How to add new node in XML file using DOM Parser in Java?

Problem Description:

Suppose we have following XML file as an example.

<Employees>

   <Employee id="1">
       <name>abc</name>
       <age>23</age>
   </Employee >
  <Employee id="2">
       <name>xyz</name>
       <age>29</age>
   </Employee>
   <Employee id="3">
       <name>lmn</name>
       <age>34</age>
   </Employee>

</Employees>

Here requirement is to add new child node Employee. User has to enter all the relevant information related to Employee.

Steps:

1) Parse XML file or Create an instance of Document interface present in org.w3c.dom.* package.

For Creating an instance of Document interface we need to use DocumentBuilderFactory, DocumentBuilder classes present in javax.xml.parsers.* package and File class present in java.io.* package.

File file = new File(XML_file_location);

DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

DocumentBuilder builder = factory.newDocumentBuilder();

Document document = builder.parse(file);

2) Enter all relevant information related to Employee.

Figure 1

3) Now create new node (Employee) as follows.

• Create an instance of Element interface present in org.w3c.dom.* package. 

          Element child= document.createElement("Employee");

• For uniquely identifying this node we need to set its id. With the help of NodeList interface we can do this task as follows.

          NodeList list=document.getElementsByTagName("Employee");

          int count=list.getLength();

          element.setAttribute("id", String.valueOf(++count));

• Employee has some properties, for each property we need to create element as below.

           Element property = document.createElement(propertyName);

• We can set its value as below.

           property.setTextContent(value);

• One by one make these properties as a child element of Employee element as below.

           child.appendChild(property);

4) Now make this new node (Employee) as a child node of root (Employees) node.

document.getDocumentElement().appendChild(element);

5) Create an instance of Transformer class present in javax.xml.transform.* package. 

For creating an instance of Transformer class we need to use TransformerFactory class present in javax.xml.transform.* package.

TransformerFactory tFactory = TransformerFactory.newInstance();
Transformer transformer = tFactory.newTransformer();

6) Set xml file indentation (Optional)

transformer.setOutputProperty(OutputKeys.INDENT, "yes");

7) Create an instance of DOMSource class present in javax.xml.transform.dom.* package and pass instance of Document interface created in step 1.

DOMSource source = new DOMSource(document);

8) Create an instance of StreamResult class present in javax.xml.transform.stream.* package.

For creating an instance of StreamResult class first we need to create an instance of File class present in java.io.* package.

File file = new File(location_of_xml_file);
StreamResult result = new StreamResult(file);

9) Transform XML Source to a Result.

transformer.transform(source, result);

Software Required:

1. JDK
2. Eclipse
3. Maven

Note : I suggest to use latest version of all the software. If you need any help regarding these software installation please comment below I will help you.

Project Structure:

Figure 2

Java Code:

pom.xml

	<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<groupId>com.javamultiplex</groupId>
	<artifactId>DOM</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<build>
	<pluginManagement>
	<plugins>
	<plugin>
	<groupId>org.apache.maven.plugins</groupId>
	<artifactId>maven-compiler-plugin</artifactId>
	<version>3.6.1</version>
	<configuration>
	<source>1.8</source>
	<target>1.8</target>
	</configuration>
	</plugin>
	</plugins>
	</pluginManagement>
	</build>
	</project>

view raw pom.xml hosted with ❤ by GitHub

Employee.java

	package com.javamultiplex;
	public class Employee {
	private int id;
	private String name;
	private int age;
	private String gender;
	private String role;
	public String getName() {
	return name;
	}
	public void setName(String name) {
	this.name = name;
	}
	public int getAge() {
	return age;
	}
	public void setAge(int age) {
	this.age = age;
	}
	public String getGender() {
	return gender;
	}
	public void setGender(String gender) {
	this.gender = gender;
	}
	public String getRole() {
	return role;
	}
	public void setRole(String role) {
	this.role = role;
	}
	@Override
	public String toString() {
	return "Employee[id="+getId()+", name="+getName()+", gender="+getGender()+", age="+getAge()+", role="+getRole()+"]";
	}
	public int getId() {
	return id;
	}
	public void setId(int id) {
	this.id = id;
	}
	}

