在單個 XML 中解析多個 XPath 表示式
使用與在 XML 文件中評估 NodeList 相同的示例,以下是如何有效地進行多個 XPath 呼叫:
給出以下 XML 文件:
<documentation>
<tags>
<tag name="Java">
<topic name="Regular expressions">
<example>Matching groups</example>
<example>Escaping metacharacters</example>
</topic>
<topic name="Arrays">
<example>Looping over arrays</example>
<example>Converting an array to a list</example>
</topic>
</tag>
<tag name="Android">
<topic name="Building Android projects">
<example>Building an Android application using Gradle</example>
<example>Building an Android application using Maven</example>
</topic>
<topic name="Layout resources">
<example>Including layout resources</example>
<example>Supporting multiple device screens</example>
</topic>
</tag>
</tags>
</documentation>
這是你使用 XPath 評估一個文件中的多個表示式的方法:
XPath xPath = XPathFactory.newInstance().newXPath(); //Make new XPath
DocumentBuilder builder = DocumentBuilderFactory.newInstance();
Document doc = builder.parse(new File("path/to/xml.xml")); //Specify XML file path
NodeList javaExampleNodes = (NodeList) xPath.evaluate("/documentation/tags/tag[@name='Java']//example", doc, XPathConstants.NODESET); //Evaluate the XPath
xPath.reset(); //Resets the xPath so it can be used again
NodeList androidExampleNodes = (NodeList) xPath.evaluate("/documentation/tags/tag[@name='Android']//example", doc, XPathConstants.NODESET); //Evaluate the XPath
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