parse xml file in java

input.xml

<?xml version="1.0"?>
<catalog>
   <book id="bk101">
      <author>Gambardella, Matthew</author>
      <title>XML Developer's Guide</title>
      <genre>Computer</genre>
      <price>44.95</price>
      <publish_date>2000-10-01</publish_date>
      <description>An in-depth look at creating applications 
      with XML.</description>
   </book>
   <book id="bk102">
      <author>Ralls, Kim</author>
      <title>Midnight Rain</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2000-12-16</publish_date>
      <description>A former architect battles corporate zombies, 
      an evil sorceress, and her own childhood to become queen 
      of the world.</description>
   </book>
   <book id="bk103">
      <author>Corets, Eva</author>
      <title>Maeve Ascendant</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2000-11-17</publish_date>
      <description>After the collapse of a nanotechnology 
      society in England, the young survivors lay the 
      foundation for a new society.</description>
   </book>
</catalog>

get all leaf nodes from xml file in java:

/**
 * @author lautturi.com
 * Java example:parsing xml file in java
 */

import java.util.*;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathExpression;
import javax.xml.xpath.XPathFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

public class Lautturi {

	public static void main(String[] args) {

		try {
			final Document doc = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse("input.xml");
			final XPathExpression xpath = XPathFactory.newInstance().newXPath().compile("//*[count(./*) = 0]");
			final NodeList nodeList = (NodeList) xpath.evaluate(doc, XPathConstants.NODESET);
			for (int i = 0; i < nodeList.getLength(); i++) {
				final Element el = (Element) nodeList.item(i);
				System.out.println(el.getNodeName());
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

output:

author
title
genre
price
publish_date
description
author
title
genre
price
publish_date
description
author
title
genre
price
publish_date
description