Read xml file in java using DOM parser

How to read XML file in Java Using DOM Parser

In this article, we will learn how to read XML file in java using DOM Parser.

DOM stands for Document Object Model.

DOM parser parses the entire XML file, loads it into memory and then models it into a tree structure with each element representing tree branches.

Note:- DOM Parser is slow when XML document contains lot of data because it loads entire file into memory. Consider using SAX Parser when file size is high.

Note :- In Programs, consider changing xmlFile with your system’s file path.

1. Java Program of DOM XML Parser

In this example we will get the node by “name” and display the value.


<?xml version="1.0"?>

<contactbook>
	<employee id="101">
		<name>Devil Donald</name>
		<email>donald.devil@abcd.com</email>
		<phone>+91 9090909090</phone>
	</employee>

	<employee id="201">
		<name>Nevil Ray</name>
		<email>ray.nevil@abcd.com</email>
		<phone>+1 919191919</phone>
	</employee>
</contactbook>

<?xml version="1.0"?>

<name>Devil Donald</name>

<email>donald.devil@abcd.com</email>

</employee>

<name>Nevil Ray</name>

<email>ray.nevil@abcd.com</email>

</employee>

</contactbook>


package com.codenuclear;

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 ReadXMLUsingDOM {

	public static void main(String args[]) {

	    try {

		File xmlFile = new File("D:\\Files\\contactbook.xml");
		DocumentBuilderFactory docbuildFactory = DocumentBuilderFactory.newInstance();
		DocumentBuilder docBuilder = docbuildFactory.newDocumentBuilder();
		Document document = docBuilder.parse(xmlFile);

		document.getDocumentElement().normalize();

		System.out.println("Root element name :- " + document.getDocumentElement().getNodeName());

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

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

			Node node = nodeList.item(i);

			System.out.println("\nCurrent element name :- " + node.getNodeName());
			System.out.println("-------------------------------------");

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

				Element element = (Element) node;

				System.out.println("Employee id :- " + element.getAttribute("id"));
				System.out.println("Employee Name : " + element.getElementsByTagName("name").item(0).getTextContent());
				System.out.println("Email: " + element.getElementsByTagName("email").item(0).getTextContent());
				System.out.println("Phone: " + element.getElementsByTagName("phone").item(0).getTextContent());
				
			}
		}
	    } catch (Exception e) {
		e.printStackTrace();
	    }
	  }
	
}

package com.codenuclear;

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 ReadXMLUsingDOM {

public static void main(String args[]) {

try {

File xmlFile = new File("D:\\Files\\contactbook.xml");

DocumentBuilderFactory docbuildFactory = DocumentBuilderFactory.newInstance();

DocumentBuilder docBuilder = docbuildFactory.newDocumentBuilder();

Document document = docBuilder.parse(xmlFile);

document.getDocumentElement().normalize();

System.out.println("Root element name :- " + document.getDocumentElement().getNodeName());

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

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

Node node = nodeList.item(i);

System.out.println("\nCurrent element name :- " + node.getNodeName());

System.out.println("-------------------------------------");

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

Element element = (Element) node;

System.out.println("Employee id :- " + element.getAttribute("id"));

System.out.println("Employee Name : " + element.getElementsByTagName("name").item(0).getTextContent());

System.out.println("Email: " + element.getElementsByTagName("email").item(0).getTextContent());

System.out.println("Phone: " + element.getElementsByTagName("phone").item(0).getTextContent());

}

} catch (Exception e) {

e.printStackTrace();

}

Output

Root element name :- contactbook Current element name :- employee ————————————- Employee id :- 101 Employee Name : Devil Donald Email: donald.devil@abcd.com Phone: +91 9090909090 Current element name :- employee ————————————- Employee id :- 201 Employee Name : Nevil Ray Email: ray.nevil@abcd.com Phone: +1 919191919

2. Java Program of DOM Parser with looping the nodes.

In this example we will loop through the nodes one by one and will display node name,values and attributes.


package com.codenuclear;

import java.io.File;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class ReadXMLByLoopingNode {

	 public static void main(String[] args) {

		 try {
				File xmlFile = new File("D:\\Files\\contactbook.xml");
				DocumentBuilderFactory docbuildFactory = DocumentBuilderFactory.newInstance();
				DocumentBuilder docBuilder = docbuildFactory.newDocumentBuilder();
				Document document = docBuilder.parse(xmlFile);

