Use dom4j parse, create, modify xml documentation

• 1, parse and traverse the xml document

 public void parseXml() throws DocumentException {
    //获取解析器
    SAXReader reader = new SAXReader();
    //读取xml文件
    InputStream inputStream = MyBeanFactoryXml.class.getClassLoader().getResourceAsStream("bean.xml");
    Document document = reader.read(inputStream);
    //从根节点开始遍历
    Element rootElement = document.getRootElement();
    //获取根节点下所有元素
    Iterator iterator = rootElement.elementIterator();
    //遍历根节点
    while (iterator.hasNext()) {
        Element element = (Element) iterator.next();
        Attribute id = element.attribute("id");
        String value = id.getValue();
        System.out.println(value);
    }
}

• 2, create xml document

   public void createXml() throws IOException {
   //创建xml对象
   Document document = DocumentHelper.createDocument();
   //设置根节点
   Element root = DocumentHelper.createElement("beans");
   document.setRootElement(root);
   //设置子节点
   root.addElement("bean")
           .addAttribute("id", "userDao")
           .addText("this is a userDao");
   root.addElement("bean")
           .addAttribute("id", "userService")
           .addText("this is a userService");
   //输出文档
   FileWriter out=new FileWriter("test.xml");
   //美化格式
   OutputFormat format=OutputFormat.createPrettyPrint();
   XMLWriter xmlWriter=new XMLWriter(out,format);
   xmlWriter.write(document);
   xmlWriter.close();
  

  }

• 3, modify the xml document and write-back

   public void modifyXml() throws DocumentException, IOException {
   //获取解析器
   SAXReader reader = new SAXReader();
   //读取xml文件
   InputStream inputStream = MyBeanFactoryXml.class.getClassLoader().getResourceAsStream("bean.xml");
   Document document = reader.read(inputStream);
   //从根节点开始遍历
   Element rootElement = document.getRootElement();
   //获取根节点下所有元素
   Iterator iterator = rootElement.elementIterator();
   //遍历根节点
   while (iterator.hasNext()) {
       Element element = (Element) iterator.next();
       Attribute id = element.attribute("id");
       String value = id.getValue();
       if(value.equals("userDao")){
           element.addAttribute("id", "myDao");
           String path = MyBeanFactoryXml.class.getClassLoader().getResource("bean.xml").getPath();
           FileWriter out=new FileWriter(path);
           OutputFormat format=OutputFormat.createPrettyPrint();
           XMLWriter xmlWriter=new XMLWriter(out,format);
           xmlWriter.write(document);
           xmlWriter.close();
       }
   }