I have an XML file and I hant to get the data from it by using SAX. It goes till startElement() where it gets an error because when I try to get the attributes value, these are null. Why?
First of all, I call this method: load()
public RealEstate load() { RealEstate data = null; try { //Create a "parser factory" for creating SAX parsers SAXParserFactory spfac = SAXParserFactory.newInstance(); //Now use the parser factory to create a SAXParser object SAXParser sp = spfac.newSAXParser(); XMLReader xmlReader = sp.getXMLReader(); //Create an instance of this class; it defines all the handler methods SaxParserRealEstateHandler handler = new SaxParserRealEstateHandler(); //assign our handler xmlReader.setContentHandler(handler); // Convert file to URL. URL url = handler.fileToURL(new File(xmlFilename)); // Parse file. xmlReader.parse(url.toString()); data = handler.getData(); } catch (ParserConfigurationException ex) { Logger.getLogger(RealStatePersistXML.class.getName()).log(Level.SEVERE, null, ex); } catch (SAXException ex) { Logger.getLogger(RealStatePersistXML.class.getName()).log(Level.SEVERE, null, ex); } catch (IOException ex) { Logger.getLogger(RealStatePersistXML.class.getName()).log(Level.SEVERE, null, ex); } return data; } Here I have the methods startElement and endElement.
class SaxParserRealEstateHandler extends DefaultHandler { private String temp; private RealEstate data; private Estate estate; private estateAddress address; /** * CONSTRUCTOR */ public SaxParserRealEstateHandler() { } /** * getData() * This method gets the list of estates from RealEstate class. * @return data list of states. Null in case of error or list not found. */ public RealEstate getData() { // RealEstate data = new RealEstate(); // data.addEstate(estate); // data.getEstates(); // return data; } /* * When the parser encounters plain text (not XML elements), * it calls(this method, which accumulates them in a string buffer */ public void characters(char[] buffer, int start, int length) { temp = new String(buffer, start, length); } /* * Every time the parser encounters the beginning of a new element, * it calls this method, which resets the string buffer */ public void startElement(String uri, String localName, String qName, Attributes attributes){ switch (qName){ case"realState": data = new RealEstate(); break; case"estate": estate = new Estate(); estate.setType(attributes.getValue("type")); estate.setSurface(Double.parseDouble(attributes.getValue("surface"))); //estate.setAddress(attributes.getValue("address")); estate.setPrice(Integer.parseInt(attributes.getValue("price"))); break; case"address": address = new estateAddress(); address.setStreet(attributes.getValue("type")); address.setNumber(Integer.parseInt(attributes.getValue("surface"))); address.setFloor(Integer.parseInt(attributes.getValue("type"))); address.setDoor(Integer.parseInt(attributes.getValue("surface"))); break; default: break; } } public void endElement(String uri, String localName, String qName, Attributes attributes) throws SAXException { switch (qName){ case"estate": data.getEstates().add(estate);//quant ha llegit la etiqueta (</estate>) l'agreguem break; case"surface": double surface = Double.parseDouble(temp); estate.setSurface(surface); break; case"price": double price = Double.parseDouble(temp);//tractar tema errors del parseDouble! estate.setPrice(price); break; case"address": estate.setAddress(address); break; case"street": address.setStreet(temp); break; case"number": int number = Integer.parseInt(temp); address.setNumber(number); break; case"floor": address.setStreet(temp); break; case"door": address.setStreet(temp); break; default: break; } } /** fileToURL() * Convenience method to convert a file to a url * @throws Error if malformed url exception is generated */ public URL fileToURL(File file) { String path = file.getAbsolutePath(); String fSep = System.getProperty("file.separator"); if (fSep != null && fSep.length() == 1) path = path.replace(fSep.charAt(0), '/'); if (path.length() > 0 && path.charAt(0) != '/') path = '/' + path; try { return new URL("file", null, path); } catch (java.net.MalformedURLException e) { throw new Error("Unexpected MalformedURLException");//no he pogut muntar una url com deu mana //retornar null } } } XML code
<?xml version="1.0" encoding="UTF-8"?> <realState xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="realState.xsd"> <estate> <type>House</type> <surface>250,0</surface> <address> <street>C/Tarragona</street> <number>54</number> <floor>2</floor> <door>1</door> </address> <price>140000,0</price> </estate> </realState> XSD code: http://pastebin.com/nzEDsdLg
Classes RealEstate and Estate are working ok!
Thank you!
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