XML Data,Java XML Data,Getting Data from XML Dile or Document

Getting Data from XML File (Document)

In this section, you will learn to retrieve the data from a XML file. All xml files store the data. You can add and modify the data in the xml document using the DOM APIs.

Description of program:

This program helps you in retrieving the data from a XML file. It takes a xml file on the console with a message "Enter xml file name: ". After getting the xml file it parses. To parse you need DocumentBuilderFactory and DocumentBuilder. Then we create a Transformer. The setOutputProperty() is an abstract method of javax.xml.transform package which invokes the Transformer object and sets an output property. In setOutputProperty() method we set the property "text" to generate the output in the text format only.

An object of Document type is passed in the DOMSource() constructor. Finally, we create a Result type object needed to generate the result. The transform() method takes the Source and Result objects and it processes the source tree to the output . Here the results are displayed at the console from the XML document.

<?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>
<Emp_Id> E-002 </Emp_Id>
<Emp_Name> Sushil </Emp_Name>
<Emp_E-mail>Sushil@yahoo.com </Emp_E-mail>
</Employee>

<Employee>
<Emp_Id> E-003 </Emp_Id>
<Emp_Name> Amit </Emp_Name>
<Emp_E-mail> Amit@yahoo.com </Emp_E-mail>
</Employee>

</Employee-Detail>

Here is the Java File: GetData.java


import java.io.*;

import org.w3c.dom.*;

import org.xml.sax.*;

import javax.xml.parsers.*;

import javax.xml.transform.*; 

import javax.xml.transform.dom.DOMSource; 

import javax.xml.transform.stream.StreamResult;



public class GetData{

  static public void main(String[] arg) {

    try{

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

      System.out.print("Enter 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);

//        Create transformer

        Transformer tFormer = TransformerFactory.newInstance().newTransformer();

//        Output text type

        tFormer.setOutputProperty(OutputKeys.METHOD, "text");

//        Write the document to a file

        Source source = new DOMSource(doc);

        Result result = new StreamResult(System.out);

        tFormer.transform(source, result);

      }

      else{

        System.out.println("File not found!");

      }

    }

    catch (Exception e){

      System.err.println(e);

      System.exit(0);

    }  

  }

}

Output of this program:

C:\vinod\xml>javac GetData.java

C:\vinod\xml>java GetData
Enter XML file name: Employee-Detail.xml

       E-001
       Vinod
       Vinod1@yahoo.com

       E-002
       Sushil
       Sushil@yahoo.com

       E-003
       Amit
       Amit@yahoo.com