How to Parsing / Reading XML file in Java?

Sample XML file.

<?xml version="1.0"?>

<students>

    <student>

        <name>John</name>

        <grade>B</grade>

        <age>12</age>

    </student>

    <student>

        <name>Mary</name>

        <grade>A</grade>

        <age>11</age>

    </student>

    <student>

        <name>Simon</name>

        <grade>A</grade>

        <age>18</age>

    </student>

</students>

 

Java code to parse above XML.

package net.viralpatel.java.xmlparser;

 

import java.io.File;

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

 

import org.w3c.dom.Document;

import org.w3c.dom.Element;

import org.w3c.dom.Node;

import org.w3c.dom.NodeList;

 

public class XMLParser {

 

    public void getAllUserNames(String fileName) {

        try {

            DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();

            DocumentBuilder db = dbf.newDocumentBuilder();

            File file = new File(fileName);

            if (file.exists()) {

                Document doc = db.parse(file);

                Element docEle = doc.getDocumentElement();

 

                // Print root element of the document

                System.out.println("Root element of the document: "

                        + docEle.getNodeName());

 

                NodeList studentList = docEle.getElementsByTagName("student");

 

                // Print total student elements in document

                System.out

                        .println("Total students: " + studentList.getLength());

 

                if (studentList != null && studentList.getLength() > 0) {

                    for (int i = 0; i < studentList.getLength(); i++) {

 

                        Node node = studentList.item(i);

 

                        if (node.getNodeType() == Node.ELEMENT_NODE) {

 

                            System.out

                                    .println("=====================");

 

                            Element e = (Element) node;

                            NodeList nodeList = e.getElementsByTagName("name");

                            System.out.println("Name: "

                                    + nodeList.item(0).getChildNodes().item(0)

                                            .getNodeValue());

 

                            nodeList = e.getElementsByTagName("grade");

                            System.out.println("Grade: "

                                    + nodeList.item(0).getChildNodes().item(0)

                                            .getNodeValue());

 

                            nodeList = e.getElementsByTagName("age");

                            System.out.println("Age: "

                                    + nodeList.item(0).getChildNodes().item(0)

                                            .getNodeValue());

                        }

                    }

                } else {

                    System.exit(1);

                }

            }

        } catch (Exception e) {

            System.out.println(e);

        }

    }

    public static void main(String[] args) {

 

        XMLParser parser = new XMLParser();

        parser.getAllUserNames("c:\\test.xml");

    }

}