view raw Employee.java hosted with ❤ by GitHub

AddEmployee.java

	package com.javamultiplex;
	import java.io.BufferedReader;
	import java.io.File;
	import java.io.IOException;
	import java.io.InputStreamReader;
	import javax.xml.parsers.DocumentBuilder;
	import javax.xml.parsers.DocumentBuilderFactory;
	import javax.xml.parsers.ParserConfigurationException;
	import javax.xml.transform.OutputKeys;
	import javax.xml.transform.Transformer;
	import javax.xml.transform.TransformerException;
	import javax.xml.transform.TransformerFactory;
	import javax.xml.transform.dom.DOMSource;
	import javax.xml.transform.stream.StreamResult;
	import org.w3c.dom.Document;
	import org.w3c.dom.Element;
	import org.w3c.dom.NodeList;
	import org.xml.sax.SAXException;
	public class AddEmployee {
	public static void main(String[] args) throws IOException, ParserConfigurationException, SAXException, TransformerException {
	File file = new File("src/main/resources/employee.xml");
	BufferedReader input = null;
	try {
	input = new BufferedReader(new InputStreamReader(System.in));
	DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
	DocumentBuilder builder = factory.newDocumentBuilder();
	Document document = builder.parse(file);
	System.out.println("Enter name : ");
	String name = input.readLine();
	System.out.println("Enter gender : (male/female)");
	String gender = input.readLine();
	System.out.println("Enter age : ");
	int age = Integer.parseInt(input.readLine());
	System.out.println("Enter role : ");
	String role = input.readLine();
	Employee employee = new Employee();
	employee.setName(name);
	employee.setGender(gender);
	employee.setAge(age);
	employee.setRole(role);
	Element element = getEmployeeNode(employee, document);
	document.getDocumentElement().appendChild(element);
	TransformerFactory tFactory = TransformerFactory.newInstance();
	Transformer transformer = tFactory.newTransformer();
	transformer.setOutputProperty(OutputKeys.INDENT, "yes");
	DOMSource source = new DOMSource(document);
	StreamResult sResult = new StreamResult(file);
	transformer.transform(source, sResult);
	System.out.println("Employee has been added successfully.");
	} finally {
	if (input != null) {
	input.close();
	}
	}
	}
	private static Element getEmployeeNode(Employee employee, Document document) {
	Element element = document.createElement("Employee");
	NodeList list=document.getElementsByTagName("Employee");
	int count=list.getLength();
	element.setAttribute("id", String.valueOf(++count));
	Element name = getPropertyNode("name", document, employee.getName());
	element.appendChild(name);
	Element gender = getPropertyNode("gender", document, employee.getGender());
	element.appendChild(gender);
	Element age = getPropertyNode("age", document, String.valueOf(employee.getAge()));
	element.appendChild(age);
	Element role = getPropertyNode("role", document, employee.getRole());
	element.appendChild(role);
	return element;
	}
	private static Element getPropertyNode(String property, Document document, String value) {
	Element element = document.createElement(property);
	element.setTextContent(value);
	return element;
	}
	}

view raw AddEmployee.java hosted with ❤ by GitHub

Output:

Figure 3

employee.xml

123456789101112131415161718192021<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<Employees>
<Employee id="1">
<name>Rohit</name>
<gender>male</gender>
<age>25</age>
<role>Programmer</role>
</Employee>
<Employee id="2">
<name>Bhavna</name>
<gender>female</gender>
<age>20</age>
<role>Student</role>
</Employee>
<Employee id="3">
<name>Shubham</name>
<gender>male</gender>
<age>24</age>
<role>Singer</role>
</Employee>
</Employees>

Download Project


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References:

https://docs.oracle.com/javase/7/docs/api/javax/xml/parsers/DocumentBuilderFactory.html
https://docs.oracle.com/javase/7/docs/api/javax/xml/parsers/DocumentBuilder.html

https://docs.oracle.com/javase/7/docs/api/org/w3c/dom/Document.html

https://docs.oracle.com/javase/7/docs/api/org/w3c/dom/Element.html

https://docs.oracle.com/javase/7/docs/api/javax/xml/transform/TransformerFactory.html

https://docs.oracle.com/javase/7/docs/api/javax/xml/transform/Transformer.html

https://docs.oracle.com/javase/7/docs/api/java/io/File.html

https://docs.oracle.com/javase/7/docs/api/javax/xml/transform/dom/DOMSource.html

https://docs.oracle.com/javase/7/docs/api/javax/xml/transform/stream/StreamResult.html

Thank you friends, I hope you have clearly understood the solution of this problem. If you have any doubt, suggestion or query please feel free to comment below. You can also discuss this solution in our forum.

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