java - 使用 xpath 更新 xml 文档

Question

您好，这是我的 xml 文档:

<city> 
  <beirut> 
    <restaurant> 
      <name>sada</name> 
    </restaurant> 
  </beirut>  
  <jbeil> 
    <restaurant> 
      <name>toto</name>  
      <rating>4.3/5</rating> 
    </restaurant>  
    <restaurant> 
      <name>jojo</name>  
      <rating>4.3/5</rating> 
    </restaurant> 
  </jbeil>  
  <sour> 
    <restaurant> 
      <name>sada</name> 
    </restaurant> 
  </sour> 
</city>

我想使用 xpath 和 netbeans 将 jbeil 的“jojo”餐厅的评级从 4.3/5 更新到 4.5/5，请帮忙，

此代码给出评级，

  try {
     File inputFile = new File("src/xpath/josephXml.xml");
     DocumentBuilderFactory dbFactory 
        = DocumentBuilderFactory.newInstance();
     DocumentBuilder dBuilder;

     dBuilder = dbFactory.newDocumentBuilder();

     Document doc = dBuilder.parse(inputFile);
     doc.getDocumentElement().normalize();

     XPath xPath =  XPathFactory.newInstance().newXPath();

     String expression = "/City/Jbeil/Restaurant";          
     NodeList nodeList = (NodeList) xPath.compile(expression).evaluate(doc, XPathConstants.NODESET);
     for (int i = 0; i < nodeList.getLength(); i++) {
        Node nNode = nodeList.item(i);
        System.out.println("\nCurrent Element :" 
           + nNode.getNodeName());
        if (nNode.getNodeType() == Node.ELEMENT_NODE) {
           Element eElement = (Element) nNode;

           System.out.println("rating : " 
              + eElement
                 .getElementsByTagName("rating")
                 .item(0)
                 .getTextContent());

我只想更新 jbeil 名称为“jojo”的餐厅的评级，请帮忙

Answer 1

这是一种可能的 XPath，用于在 jbeil 市查找名为 jojo 的餐厅，然后返回相应的 rating 元素:

/city/jbeil/restaurant[name='jojo']/rating

请注意，XML 和 XPath 区分大小写，因此我在上面的 XPath 中使用了所有小写字符来匹配此问题中发布的 XML。

我对 Java 不太了解，但通过互联网*快速搜索得出这样的结果:

XPath xpath = XPathFactory.newInstance().newXPath();
String expression = "/city/jbeil/restaurant[name='jojo']/rating"; 
Element e = (Element)xpath.evaluate(expression, doc, XPathConstant.NODE);
if (e != null)
  e.setTextContent("4.5/5");

*) how to modify xml tag specific value in java?