混合文本和元素节点时XML子节点迭代的问题

Question

我试图解析以下字符串以形成xml文档，然后试图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>

当我试图读取子节点时，它为第一个字符串的TEXT_NODE返回null子，为第二个字符串的ELEMENT_NODE返回null，这是错误的，是API问题吗??

我正在使用以下代码…

        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:: as string

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

期望输出::as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.... 

则输出为"thiswang chu"

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.

希望我讲清楚了。以上代码在Java 6中编译

Answer 1

我假设这是Java。

首先，我很惊讶你的importNode()调用没有得到异常，因为你正在导入Document，这应该是不允许的(根据JavaDoc)。

现在回答您提出的问题:如果您只想附加特定的节点类型，则需要使用节点的类型进行测试。switch语句是最简单的(注意:这还没有编译，可能包含语法错误):

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

Answer 2

可能需要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);

要将dom写入标准输出或文件，可以这样写:

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>