混合文本和元素节点时，XML子节点迭代的问题

Question

我试图解析下列字符串以形成一个xml文档，然后尝试提取所有子节点并添加到已经提供给我的不同文档对象。

<dhruba><test>this</test>that<test2>wang chu</test2> something.... </dhruba> 

<dhruba>this is text node <test>this</test>that<test2>wang chu</test2> anything..</dhruba> 

，而我想读的子节点，则返回null孩子TEXT_NODE为1弦和空值ELEMENT_NODE的第二根弦，这是错误的，是API的问题？

我使用下面的代码...它编译，我用java 6

 Node n = null; 
     DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 
       try { 
        db = dbf.newDocumentBuilder(); 
       } catch (ParserConfigurationException e1) { 
        // TODO Auto-generated catch block 
        e1.printStackTrace(); 
       } 
       dom = db.newDocument(); 
       Element rootEle = dom.createElement("resources"); 
     // adding the root element to the document 
     dom.appendChild(rootEle); 

     Element element = dom.createElement("string"); 

     element.setAttribute("name", "some_name"); 
     try { 

      n = db.parse(new InputSource(new StringReader("<dhruba><test>this</test>that<test2>node value</test2> some text</dhruba>"))).getDocumentElement(); 
      n = dom.importNode(n, true); 


      NodeList nodeList = n.getChildNodes(); 
      int length = nodeList.getLength(); 
      System.out.println("Total no of childs : "+length); 
      for(int count = 0 ; count < length ; count++){ 
       Node node = nodeList.item(count); 
       if(node != null){ 
        element.appendChild(node); 
       } 
      } 
     } catch (SAXException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } catch (IOException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 

     rootEle.appendChild(element); 

INPUT ::作为字符串

   <dhruba><string name="some_name"> 
         that 
         <test>this</test>        
         <test2>node value</test2> 
         some text 
        </string> 
       </dhruba> 

预期产出::作为文档

   <string> 
       <string name="some_name"> 
          <test>this</test> 
          <test2>node value</test2> 
       </string> 
       </string> 

如果我试图解析

  <test>this</test>that<test2>wang chu</test2> something.... 

然后输出当属 “thiswang楚”

Why is this happening? what needs to be done if I want to add following node under another document element, i.e. <string>. 
    <test>this</test> 
         that        
         <test2>node value</test2> 
         some text 
[notice that it does not have <dhruba>] inside parent node of another 
document. 

希望我是清楚的。以上代码在Java编译6

Answer 1

也许你想Node.cloneNode()方法：

DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); 
DocumentBuilder db = dbf.newDocumentBuilder(); 

Document dom = db.newDocument(); 

Element element = dom.createElement("string"); 
element.setAttribute("name", "some_name"); 

String inputXMLString = 
    "<dhruba><test>this</test>that<test2>node value</test2> some text</dhruba>"; 
Node n = db.parse(new InputSource(new StringReader(inputXMLString))).getDocumentElement(); 
n = dom.importNode(n, true); 

NodeList nodeList = n.getChildNodes(); 
for (int i = 0; i < nodeList.getLength(); ++i) 
{ 
    Node node = nodeList.item(i); 
    element.appendChild(node.cloneNode(true)); 
} 
dom.appendChild(element); 

要获得dom到标准输出或文件，你可以写：

TransformerFactory tFactory = TransformerFactory.newInstance(); 
Transformer transformer = tFactory.newTransformer(); 
transformer.setOutputProperty(OutputKeys.INDENT, "yes"); 
transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes"); 
DOMSource source = new DOMSource(dom); 
StreamResult result = new StreamResult(System.out); 
transformer.transform(source, result); 

结果：

<string name="some_name"> 
<test>this</test>that<test2>node value</test2> some text</string> 

Answer 2

我会假设这是Java。

首先，我很惊讶你不会因为你的importNode()调用而遇到异常，因为你正在导入Document，这不应该被允许（根据JavaDoc）。

现在您所问的问题是：如果您只想附加特定的节点类型，则需要使用该节点的类型进行测试。一个switch语句是最简单的（注意：这还没有被编译，可能含有语法错误）：

switch (n.getNodeType()) 
{ 
    case ELEMENT_NODE : 
     // append the node to the other tree 
     break; 
    default : 
     // do nothing 
}