import java.io.*;

// JAXP packages
import javax.xml.parsers.*;
import org.w3c.dom.*;

/**
 * DomPrint uses the Document Object Model (DOM) API to parse a given XML
 * document then print its element nodes.
 *
 * @author Thornton Rose
 * @version 1.0
 */
public class DomPrint {

   /**
    * Construct an instance of this class.
    */
   public DomPrint() {
   }

   /**
    * Print indentation for the given level (3 spaces per level).
    */
   private static void printIndentation(int level) {
      // Print indentation.
      for (int i = 0; i < level; i ++) {
         System.out.print("   ");
      }
   }

   /**
    * Print the document starting at the given node.
    */
   private static void print(Node node, int level) {
      // If not level 0, print blank line and indentation.
      if (level > 0) {
         System.out.println("");
         printIndentation(level);
      }

      // Print node name.
      System.out.println(node.getNodeName() + ":");

      // If attributes, print them.
      if (node.hasAttributes()) {
         NamedNodeMap attributes = node.getAttributes();

         if (attributes.getLength() > 0) {
            level ++;

            for (int i = 0; i < attributes.getLength(); i++) {
                Node attribute = attributes.item(i);
                printIndentation(level);
                System.out.println("." + attribute.getNodeName() + "=" +
                   attribute.getNodeValue());
            }

            level --;
         }
      }

      // Get node value.
      String value = node.getNodeValue();
      value = (value == null ? "" : value.trim());

      // If node value not empty, print it.
      if (value.length() > 0) {
         printIndentation(level);
         System.out.println(value);
      }

      // If node has children, print them.
      if (node.hasChildNodes()) {
         level ++;
         NodeList children = node.getChildNodes();

         for (int i = 0; i < children.getLength(); i ++) {
            Node child = children.item(i);
            print(child, level);
         }
      }
   }

   //--------------------------------------------------------------------------

   /**
    * Run the program.
    */
   public static void main(String[] args) {
      // If not enough args, print usage.
      if (args.length < 1) {
         System.out.println("Usage: DomPrint file");
         System.exit(0);
      }

      // Get file name from command-line.
      File docFile = new File(args[0]);

      try {
         // Get an instance of document builder factory and configure it.
         DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
         factory.setIgnoringComments(true);

         // Get a document builder from the factory.
         DocumentBuilder builder = factory.newDocumentBuilder();

         // Parse the input file.
         Document doc = builder.parse(docFile);

         // Print the document elements.
         print(doc.getDocumentElement(), 0);
      } catch(Exception ex) {
         System.out.println(ex);
      }
   }
}