Custom XML import features; tests and implementation

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@799258 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -65,7 +65,7 @@ import org.xml.sax.SAXException;
  * The output XML Schema must respect this limitations:
  * 
  * <ul>
- * <li> all mandatory elements and attributes must be mapped </li>
+ * <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>

src/ooxml/java/org/apache/poi/xssf/extractor/XSSFImportFromXML.java

@@ -0,0 +1,209 @@
+/* ====================================================================
+   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.StringReader;
+import java.util.Iterator;
+import java.util.List;
+import javax.xml.namespace.NamespaceContext;
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.xpath.XPath;
+import javax.xml.xpath.XPathConstants;
+import javax.xml.xpath.XPathExpressionException;
+import javax.xml.xpath.XPathFactory;
+
+import org.apache.poi.util.POILogFactory;
+import org.apache.poi.util.POILogger;
+import org.apache.poi.xssf.model.Table;
+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.helpers.XSSFSingleXmlCell;
+import org.apache.poi.xssf.usermodel.helpers.XSSFXmlColumnPr;
+import org.w3c.dom.Document;
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
+import org.xml.sax.InputSource;
+import org.xml.sax.SAXException;
+
+import com.sun.org.apache.xml.internal.utils.PrefixResolver;
+import com.sun.org.apache.xml.internal.utils.PrefixResolverDefault;
+
+
+/**
+ * 
+ *  Imports data from an external XML to an XLSX to an XML according to one of the mapping 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 
+ *  
+ * 
+ * @author Roberto Manicardi
+ *
+ */
+public class XSSFImportFromXML {
+	
+	private XSSFMap map;
+	
+	private static POILogger logger = POILogFactory.getLogger(XSSFImportFromXML.class);
+	
+	public XSSFImportFromXML(XSSFMap map){
+		
+		this.map = map;
+		
+		
+	}
+	
+	/**
+	 * Imports an XML into the XLSX using the Custom XML mapping defined
+	 * 
+	 * @param xmlInputString the XML to import
+	 * @throws SAXException raised if error occurs during XML parsing
+	 * @throws XPathExpressionException raised if error occurs during XML navigation
+	 */
+	public void importFromXML(String xmlInputString) throws  SAXException, XPathExpressionException{
+		
+		try{
+			
+		DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
+		factory.setNamespaceAware(true); 
+		DocumentBuilder builder = factory.newDocumentBuilder();
+		
+		Document doc = builder.parse(new InputSource(new StringReader(xmlInputString.trim())));
+		
+		List<XSSFSingleXmlCell> singleXmlCells = map.getRelatedSingleXMLCell();
+		
+		List<Table> 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
+		final PrefixResolver resolver = new PrefixResolverDefault(doc.getDocumentElement());
+		
+		NamespaceContext ctx = new NamespaceContext() {
+		
+		       public String getNamespaceURI(String prefix) {
+		              return resolver.getNamespaceForPrefix(prefix);
+		       }
+		       // Dummy implementation - not used!
+		       public Iterator getPrefixes(String val) {
+		    	   return null;
+		       }
+		       // Dummy implemenation - not used!
+		       public String getPrefix(String uri) {
+		    	   return null;
+		       }
+		};
+		xpath.setNamespaceContext(ctx);
+
+
+		
+		
+		for(XSSFSingleXmlCell singleXmlCell :singleXmlCells ){
+		
+			
+			
+			String xpathString = singleXmlCell.getXpath();
+			
+			Node result =  (Node) xpath.evaluate(xpathString,doc, XPathConstants.NODE);		
+			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());
+			cell.setCellValue(textContent);
+			
+			
+			
+			
+		}
+		
+		for(Table table : tables){
+			
+			String commonXPath = table.getCommonXpath();
+		
+			NodeList result =  (NodeList) xpath.evaluate(commonXPath,doc, XPathConstants.NODESET);
+			
+			int rowOffset = table.getStartCellReference().getRow()+1;//the first row contains the table header
+			int columnOffset = table.getStartCellReference().getCol()-1;
+			
+			for(int i = 0; i< result.getLength();i++){
+				
+				// TODO: implement support for denormalized XMLs (see OpenOffice part 4: chapter 3.5.1.7)
+				
+				for(XSSFXmlColumnPr xmlColumnPr: table.getXmlColumnPrs()){
+					
+					int localColumnId = (int)xmlColumnPr.getId();
+					
+					int rowId = rowOffset+i;
+					int columnId = columnOffset+localColumnId;
+					
+					
+					String localXPath = xmlColumnPr.getLocalXPath();
+					localXPath = localXPath.substring(localXPath.substring(1).indexOf('/')+1);
+					
+					// Build an XPath to select the right node (assuming that the commonXPath != "/")
+					String nodeXPath = commonXPath+"["+(i+1)+"]"+localXPath;
+					
+					
+					
+					// TODO: convert the data to the cell format	
+					String value = (String) xpath.evaluate(nodeXPath,result.item(i), XPathConstants.STRING);
+					logger.log(POILogger.DEBUG,"Extracting with xpath "+nodeXPath+" : 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());
+					cell.setCellValue(value.trim());
+					
+				}
+					
+				
+				
+			}
+			
+			
+			
+		}
+		}catch(IOException e){
+			//Thrown by StringReader
+			e.printStackTrace();
+		}catch(ParserConfigurationException e){
+			//Thrown by DocumentBuilderFactory
+			e.printStackTrace();
+		}
+		
+	}
+	
+
+}

