XML文件(1)--使用DOM示例

•     其余依赖字段/方法
  

   
   
   
   

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

   
   
   
   
// 书籍列表 private List<Book> bookList = new LinkedList<Book>(); /** * 根据xml文件，获得书籍列表 *  * @param file * @return */ public List<Book> getBookList(String file) { parseXML(file); return bookList; }

• 获取DocumentBuilder(文件解析器)
  

   
   
   
   

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

   
   
   
   
/** * 获取DocumentBuilder对象 *@return  */ private DocumentBuilder getDocumentBuilder() { DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); DocumentBuilder builder = null; try { builder = factory.newDocumentBuilder(); } catch (ParserConfigurationException e) { // TODO Auto-generated catch block e.printStackTrace(); } return builder; }

• 解析XML文件
  

   
   
   
   

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

    
    
    
    

   
   
   
   
 /** * 读取XML，并将book对象存入书籍列表 *  * @param file */ private void parseXML(String file) { // 1.临时书籍变量 Book book; try { // 2.获取DocumentBuilder对象 DocumentBuilder documentBuilder = getDocumentBuilder(); // 3.加载XML文件到当前项目下，获取Document‘文档’对象 Document document = documentBuilder.parse(file); // 4.获取节点名称是book的集合 NodeList books = document.getElementsByTagName("book"); // 5.遍历book节点集合 for (int i = 0; i < books.getLength(); i++) { // 重置book变量 book = new Book(); // 5.1声明book节点变量 Node bookNode = books.item(i); // 5.2获取book节点的属性集合 NamedNodeMap nodeMap = bookNode.getAttributes(); // 5.3遍历属性集合，判断并为book对象的属性赋值 for (int j = 0; j < nodeMap.getLength(); j++) { // 5.4声明book的属性 Node attrNode = nodeMap.item(j); // 5.5若是属性Name为id if (attrNode.getNodeName().equals("id")) { book.setId(Integer.valueOf(attrNode.getNodeValue())); } } // 5.6获取book节点的子节点 NodeList childList = bookNode.getChildNodes(); // 5.7遍历子节点 for (int j = 0; j < childList.getLength(); j++) { // 5.8 声明book子节点 Node child = childList.item(j); // 判断是不是节点。NodeType有三种： // Element(节点)：1，Attribute(属性)：2，#Text(文本)：3。 if (Node.ELEMENT_NODE == child.getNodeType()) { // 5.9使用switch case判断，并为book对象属性赋值 switch (child.getNodeName()) { case "title": book.setTitle(child.getTextContent()); break; case "author": book.setAuthor(child.getTextContent()); break; case "price": book.setPrice(Double.valueOf(child.getTextContent())); break; case "year": book.setYear(child.getTextContent()); break; case "language": book.setLanguage(child.getTextContent()); break; default: System.out.println("未知属性！"); } } } // 6 将book对象放入集合 bookList.add(book); } } catch (SAXException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } }

• 生成XML文件
  

    
    
    
    

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

    
    
    
    
/** * 生成XML文件，写入book列表 *  * @param file */ private void createXML(List<Book> bookList, String file, String encoding) { DocumentBuilder builder = getDocumentBuilder(); //建立document文件 Document document = builder.newDocument(); // 在document中，建立根节点 Element eBookstore = document.createElement("bookstore"); for (Book book : bookList) { // 建立book节点 Element eBook = document.createElement("book"); // 为book节点添加id属性 eBook.setAttribute("id", String.valueOf(book.getId())); // 建立book的子节点 Element eTitle = document.createElement("title"); // 建立CDATA元素 CDATASection titleByCDATA = document.createCDATASection(book.getTitle()); // 将CDATA元素加入title eTitle.appendChild(titleByCDATA); eTitle.setTextContent(book.getTitle()); Element eAuthor = document.createElement("author"); eAuthor.setTextContent(book.getAuthor()); Element eYear = document.createElement("year"); eYear.setTextContent(book.getYear()); Element ePrice = document.createElement("price"); ePrice.setTextContent(String.valueOf(book.getPrice())); Element eLanguage = document.createElement("language"); eLanguage.setTextContent(book.getLanguage()); // 将子节点添加到book中 eBook.appendChild(eTitle); eBook.appendChild(eAuthor); eBook.appendChild(eYear); eBook.appendChild(ePrice); eBook.appendChild(eLanguage); // 将book节点添加到bookstore根节点中 eBookstore.appendChild(eBook); } // 将bookstore节点添加到document中，目前文件只存在与内存中 document.appendChild(eBookstore); // 建立TransformerFactory 对象 Transformer former = getTransformer(encoding); try { // 建立输出流 OutputStream output = new FileOutputStream(file); // 输出XML文件到硬盘 former.transform(new DOMSource(document), new StreamResult(output)); } catch (TransformerConfigurationException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (TransformerException e) { // TODO Auto-generated catch block e.printStackTrace(); } }

• 保存Tranformer对象，用于保存XML文件，设置自动换行和编码
  

    
    
    
    

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

     
     
     
     

    
    
    
    
/** * 获取Tranformer对象 *  * @param encoding * 指定编码 * @return Tranformer */ private Transformer getTransformer(String encoding) { // 建立TransformerFactory 对象 TransformerFactory factory = TransformerFactory.newInstance(); Transformer former = null; try { former = factory.newTransformer(); // 换行 former.setOutputProperty(OutputKeys.INDENT, "yes"); // 指定编码 former.setOutputProperty(OutputKeys.ENCODING, encoding); } catch (TransformerConfigurationException e) { // TODO Auto-generated catch block e.printStackTrace();  } return former; }