XPath get attribute value example
Continuing on our previous example on how to search for a text using XPath
, we shall demonstrate how to get an attribute value from an XPath Node
.
As we already know, the @
attribute is used to denote an attribute in the XPathExpression
. So we shall use extract the attribute value by specifying the node selector in the expression.
In the example, the name of the cricketer is known. We have to determine the handedness of the cricketer, which is mentioned in the type attribute of the XPath.
cricketTeam_info.xml:
<?xml version="1.0" encoding="UTF-8"?> <cricketers> <cricketer type="righty"> <name>MS Dhoni</name> <role>Captain</role> <position>Wicket-Keeper</position> </cricketer> <cricketer type="lefty"> <name>Shikhar Dhawan</name> <role>Batsman</role> <position>Point</position> </cricketer> <cricketer type="righty"> <name>Virat Kohli</name> <role>Batsman</role> <position>cover</position> </cricketer> <cricketer type="righty"> <name>Shami</name> <role>Bowler</role> <position>SquareLeg</position> </cricketer> <cricketer type="lefty"> <name>Zaheer Khan</name> <role>Bowler</role> <position>FineLeg</position> </cricketer> </cricketers>
ExtractXPathAttribute.java:
package com.jcg; import javax.xml.parsers.DocumentBuilder; import javax.xml.parsers.DocumentBuilderFactory; import javax.xml.xpath.XPath; import javax.xml.xpath.XPathConstants; import javax.xml.xpath.XPathExpression; import javax.xml.xpath.XPathFactory; import org.w3c.dom.Document; import org.w3c.dom.NodeList; public class ExtractXPathAttribute { public static void main(String[] args) throws Exception { DocumentBuilderFactory documentumentBuilderFactory = DocumentBuilderFactory.newInstance(); documentumentBuilderFactory.setNamespaceAware(true); DocumentBuilder documentumentBuilder = documentumentBuilderFactory.newDocumentBuilder(); Document document = documentumentBuilder.parse("src/cricketTeam_info.xml"); XPathFactory xpathFactory = XPathFactory.newInstance(); XPath xpath = xpathFactory.newXPath(); // get the type attribute of cricketer with name = 'Shami' XPathExpression expr = xpath.compile("//cricketer[name='Shami']/@type"); String names = (String) expr.evaluate(document, XPathConstants.STRING); System.out.println("Righty attribute is : " + names); //get the type attribute of cricketers with role = 'Bowler' expr = xpath.compile("//cricketer[role='Bowler']/@type"); NodeList nodes = (NodeList) expr.evaluate(document, XPathConstants.NODESET); for (int i = 0; i < nodes.getLength(); i++) System.out.println("Righty attribute is : " + nodes.item(i).getNodeValue()); } }
OUTPUT:
The type of cricketer with name Shami is : righty Bowler Attribute is : lefty Bowler Attribute is : righty
In the first case we query the XPath using the name of the cricketer and the return type is XPathConstants.STRING
. In the second case, we query the XML document for all the cricketers in the role of "BOWLER"
for their handedness type. We extract the XPathConstants.NODESET
and iterate over it to get the results.
Conclusion
Here we studied, how we can extract the attribute value from an XPath node.
You can download the source code of this example here: ExtractXPathAttributeDemo.zip