XMl Parsing

There are 3 main parsers for which I have given sample code:
DOM Parser
SAX Parser
StAX Parser

Warning
DOM Parser is slow and consumes a lot of memory when it loads an XML document which contains a lot of data. Please consider SAX parser as solution for it, SAX is faster than DOM and use less memory.


Example on DOM parsing :

my.xml

<?xml version="1.0"?>
<company>
<staff id="1001">
<firstname>nag</firstname>
<lastname>R</lastname>
<nickname>King</nickname>
<salary>100000</salary>
</staff>
<staff id="2001">
<firstname>sang</firstname>
<lastname>lee</lastname>
<nickname>lee</nickname>
<salary>200000</salary>
</staff>
</company>



import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.DocumentBuilder;
import org.w3c.dom.Document;
import org.w3c.dom.NodeList;
import org.w3c.dom.Node;
import org.w3c.dom.Element;
import java.io.File;

public class ReadXMLFile {

  public static void main(String argv[]) {

    try {

File fXmlFile = new File("my.xml");
DocumentBuilderFactory dbFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder dBuilder = dbFactory.newDocumentBuilder();
Document doc = dBuilder.parse(fXmlFile);

doc.getDocumentElement().normalize();

System.out.println("Root element :" + doc.getDocumentElement().getNodeName());

NodeList nList = doc.getElementsByTagName("staff");

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

for (int temp = 0; temp < nList.getLength(); temp++) {

Node nNode = nList.item(temp);

System.out.println("\nCurrent Element :" + nNode.getNodeName());

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

Element eElement = (Element) nNode;

System.out.println("id : " + eElement.getAttribute("id"));
System.out.println("First Name : " + eElement.getElementsByTagName("firstname").item(0).getTextContent());
System.out.println("Last Name : " + eElement.getElementsByTagName("lastname").item(0).getTextContent());
System.out.println("Nick Name : " + eElement.getElementsByTagName("nickname").item(0).getTextContent());
System.out.println("Salary : " + eElement.getElementsByTagName("salary").item(0).getTextContent());

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

}