Using following-sibling in XPath
In this part of tutorial we are going to describe you
how one can use "following-sibling" axis in to the XPath
expression. "following-sibling" has some other working rather
than "following" axis because it selects all siblings following
the
context node.
In this example also we have created an XML file "persons.xml"
as in our previous section, which is necessary to execute XPath query or
expression on
to it. This "persons.xml" contains information related to name,
age, gender of different persons.
Here is the full source code for persons.xml file
as follows :
persons.xml
<?xml version="1.0" ?>
<information>
<person id="1">
<name>Deep</name>
<age>34</age>
<gender>Male</gender>
</person>
<person id="2">
<name>Kumar</name>
<age>24</age>
<gender>Male</gender>
</person>
<person id="3">
<name>Deepali</name>
<age>19</age>
<gender>Female</gender>
</person>
<!-- more persons... -->
</information> |
Now we have declared a class XPathFollowSibling class
and
in this class we are parsing the XML file with JAXP. First of all we need
to load the document into DOM Document object. We have put that
persons.xml file in that current working directory. For downloading document
we have created a new instance of DocumentBuilderFactory and then this
instance is further going to be used in creating an object of DocumentBuilder.
DocumentBuilderFactory domFactory =
DocumentBuilderFactory.newInstance();
domFactory.setNamespaceAware(true);
DocumentBuilder builder = domFactory.newDocumentBuilder();
Document doc = builder.parse("persons.xml"); |
Above lines of code parses "persons.xml"
file and creates a Document object. Next we have created XPath object
with the use of XPathFactory.
XPath xpath = XPathFactory.newInstance().newXPath(); |
"setNamespaceAware()" tells that the
parser produced by this code will provide full support for XML namespaces.
Expression "//following-sibling::*" will
select all the following sibling of root node "information".
Here is the example code for XPathFollowSibling.java
as follows:
XPathFollowSibling.java
import org.w3c.dom.*;
import javax.xml.xpath.*;
import javax.xml.parsers.*;
import java.io.IOException;
import org.xml.sax.SAXException;
public class XPathFollowSibling {
public static void main(String[] args)
throws ParserConfigurationException, SAXException,
IOException, XPathExpressionException {
DocumentBuilderFactory domFactory =
DocumentBuilderFactory.newInstance();
domFactory.setNamespaceAware(true);
DocumentBuilder builder = domFactory.newDocumentBuilder();
Document doc = builder.parse("persons.xml");
XPath xpath = XPathFactory.newInstance().newXPath();
XPathExpression expr = xpath.compile("//following-sibling::*");
// Selecting all element's following-sibling name
Object result = expr.evaluate(doc, XPathConstants.NODESET);
NodeList nodes = (NodeList) result;
for (int i = 0; i < nodes.getLength(); i++) {
System.out.println(nodes.item(i).getNodeName());
}
expr = xpath.compile("//following-sibling::person/*/text()");
// Selecting all person element's following-sibling value
result = expr.evaluate(doc, XPathConstants.NODESET);
nodes = (NodeList) result;
for (int i = 0; i < nodes.getLength(); i++) {
System.out.print(nodes.item(i).getNodeValue()+", ");
}
}
}
|
Output:
Download Source Code
|
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