml(XSSFMap map) {
	this.map = map;
	}

	/**
	*
	* Exports the data in an XML stream
	*
	* @param os OutputStream in which will contain the output XML
	* @param validate if true, validates the XML againts the XML Schema
	* @throws SAXException
	* @throws TransformerException
	* @throws ParserConfigurationException
	*/
	public void exportToXML(OutputStream os, boolean validate) throws SAXException, ParserConfigurationException, TransformerException {
	exportToXML(os, "UTF-8", validate);
	}

	/**
	* Exports the data in an XML stream
	*
	* @param os OutputStream in which will contain the output XML
	* @param encoding the output charset encoding
	* @param validate if true, validates the XML againts the XML Schema
	* @throws SAXException
	* @throws ParserConfigurationException
	* @throws TransformerException
	* @throws InvalidFormatException
	*/
	public void exportToXML(OutputStream os, String encoding, boolean validate) throws SAXException, ParserConfigurationException, TransformerException{
	List<XSSFSingleXmlCell> singleXMLCells = map.getRelatedSingleXMLCell();
	List<XSSFTable> tables = map.getRelatedTables();

	String rootElement = map.getCtMap().getRootElement();

	Document doc = DocumentHelper.createDocument();

	Element root = null;

	if (isNamespaceDeclared()) {
	root=doc.createElementNS(getNamespace(),rootElement);
	} else {
	root = doc.createElementNS("", rootElement);
	}
	doc.appendChild(root);


	List<String> xpaths = new Vector<String>();
	Map<String,XSSFSingleXmlCell> singleXmlCellsMappings = new HashMap<String,XSSFSingleXmlCell>();
	Map<String,XSSFTable> tableMappings = new HashMap<String,XSSFTable>();

	for(XSSFSingleXmlCell simpleXmlCell : singleXMLCells) {
	xpaths.add(simpleXmlCell.getXpath());
	singleXmlCellsMappings.put(simpleXmlCell.getXpath(), simpleXmlCell);
	}
	for(XSSFTable table : tables) {
	String commonXPath = table.getCommonXpath();
	xpaths.add(commonXPath);
	tableMappings.put(commonXPath, table);
	}


	Collections.sort(xpaths,this);

	for(String xpath : xpaths) {

	XSSFSingleXmlCell simpleXmlCell = singleXmlCellsMappings.get(xpath);
	XSSFTable table = tableMappings.get(xpath);

	if (!xpath.matches(".\\[.")) {

	// Exports elements and attributes mapped with simpleXmlCell
	if (simpleXmlCell!=null) {
	XSSFCell cell = simpleXmlCell.getReferencedCell();
	if (cell!=null) {
	Node currentNode = getNodeByXPath(xpath,doc.getFirstChild(),doc,false);
	STXmlDataType.Enum dataType = simpleXmlCell.getXmlDataType();
	mapCellOnNode(cell,currentNode,dataType);
	}
	}

	// Exports elements and attributes mapped with tables
	if (table!=null) {

	List<XSSFXmlColumnPr> tableColumns = table.getXmlColumnPrs();

	XSSFSheet sheet = table.getXSSFSheet();

	int startRow = table.getStartCellReference().getRow();
	// In mappings created with Microsoft Excel the first row contains the table header and must be skipped
	startRow +=1;

	int endRow = table.getEndCellReference().getRow();

	for(int i = startRow; i<= endRow; i++) {
	XSSFRow row = sheet.getRow(i);

	Node tableRootNode = getNodeByXPath(table.getCommonXpath(),doc.getFirstChild(),doc,true);

	short startColumnIndex = table.getStartCellReference().getCol();
	for(int j = startColumnIndex; j<= table.getEndCellReference().getCol();j++) {
	XSSFCell cell = row.getCell(j);
	if (cell!=null) {
	XSSFXmlColumnPr pointer = tableColumns.get(j-startColumnIndex);
	String localXPath = pointer.getLocalXPath();
	Node currentNode = getNodeByXPath(localXPath,tableRootNode,doc,false);
	STXmlDataType.Enum dataType = pointer.getXmlDataType();


	mapCellOnNode(cell,currentNode,dataType);
	}

	}

	}



	}
	} else {
	// TODO: implement filtering management in xpath
	}
	}

	boolean isValid = true;
	if (validate) {
	isValid =isValid(doc);
	}



	if (isValid) {

	/////////////////
	//Output the XML

	//set up a transformer
	TransformerFactory transfac = TransformerFactory.newInstance();
	Transformer trans = transfac.newTransformer();
	trans.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
	trans.setOutputProperty(OutputKeys.INDENT, "yes");
	trans.setOutputProperty(OutputKeys.ENCODING, encoding);

