Java Language XML XPath Evaluation Parsing multiple XPath Expressions in a single XML
Example
Using the same example as Evaluating a NodeList in an XML document, here is how you would make multiple XPath calls efficiently:
Given the following XML document:
<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>
This is how you would use XPath to evaluate multiple expressions in one document:
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
...
