Java XML DOM Example,XML Fragments,Getting Dom Tree Elements and their Corresponding XML Fragments

Getting Dom Tree Elements and their Corresponding XML Fragments

In this section, you will learn to get the elements of a DOM tree and their corresponding XML fragments. Each element of dom tree has a node level starting with '0'. Here the DOM tree elements and their corresponding XML fragments are displayed on the console.

Description of the program:

This program helps you to retrieve the elements of a DOM tree and their corresponding XML fragments on the console. To parse the xml file you need the DocumentBuilder and DoucnemtBuilderFactory. With the help of this you create a NodeList through the getElementByTagName() method. The NodeList helps you in getting the length and Element. For getting the node name you use the getNodeName() method. The transform() method displays the data source and the given destination. This program uses the "System.out" to display the data on the console.

<?xml version = "1.0" ?>
<Employee-Detail>
<Employee>
<Emp_Id> E-001 </Emp_Id>
<Emp_Name> Vinod </Emp_Name>
<Emp_E-mail> Vinod1@yahoo.com </Emp_E-mail>
</Employee>
</Employee-Detail>


import java.io.*;

import javax.xml.parsers.*;

import org.w3c.dom.*;

import org.xml.sax.*;

import javax.xml.transform.*; 

import javax.xml.transform.dom.DOMSource; 

import javax.xml.transform.stream.StreamResult;



public class DisplayElementNodes {

  static public void main(String[] arg){

    try{

      BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));

      System.out.print("Enter a XML file name: ");

      String xmlFile = bf.readLine();

      File file = new File(xmlFile);

      if (file.exists()){

        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();

        DocumentBuilder builder = factory.newDocumentBuilder();

        Document doc = builder.parse(xmlFile);

        TransformerFactory tranFactory = TransformerFactory.newInstance(); 

        Transformer aTransformer = tranFactory.newTransformer(); 

        // Get nodes list of all elements

        NodeList list = doc.getElementsByTagName("*");

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

          // Get element

          Element element = (Element)list.item(i);

          Source src = new DOMSource(element); 

          System.out.println("Node no: " + i + " is " + element.getNodeName());

          System.out.println( "Its corresponding xml representation:");

          Result dest = new StreamResult(System.out);

          aTransformer.transform(src, dest);

          System.out.println("\n");

        }

      }

      else{

        System.out.println(xmlFile + " (file name) doesn't found!");

      }

    }

    catch (Exception e){

      e.getMessage();

    }

  }

}

Output of this program:

C:\vinod\xml>javac DisplayElementNodes.java

C:\vinod\xml>java DisplayElementNodes
Enter a XML file name: Employee-Detail2.xml
Node no: 0 is Employee-Detail
Its corresponding xml representation:
<?xml version="1.0" encoding="UTF-8"?><Employee-Detail>
<Employee>
<Emp_Id> E-001 </Emp_Id>
<Emp_Name> Vinod </Emp_Name>
<Emp_E-mail> Vinod1@yahoo.com </Emp_E-mail>
</Employee>

</Employee-Detail>

Node no: 1 is Employee
Its corresponding xml representation:
<?xml version="1.0" encoding="UTF-8"?><Employee>
<Emp_Id> E-001 </Emp_Id>
<Emp_Name> Vinod </Emp_Name>
<Emp_E-mail> Vinod1@yahoo.com </Emp_E-mail>
</Employee>

Node no: 2 is Emp_Id
Its corresponding xml representation:
<?xml version="1.0" encoding="UTF-8"?><Emp_Id> E-001 </Emp_Id>

Node no: 3 is Emp_Name
Its corresponding xml representation:
<?xml version="1.0" encoding="UTF-8"?><Emp_Name> Vinod </Emp_Name>

Node no: 4 is Emp_E-mail
Its corresponding xml representation:
<?xml version="1.0" encoding="UTF-8"?><Emp_E-mail> Vinod1@yahoo.com </Emp_E-mail>