	//create string from xml tree

	StreamResult result = new StreamResult(os);
	DOMSource source = new DOMSource(doc);
	trans.transform(source, result);

	}
	}


	/**
	* Validate the generated XML against the XML Schema associated with the XSSFMap
	*
	* @param xml the XML to validate
	* @return true, if document is valid
	*/
	private boolean isValid(Document xml) throws SAXException{
	boolean isValid = false;
	try{
	String language = "http://www.w3.org/2001/XMLSchema";
	SchemaFactory factory = SchemaFactory.newInstance(language);

	Source source = new DOMSource(map.getSchema());
	Schema schema = factory.newSchema(source);
	Validator validator = schema.newValidator();
	validator.validate(new DOMSource(xml));
	//if no exceptions where raised, the document is valid
	isValid=true;


	} catch(IOException e) {
	e.printStackTrace();
	}
	return isValid;
	}


	private void mapCellOnNode(XSSFCell cell, Node node, STXmlDataType.Enum outputDataType) {

	String value ="";
	switch (cell.getCellType()) {

	case XSSFCell.CELL_TYPE_STRING: value = cell.getStringCellValue(); break;
	case XSSFCell.CELL_TYPE_BOOLEAN: value += cell.getBooleanCellValue(); break;
	case XSSFCell.CELL_TYPE_ERROR: value = cell.getErrorCellString(); break;
	case XSSFCell.CELL_TYPE_FORMULA: value = cell.getStringCellValue(); break;
	case XSSFCell.CELL_TYPE_NUMERIC: value += cell.getRawValue(); break;
	default: ;

	}
	if (node instanceof Element) {
	Element currentElement = (Element) node;
	currentElement.setTextContent(value);
	} else {
	node.setNodeValue(value);
	}
	}

	private String removeNamespace(String elementName) {
	return elementName.matches(".:.")?elementName.split(":")[1]:elementName;
	}



	private Node getNodeByXPath(String xpath,Node rootNode,Document doc,boolean createMultipleInstances) {
	String[] xpathTokens = xpath.split("/");


	Node currentNode =rootNode;
	// The first token is empty, the second is the root node
	for(int i =2; i<xpathTokens.length;i++) {

	String axisName = removeNamespace(xpathTokens[i]);


	if (!axisName.startsWith("@")) {

	NodeList list =currentNode.getChildNodes();

	Node selectedNode = null;
	if (!(createMultipleInstances && i==xpathTokens.length-1) ) {
	// select the last child node only if we need to map to a single cell
	selectedNode = selectNode(axisName, list);
	}
	if (selectedNode==null) {
	selectedNode = createElement(doc, currentNode, axisName);
	}
	currentNode = selectedNode;
	} else {


	Node attribute = createAttribute(doc, currentNode, axisName);

	currentNode = attribute;
	}
	}
	return currentNode;
	}

	private Node createAttribute(Document doc, Node currentNode, String axisName) {
	String attributeName = axisName.substring(1);
	NamedNodeMap attributesMap = currentNode.getAttributes();
	Node attribute = attributesMap.getNamedItem(attributeName);
	if (attribute==null) {
	attribute = doc.createAttributeNS("", attributeName);
	attributesMap.setNamedItem(attribute);
	}
	return attribute;
	}

	private Node createElement(Document doc, Node currentNode, String axisName) {
	Node selectedNode;
	if (isNamespaceDeclared()) {
	selectedNode =doc.createElementNS(getNamespace(),axisName);
	} else {
	selectedNode = doc.createElementNS("", axisName);
	}
	currentNode.appendChild(selectedNode);
	return selectedNode;
	}

	private Node selectNode(String axisName, NodeList list) {
	Node selectedNode = null;
	for(int j=0;j<list.getLength();j++) {
	Node node = list.item(j);
	if (node.getNodeName().equals(axisName)) {
	selectedNode=node;
	break;
	}
	}
	return selectedNode;
	}


	private boolean isNamespaceDeclared() {
	String schemaNamespace = getNamespace();
	return schemaNamespace!=null && !schemaNamespace.equals("");
	}

	private String getNamespace() {
	return map.getCTSchema().getNamespace();
	}


	/**
	* Compares two xpaths to define an ordering according to the XML Schema
	*
	*/
	public int compare(String leftXpath, String rightXpath) {

	int result = 0;
	Node xmlSchema = map.getSchema();


