Reading xml file from java
JAXBContext jc = JAXBContext.newInstance("myPackageName");
//Create unmarshaller
Unmarshaller um = jc.createUnmarshaller();
//Unmarshal XML contents of the file myDoc.xml into your Java object instance.
MyJAXBObject myJAXBObject = (MyJAXBObject)
    um.unmarshal(new java.io.FileInputStream( "myDoc.xml" ));

DocumentBuilderFactory docFactory = DocumentBuilderFactory.newInstance();
DocumentBuilder docBuilder = docFactory.newDocumentBuilder();
Document doc = docBuilder.parse("/home/riddhish/developerworkspace/SplitString/src/com/updatexmlwithjava/two.xml");

NodeList username = doc.getElementsByTagName("username");
System.out.println("username ="+username.item(0).getTextContent());
NodeList password = doc.getElementsByTagName("password");
System.out.println("password ="+password.item(0).getTextContent());

public class TagHandler extends DefaultHandler{

//tag opening detection
public void startElement(String uri, String localName,
        String qName, Attributes attributes) throws SAXException{
    // ... your code
}
//tag closing detection
public void endElement(String uri, String localName, String qName)
        throws SAXException{
    // ... your code
}

}