Getting the Root Element in a DOM Document : DOM Parser « XML « Java Tutorial

import java.io.File;

import javax.xml.parsers.DocumentBuilderFactory;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

public class Main {
  public static void main(String[] argv) throws Exception{
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
    factory.setValidating(true);

    factory.setExpandEntityReferences(false);

    Document doc = factory.newDocumentBuilder().parse(new File("filename"));

    Element root = null;

    NodeList list = doc.getChildNodes();
    for (int i = 0; i < list.getLength(); i++) {
      if (list.item(i) instanceof Element) {
        root = (Element) list.item(i);
        break;
      }
    }
    root = doc.getDocumentElement();
  }
}

33.2.DOM Parser
	33.2.1.	DOM Objects That Make Up the Parse Tree
	33.2.2.	A DOM Error Checker: Using DOM for Syntax Checking
	33.2.3.	A DOM Parse Tree Lister
	33.2.4.	Listing the Contents of Parse Tree Nodes: Using the DOM Parser to Extract XML Document Data
	33.2.5.	Ignorable Whitespace and Element Content
	33.2.6.	Remove the element from parent
	33.2.7.	Visiting All the Elements in a DOM Document
	33.2.8.	Getting the Root Element in a DOM Document
	33.2.9.	Getting a Node Relative to Another Node in a DOM Document
	33.2.10.	Getting the Notations in a DOM Document
	33.2.11.	Getting the Declared Entities in a DOM Document
	33.2.12.	Getting the Value of an Entity Reference in a DOM Document
	33.2.13.	Getting a DOM Element by Id
	33.2.14.	Converting an XML Fragment into a DOM Fragment
	33.2.15.	Parse an XML string: Using DOM and a StringReader.
	33.2.16.	Use DOM L3 DOMBuilder, DOMBuilderFilter DOMWriter and other DOM L3 functionality to preparse, revalidate and safe document.
	33.2.17.	Read XML as DOM
	33.2.18.	Create DOM Document out of string
	33.2.19.	Source To InputSource