Question

我在STAX java中需要指导我有xml文件，我需要在满足前一个父节点book id属性值之前获取内部元素值。例如。

<books>
<book id = "1">
   <chap num ="1"> This First Title </chap>
   <chap num ="2"> This second of first book </chap>
</book>
<book id = "2">
   <chap num ="1"> This First Title of second book </chap>
   <chap num = "2"> This Second of second book </chap>
</book>
</books>

我需要基于书籍属性id的比较，来自“chap”元素的属性值。

只是提示会引导我。

Answer 1

你需要沿着这些方向做点什么

String xmlString = ...
DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
Document doc = docBuilder.parse(xmlString);

XPathFactory xPathfactory = XPathFactory.newInstance();
XPath xpath = xPathfactory.newXPath();
String xpathExp = "/books/book[@id=\"2\"]";
Node node = (Node) xpath.evaluate(xpathExp, doc, XPathConstants.NODE);

来自＆＃34;书＆＃34;你可以循环遍历子节点（＆＃34; chap＆＃34;节点）。或者，您可以通过以下方式直接访问子节点列表：

String xpathExp = "/books/book[@id=\"2\"]/chap";
NodeList chapNodeList = (NodeList) xpath.evaluate(xpathExp, doc, XPathConstants.NODESET);

然后，您可以从＆＃34; chap＆＃34;中检索属性值。节点。（例如，node.getTextContent();）

或者，如果您知道所需的章节，请将xpath表达式修改为更具体。

如何获取属性stax Java上的子节点值

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