在Java

Question

<iata:DepartureAirport CodeContext="3"> 
BOM 
</iata:DepartureAirport> 

为aiat显示文本的内容在XML现在：DepartureAirport为元素， 代码上下文属性和 9W为文本，我不能够从XML提取9W， 但只能提取代码上下文值

public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException { 
       tempVal = ""; 
     if(qName.equalsIgnoreCase("iata:Airline")) { 
      //create a new instance of employee 
      tempEmp = new employee(); 
      tempEmp.setType(attributes.getValue("CodeContext")); 
      } 

Answer 1

首先负载使用XML

/** 
    * This method reads in the xmlFile, validates it against the 
    * schemaFile, and if valid, loads it into a WhitespaceFreeXMLDoc 
    * and returns it, which helps because that's a much easier 
    * format for us to deal with. 
    * 
    * @param xmlFile Path and name of xml file to load. 
    * 
    * @param schemaFile Path and name of schema file to use for validation. 
    * 
    * @return A normalized Document object fully loaded with the data found 
    * in the xmlFile. 
    * 
    * @throws InvalidXMLFileFormatException Thrown if the xml file validation fails. 

    */ 
    public Document loadXMLDocument(String xmlFile, String xsdFile) 
      throws InvalidXMLFileFormatException 
    { 
     // FIRST VALIDATE 
     boolean isValid = validateXMLDoc(xmlFile, xsdFile); 
     if (!isValid) 
     { 
      throw new InvalidXMLFileFormatException(xmlFile, xsdFile); 
     } 

     // THIS IS JAVA API STUFF 
     DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 
     try 
     {    
      // FIRST RETRIEVE AND LOAD THE FILE INTO A TREE 
      DocumentBuilder db = dbf.newDocumentBuilder(); 
      Document xmlDoc = db.parse(xmlFile); 
      xmlDoc.getDocumentElement().normalize(); 

      // LET'S RETURN THE DOC 
      return xmlDoc; 
     } 
     // THESE ARE XML-RELATED ERRORS THAT COULD HAPPEN DURING 
     // LOADING AND PARSING IF THE XML FILE IS NOT WELL FORMED 
     // OR IS NOW WHERE AND WHAT WE SAY IT IS 
     catch(ParserConfigurationException | SAXException | IOException pce) 
     { 
      throw new InvalidXMLFileFormatException(xmlFile); 
     }   
    } 

的架构文件具有文档格式的XML后的XML文档，您可以使用此方法

/** 
    * This method extracts the data found in the doc argument that 
    * corresponds to the tagName and returns it as text. If no data 
    * is found, null is returned. Note that this method is only good 
    * for elements that are unique to an XML file, meaning there is only 
    * one of them. 
    * 
    * @param doc Fully-loaded DOM Document corresponding to a loaded 
    * XML file from which we are loading the data. 
    * 
    * @param tagName Name of the tag (i.e. field name) we are looking 
    * to load data for. 
    * 
    * @return The data in the doc that corresponds to the tagName element. 
    * Note that if no data is found, null is returned. 
    */ 
    public String getTextData(Document doc, String tagName) 
    { 
     // IT WAS FOUND, SO GET THE DATA 
     Node node = getNodeWithName(doc, tagName); 
     if (node == null) 
     { 
      return null; 
     } 
     else 
     { 
      String data = node.getTextContent(); 
      return data; 
     } 
    } 

获取特定节点如果你想得到节点本身而不是BOM中的数据

/** 
    * This method can be used to get the node in the document 
    * that is an element of type tagName. null is returned 
    * if none is found. 
    * 
    * @param doc The XML document to search 
    * 
    * @param tagName The name of the XML element/tag to 
    * search for. 
    * 
    * @return The first node found named tagName. If none is 
    * found in the document, null is returned. 
    */ 
    public Node getNodeWithName(Document doc, String tagName) 
    { 
     // GET THE NODE FOR THE tagName ELEMENT 
     NodeList nodeList = doc.getElementsByTagName(tagName); 

     // IF NOT FOUND, DON'T GO ON 
     if (nodeList.getLength() == 0) 
     { 
      return null; 
     } 

     // IT WAS FOUND, SO GET THE DATA 
     Node node = nodeList.item(0); 
     return node; 
    } 

让我知道你有没有在你的XML任何进一步的问题

Answer 2

您将获得characters方法中的值。你必须基本做到如下，

boolean isDepartureAirportElement = false; 
StringBuffer value = new StringBuffer(); 

void startElement(...) { 
    if (qName.equals("iata:DepartureAirport")) { 
     isDepartureAirportElement = true; // set true when your element started 
     String codeContext = attributes.getValue("CodeContext") 
    } 
} 

void characters(char[] buffer, int start, int length) { 
    if (isDepartureAirportElement) { 
     value.append(buffer, start, length); 
    } 
} 

void endElement(...) { 
    if (qName.equals("iata:DepartureAirport")) { 
     isDepartureAirportElement = false; // set false when your element ends 
    } 
} 

它的凌乱使用SAX。我建议使用DOM。但是说，他们有自己的优点和缺点。 DOM比较容易编码，但通常比SAX速度更慢，内存更贵。