				System.out.println("Root element name :- " + document.getDocumentElement().getNodeName());
		    	


				if (document.hasChildNodes()) {

					printNode(document.getChildNodes());

				}

		    } catch (Exception e) {
				e.printStackTrace();
		    }

		  	}

	 public static void printNode(NodeList nodeList) {

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

			Node tempNode = nodeList.item(i);

			// Ensure that the node is Element node
			if (tempNode.getNodeType() == Node.ELEMENT_NODE) {

				// print node name and value
				System.out.println("\nNode Name =" + tempNode.getNodeName()+" STARTS");
				System.out.println("Node Value =" + tempNode.getTextContent());

				// Check if attributes present in this node
				if (tempNode.hasAttributes()) {

					// get attributes names and values
					NamedNodeMap nodeMap = tempNode.getAttributes();

					for (int j = 0; j < nodeMap.getLength(); j++) {

						Node node = nodeMap.item(j);
						System.out.println("Attribute Name : " + node.getNodeName());
						System.out.println("Attribute Value : " + node.getNodeValue());

					}

				}

				if (tempNode.hasChildNodes()) {

					// Check if child nodes present.
					printNode(tempNode.getChildNodes());

				}

				System.out.println("Node Name :- " + tempNode.getNodeName()+" ENDS");

			}

		    }
		  }
}

package com.codenuclear;

import java.io.File;

import javax.xml.parsers.DocumentBuilder;

import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;

import org.w3c.dom.NamedNodeMap;

import org.w3c.dom.Node;

import org.w3c.dom.NodeList;

public class ReadXMLByLoopingNode {

public static void main(String[] args) {

try {

File xmlFile = new File("D:\\Files\\contactbook.xml");

DocumentBuilderFactory docbuildFactory = DocumentBuilderFactory.newInstance();

DocumentBuilder docBuilder = docbuildFactory.newDocumentBuilder();

Document document = docBuilder.parse(xmlFile);

System.out.println("Root element name :- " + document.getDocumentElement().getNodeName());

if (document.hasChildNodes()) {

printNode(document.getChildNodes());

}

} catch (Exception e) {

e.printStackTrace();

}

public static void printNode(NodeList nodeList) {

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

Node tempNode = nodeList.item(i);

// Ensure that the node is Element node

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

// print node name and value

System.out.println("\nNode Name =" + tempNode.getNodeName()+" STARTS");

System.out.println("Node Value =" + tempNode.getTextContent());

// Check if attributes present in this node

if (tempNode.hasAttributes()) {

// get attributes names and values

NamedNodeMap nodeMap = tempNode.getAttributes();

for (int j = 0; j < nodeMap.getLength(); j++) {

Node node = nodeMap.item(j);

System.out.println("Attribute Name : " + node.getNodeName());

System.out.println("Attribute Value : " + node.getNodeValue());

}

if (tempNode.hasChildNodes()) {

// Check if child nodes present.

printNode(tempNode.getChildNodes());

}

System.out.println("Node Name :- " + tempNode.getNodeName()+" ENDS");

}

Output

Root element name :- contactbook Node Name =contactbook STARTS Node Value = Devil Donald donald.devil@abcd.com +91 9090909090 Nevil Ray ray.nevil@abcd.com +1 919191919 Node Name =employee STARTS Node Value = Devil Donald donald.devil@abcd.com +91 9090909090 Attribute Name : id Attribute Value : 101 Node Name =name STARTS Node Value =Devil Donald Node Name :- name ENDS Node Name =email STARTS Node Value =donald.devil@abcd.com Node Name :- email ENDS Node Name =phone STARTS Node Value =+91 9090909090 Node Name :- phone ENDS Node Name :- employee ENDS Node Name =employee STARTS Node Value = Nevil Ray ray.nevil@abcd.com +1 919191919 Attribute Name : id Attribute Value : 201 Node Name =name STARTS Node Value =Nevil Ray Node Name :- name ENDS Node Name =email STARTS Node Value =ray.nevil@abcd.com Node Name :- email ENDS Node Name =phone STARTS Node Value =+1 919191919 Node Name :- phone ENDS Node Name :- employee ENDS Node Name :- contactbook ENDS

Reference :- Reading XML