http://poi.apache.org/: Apache POI - Java API To Access Microsoft Format Files (Apache Software Foundation) 
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   this work for additional information regarding copyright ownership.
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   distributed under the License is distributed on an "AS IS" BASIS,
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package org.apache.poi.xssf.extractor;

import java.io.IOException;
import java.io.StringReader;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Date;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

import javax.xml.namespace.NamespaceContext;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpressionException;
import javax.xml.xpath.XPathFactory;

import org.apache.poi.ss.usermodel.DateUtil;
import org.apache.poi.ss.util.CellReference;
import org.apache.poi.ooxml.util.DocumentHelper;
import org.apache.poi.util.LocaleUtil;
import org.apache.poi.util.POILogFactory;
import org.apache.poi.util.POILogger;
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.XSSFTable;
import org.apache.poi.xssf.usermodel.XSSFTableColumn;
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.InputSource;
import org.xml.sax.SAXException;


Imports data from an external XML to an XLSX according to one of the mappings
defined.The output XML Schema must respect this limitations:

    

  • the input XML must be valid according to the XML Schema used in the mapping
    • 

  • denormalized table mapping is not supported (see OpenOffice part 4: chapter 3.5.1.7)
    • 

  • all the namespaces used in the document must be declared in the root node
    • 



/**
 * Imports data from an external XML to an XLSX according to one of the mappings
 * defined.The output XML Schema must respect this limitations:
 * <ul>
 * <li>the input XML must be valid according to the XML Schema used in the mapping</li>
 * <li>denormalized table mapping is not supported (see OpenOffice part 4: chapter 3.5.1.7)</li>
 * <li>all the namespaces used in the document must be declared in the root node</li>
 * </ul>
 */
public class XSSFImportFromXML {

    private final XSSFMap _map;

    private static final POILogger logger = POILogFactory.getLogger(XSSFImportFromXML.class);

    public XSSFImportFromXML(XSSFMap map) {
        _map = map;
    }

    
Imports an XML into the XLSX using the Custom XML mapping defined

Params:
  • xmlInputString – the XML to import
Throws:
/**
     * Imports an XML into the XLSX using the Custom XML mapping defined
     *
     * @param xmlInputString the XML to import
     * @throws SAXException if error occurs during XML parsing
     * @throws XPathExpressionException if error occurs during XML navigation
     * @throws IOException  if there are problems reading the input string
     */
    public void importFromXML(String xmlInputString) throws SAXException, XPathExpressionException, IOException {

        DocumentBuilder builder = DocumentHelper.newDocumentBuilder();

        Document doc = builder.parse(new InputSource(new StringReader(xmlInputString.trim())));

        List<XSSFSingleXmlCell> singleXmlCells = _map.getRelatedSingleXMLCell();

        List<XSSFTable> tables = _map.getRelatedTables();

        XPathFactory xpathFactory = XPathFactory.newInstance();
        XPath xpath = xpathFactory.newXPath();

        // Setting namespace context to XPath
        // Assuming that the namespace prefix in the mapping xpath is the
        // same as the one used in the document
        xpath.setNamespaceContext(new DefaultNamespaceContext(doc));

        for (XSSFSingleXmlCell singleXmlCell : singleXmlCells) {

            STXmlDataType.Enum xmlDataType = singleXmlCell.getXmlDataType();
            String xpathString = singleXmlCell.getXpath();
            Node result = (Node) xpath.evaluate(xpathString, doc, XPathConstants.NODE);
            // result can be null if value is optional (xsd:minOccurs=0), see bugzilla 55864
            if (result != null) {
                String textContent = result.getTextContent();
                logger.log(POILogger.DEBUG, "Extracting with xpath " + xpathString + " : value is '" + textContent + "'");
                XSSFCell cell = singleXmlCell.getReferencedCell();
                logger.log(POILogger.DEBUG, "Setting '" + textContent + "' to cell " + cell.getColumnIndex() + "-" + cell.getRowIndex() + " in sheet "
                                                + cell.getSheet().getSheetName());
                setCellValue(textContent, cell, xmlDataType);
            }
        }

        for (XSSFTable table : tables) {

            String commonXPath = table.getCommonXpath();
            NodeList result = (NodeList) xpath.evaluate(commonXPath, doc, XPathConstants.NODESET);
            int rowOffset = table.getStartCellReference().getRow() + table.getHeaderRowCount();
            int columnOffset = table.getStartCellReference().getCol();

            table.setDataRowCount(result.getLength());

            for (int i = 0; i < result.getLength(); i++) {

                // TODO: implement support for denormalized XMLs (see
                // OpenOffice part 4: chapter 3.5.1.7)

                Node singleNode = result.item(i).cloneNode(true);

                for (XSSFTableColumn tableColumn : table.getColumns()) {

                    XSSFXmlColumnPr xmlColumnPr = tableColumn.getXmlColumnPr();
                    if(xmlColumnPr == null) {
                        continue;
                    }

                    int rowId = rowOffset + i;
                    int columnId = columnOffset + tableColumn.getColumnIndex();
                    String localXPath = xmlColumnPr.getLocalXPath();
                    localXPath = localXPath.substring(localXPath.indexOf('/', 1) + 1);