	String[] leftTokens = leftXpath.split("/");
	String[] rightTokens = rightXpath.split("/");

	int minLenght = leftTokens.length< rightTokens.length? leftTokens.length : rightTokens.length;

	Node localComplexTypeRootNode = xmlSchema;


	for(int i =1;i <minLenght; i++) {

	String leftElementName =leftTokens[i];
	String rightElementName = rightTokens[i];

	if (leftElementName.equals(rightElementName)) {


	Node complexType = getComplexTypeForElement(leftElementName, xmlSchema,localComplexTypeRootNode);
	localComplexTypeRootNode = complexType;
	} else {
	int leftIndex = indexOfElementInComplexType(leftElementName,localComplexTypeRootNode);
	int rightIndex = indexOfElementInComplexType(rightElementName,localComplexTypeRootNode);
	if (leftIndex!=-1 && rightIndex!=-1) {
	if ( leftIndex < rightIndex) {
	result = -1;
	}if ( leftIndex > rightIndex) {
	result = 1;
	}
	} else {
	// NOTE: the xpath doesn't match correctly in the schema
	}
	}
	}

	return result;
	}

	private int indexOfElementInComplexType(String elementName,Node complexType) {

	NodeList list = complexType.getChildNodes();
	int indexOf = -1;

	for(int i=0; i< list.getLength();i++) {
	Node node = list.item(i);
	if (node instanceof Element) {
	if (node.getLocalName().equals("element")) {
	Node nameAttribute = node.getAttributes().getNamedItem("name");
	if (nameAttribute.getNodeValue().equals(removeNamespace(elementName))) {
	indexOf = i;
	break;
	}

	}
	}
	}
	return indexOf;
	}

	private Node getComplexTypeForElement(String elementName,Node xmlSchema,Node localComplexTypeRootNode) {
	String elementNameWithoutNamespace = removeNamespace(elementName);

	String complexTypeName = getComplexTypeNameFromChildren(localComplexTypeRootNode, elementNameWithoutNamespace);

	// Note: we expect that all the complex types are defined at root level
	Node complexTypeNode = null;
	if (!"".equals(complexTypeName)) {
	complexTypeNode = getComplexTypeNodeFromSchemaChildren(xmlSchema, complexTypeNode, complexTypeName);
	}

	return complexTypeNode;
	}

	private String getComplexTypeNameFromChildren(Node localComplexTypeRootNode,
	String elementNameWithoutNamespace) {
	NodeList list = localComplexTypeRootNode.getChildNodes();
	String complexTypeName = "";

	for(int i=0; i< list.getLength();i++) {
	Node node = list.item(i);
	if ( node instanceof Element) {
	if (node.getLocalName().equals("element")) {
	Node nameAttribute = node.getAttributes().getNamedItem("name");
	if (nameAttribute.getNodeValue().equals(elementNameWithoutNamespace)) {
	Node complexTypeAttribute = node.getAttributes().getNamedItem("type");
	if (complexTypeAttribute!=null) {
	complexTypeName = complexTypeAttribute.getNodeValue();
	break;
	}
	}
	}
	}
	}
	return complexTypeName;
	}

	private Node getComplexTypeNodeFromSchemaChildren(Node xmlSchema, Node complexTypeNode,
	String complexTypeName) {
	NodeList complexTypeList = xmlSchema.getChildNodes();
	for(int i=0; i< complexTypeList.getLength();i++) {
	Node node = complexTypeList.item(i);
	if ( node instanceof Element) {
	if (node.getLocalName().equals("complexType")) {
	Node nameAttribute = node.getAttributes().getNamedItem("name");
	if (nameAttribute.getNodeValue().equals(complexTypeName)) {

	NodeList complexTypeChildList =node.getChildNodes();
	for(int j=0; j<complexTypeChildList.getLength();j++) {
	Node sequence = complexTypeChildList.item(j);

	if ( sequence instanceof Element) {
	if (sequence.getLocalName().equals("sequence")) {
	complexTypeNode = sequence;
	break;
	}
	}
	}
	if (complexTypeNode!=null) {
	break;
	}

	}
	}
	}
	}
	return complexTypeNode;
	}
	}