src/ooxml/java/org/apache/poi/xssf/model/MapInfo.java

@@ -23,7 +23,6 @@ import java.io.OutputStream;
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
-import java.util.Iterator;
 
 
 import org.apache.poi.POIXMLDocumentPart;
@@ -123,6 +122,19 @@ public class MapInfo extends POIXMLDocumentPart {
 		return maps.get(id);
 	}
 	
+	public XSSFMap getXSSFMapByName(String name){
+		
+		XSSFMap matchedMap = null;
+		
+		for(XSSFMap map :maps.values()){
+			if(map.getCtMap().getName()!=null && map.getCtMap().getName().equals(name)){
+				matchedMap = map;
+			}
+		}		
+		
+		return matchedMap;
+	}
+	
 	/**
 	 * 
 	 * @return all the mappings configured in this document

src/ooxml/java/org/apache/poi/xssf/usermodel/XSSFWorkbook.java

@@ -1297,4 +1297,13 @@ public class XSSFWorkbook extends POIXMLDocument implements Workbook, Iterable<X
     public Collection<XSSFMap> getCustomXMLMappings(){
         return mapInfo == null ? new ArrayList<XSSFMap>() : mapInfo.getAllXSSFMaps();
     }
+    
+    /**
+     * 
+     * @return the helper class used to query the custom XML mapping defined in this workbook
+     */
+    public MapInfo getMapInfo(){
+    	return mapInfo;
+    }
+    
 }

src/ooxml/java/org/apache/poi/xssf/usermodel/helpers/XSSFSingleXmlCell.java

@@ -48,7 +48,7 @@ public class XSSFSingleXmlCell {
 	}
 	
 	/**
-	 * Gets the XSSFCell referenced by the R attribute
+	 * Gets the XSSFCell referenced by the R attribute or creates a new one if cell doesn't exists
 	 * @return the referenced XSSFCell, null if the cell reference is invalid
 	 */
 	public XSSFCell getReferencedCell(){
@@ -58,7 +58,14 @@ public class XSSFSingleXmlCell {
 		CellReference cellReference =  new CellReference(singleXmlCell.getR()); 
 		
 		XSSFRow row = parent.getXSSFSheet().getRow(cellReference.getRow());
+		if(row==null){
+			row = parent.getXSSFSheet().createRow(cellReference.getRow());
+		}
+		
 		cell = row.getCell(cellReference.getCol());  
+		if(cell==null){
+			cell = row.createCell(cellReference.getCol());
+		}
 		
 		
 		return cell;

src/ooxml/java/org/apache/poi/xssf/usermodel/helpers/XSSFXmlColumnPr.java

@@ -47,6 +47,23 @@ public class XSSFXmlColumnPr {
 		return ctXmlColumnPr.getMapId();
 	}
 	
+	public String getXPath(){
+		return ctXmlColumnPr.getXpath();
+	}
+	/**
+	 * (see Open Office XML Part 4: chapter 3.5.1.3)
+	 * @return An integer representing the unique identifier of this column. 
+	 */
+	public long getId(){
+		return ctTableColumn.getId();
+	}
+	
+	
+	/**
+	 * If the XPath is, for example, /Node1/Node2/Node3 and /Node1/Node2 is the common XPath for the table, the local XPath is /Node3
+	 * 	
+	 * @return the local XPath 
+	 */
 	public String getLocalXPath(){
 		String localXPath = "";
 		int numberOfCommonXPathAxis = table.getCommonXpath().split("/").length-1;
@@ -59,7 +76,12 @@ public class XSSFXmlColumnPr {
 	}
 
 	public Enum getXmlDataType() {
+		
 		return ctXmlColumnPr.getXmlDataType();
 	}
+	
+	
+	
+	
 
 }