                    // TODO: convert the data to the cell format
                    String value = (String) xpath.evaluate(localXPath, singleNode, XPathConstants.STRING);
                    logger.log(POILogger.DEBUG, "Extracting with xpath " + localXPath + " : value is '" + value + "'");
                    XSSFRow row = table.getXSSFSheet().getRow(rowId);
                    if (row == null) {
                        row = table.getXSSFSheet().createRow(rowId);
                    }

                    XSSFCell cell = row.getCell(columnId);
                    if (cell == null) {
                        cell = row.createCell(columnId);
                    }
                    logger.log(POILogger.DEBUG, "Setting '" + value + "' to cell " + cell.getColumnIndex() + "-" + cell.getRowIndex() + " in sheet "
                                                    + table.getXSSFSheet().getSheetName());
                    setCellValue(value, cell, xmlColumnPr.getXmlDataType());
                }
            }
        }
    }

    

    private static enum DataType {
        BOOLEAN(STXmlDataType.BOOLEAN), //
        DOUBLE(STXmlDataType.DOUBLE), //
        INTEGER(STXmlDataType.INT, STXmlDataType.UNSIGNED_INT, STXmlDataType.INTEGER), //
        STRING(STXmlDataType.STRING), //
        DATE(STXmlDataType.DATE);

        private Set<STXmlDataType.Enum> xmlDataTypes;

        private DataType(STXmlDataType.Enum... xmlDataTypes) {
            this.xmlDataTypes = new HashSet<>(Arrays.asList(xmlDataTypes));
        }

        public static DataType getDataType(STXmlDataType.Enum xmlDataType) {
            for (DataType dataType : DataType.values()) {
                if (dataType.xmlDataTypes.contains(xmlDataType)) {
                    return dataType;
                }
            }
            return null;
        }
    }

    private void setCellValue(String value, XSSFCell cell, STXmlDataType.Enum xmlDataType) {
        DataType type = DataType.getDataType(xmlDataType);
        try {
            if (value.isEmpty() || type == null) {
                cell.setCellValue((String) null);
            } else {
                switch (type) {
                case BOOLEAN:
                    cell.setCellValue(Boolean.parseBoolean(value));
                    break;
                case DOUBLE:
                    cell.setCellValue(Double.parseDouble(value));
                    break;
                case INTEGER:
                    cell.setCellValue(Integer.parseInt(value));
                    break;
                case DATE:
                    DateFormat sdf = new SimpleDateFormat("yyyy-MM-dd", LocaleUtil.getUserLocale());
                    Date date = sdf.parse(value);
                    cell.setCellValue(date);
                    if (!DateUtil.isValidExcelDate(cell.getNumericCellValue())) {
                        cell.setCellValue(value);
                    }
                    break;
                case STRING:
                default:
                    cell.setCellValue(value.trim());
                    break;
                }
            }
        } catch (IllegalArgumentException | ParseException e) {
            throw new IllegalArgumentException(String.format(LocaleUtil.getUserLocale(), "Unable to format value '%s' as %s for cell %s", value,
                    type, new CellReference(cell).formatAsString()));
        }
    }

    private static final class DefaultNamespaceContext implements NamespaceContext {
        
Node from which to start searching for a xmlns attribute that binds a
prefix to a namespace.

/**
         * Node from which to start searching for a xmlns attribute that binds a
         * prefix to a namespace.
         */
        private final Element _docElem;

        public DefaultNamespaceContext(Document doc) {
            _docElem = doc.getDocumentElement();
        }

        @Override
        public String getNamespaceURI(String prefix) {
            return getNamespaceForPrefix(prefix);
        }

        
Params:
  • prefix – Prefix to resolve.
Returns:uri of Namespace that prefix resolves to, or
        null if specified prefix is not bound.
/**
         * @param prefix Prefix to resolve.
         * @return uri of Namespace that prefix resolves to, or
         *         <code>null</code> if specified prefix is not bound.
         */
        private String getNamespaceForPrefix(String prefix) {

            // Code adapted from Xalan's org.apache.xml.utils.PrefixResolverDefault.getNamespaceForPrefix()

            if (prefix.equals("xml")) {
                return "http://www.w3.org/XML/1998/namespace";
            }

            Node parent = _docElem;

            while (parent != null) {

                int type = parent.getNodeType();
                if (type == Node.ELEMENT_NODE) {
                    if (parent.getNodeName().startsWith(prefix + ":")) {
                        return parent.getNamespaceURI();
                    }
                    NamedNodeMap nnm = parent.getAttributes();

                    for (int i = 0; i < nnm.getLength(); i++) {
                        Node attr = nnm.item(i);
                        String aname = attr.getNodeName();
                        boolean isPrefix = aname.startsWith("xmlns:");

                        if (isPrefix || aname.equals("xmlns")) {
                            int index = aname.indexOf(':');
                            String p = isPrefix ? aname.substring(index + 1) : "";

                            if (p.equals(prefix)) {
                                return attr.getNodeValue();
                            }
                        }
                    }
                } else if (type == Node.ENTITY_REFERENCE_NODE) {
                    continue;
                } else {
                    break;
                }
                parent = parent.getParentNode();
            }

            return null;
        }

        // Dummy implementation - not used!
        @Override
        public Iterator<String> getPrefixes(String val) {
            return null;
        }

        // Dummy implementation - not used!
        @Override
        public String getPrefix(String uri) {
            return null;
        }
    }
}