DocumentBuilderDocumentBuilderFactory

Count XML Elements in Java using DOM parser example

In this example we are going to see how to count elements with specific tag names using a DOM parser in Java.

Basically all you have to do in order to count elements in an XML elements is:

  • Open and parse an XML Document using a DocumentBuilder
  • Use Document.getElementsByTagName that will return a list with nodes.
  • Simply print out the length of the above list using getLength method.

Here is the XML file we are going to use as an input:
 
 
testFile.xml:

<?xml version="1.0" encoding="UTF-8" standalone="no"?><company>

	<employee id="10">

		<lastname>Harley</lastname>
        <email>james@example.org</email>
		<department>Human Resources</department>
		<salary>2000000</salary>
	    <address>34 Stanley St.</address>

	</employee>

	<employee id="2">
		<firstname>John</firstname>
		<lastname>May</lastname>
		<email>john@example.org</email>
		<department>Logistics</department>
		<salary>400</salary>
	</employee>

</company>

Let’s take a look at the code:

CountXMLElementJava.java:

package com.javacodegeeks.java.core;

import java.io.IOException;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

public class CountXMLElementJava {

	private static final String xmlfilepath = "C:\\Users\\nikos7\\Desktop\\filesForExamples\\testFile.xml";

	public static void main(String argv[]) {

		try {
			DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();

			DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();

			Document document = documentBuilder.parse(xmlfilepath);

			NodeList nodeList = document.getElementsByTagName("employee");

			System.out.println("Number of elements with tag name employee : " + nodeList.getLength());

		} catch (ParserConfigurationException pce) {
			pce.printStackTrace();
		} catch (IOException ioe) {
			ioe.printStackTrace();
		} catch (SAXException sae) {
			sae.printStackTrace();
		}
	}
}

Output:

Number of elements with tag name employee : 2

Nikos Maravitsas

Nikos has graduated from the Department of Informatics and Telecommunications of The National and Kapodistrian University of Athens. During his studies he discovered his interests about software development and he has successfully completed numerous assignments in a variety of fields. Currently, his main interests are system’s security, parallel systems, artificial intelligence, operating systems, system programming, telecommunications, web applications, human – machine interaction and mobile development.
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