import java.io.*;
import org.jdom.*;
import org.jdom.output.*;
import java.util.*;
import org.jdom.input.SAXBuilder;
import org.jdom.input.DOMBuilder;
 
//	No documentation.
//	too many space lines.
//	Need to use recursion. Only print out second and third level comments.

public class h4q1
{
	public static void main(String[] argv) 
	{
		 if(argv.length !=1)
		{
			System.err.println("Usage: java h4q1 xmlfilename");
			System.exit(1);
	     }
         
		 org.jdom.Element jdomElement=null;
		 //Start parsing the xml file
		 try
			{
				SAXBuilder saxBuilder = new SAXBuilder();
				DOMBuilder domBuilder = new DOMBuilder();

				DOMOutputter domOutputter = new DOMOutputter();

				Document jdomDocument = saxBuilder.build(new File(argv[0]) );
				org.w3c.dom.Element domElement = domOutputter.output(jdomDocument.getRootElement());

				jdomElement = domBuilder.build(domElement);

			}
			catch(JDOMException e)
			{
				e.printStackTrace();
			}
			catch(NullPointerException e)
			{
				e.printStackTrace();
			}

		  if (jdomElement != null)
		 {
			 
			 outputComment(jdomElement,argv[0]);
			  
		 }
	}



		 
    
		private static void outputComment(Element document, String fileName)
		{
			 List children = document.getContent();
             Iterator iterator = children.iterator();

			 //	Vector is not needed.  Just a long string wil be fine.

		    Vector commentVector=new Vector();
			while(iterator.hasNext())
			{                 
				 Object o = iterator.next();
				  //if the node is the Comment node,put it into the vector

				  //	Handled the first level comment.
                 if (o instanceof Comment)
				 {
					  
					 commentVector.add(o);
                 }
				 //if the node is the Element node,continue get its content node,and fecth 
				 //the comment node and then add to the vector
                 else if (o instanceof Element)
				 {

						//	Handle the second level comments.
						//	Poor name choices.
						//
					  List otherChildren = ((Element)o).getContent();
                      Iterator anotherIterator = otherChildren.iterator();
					  while(anotherIterator.hasNext())
					 {
						  Object anotherObject=anotherIterator.next();
						  
						  if( anotherObject instanceof Comment)
						 {
							  
							commentVector.add(anotherObject);
							 
						 }
					 }

                 }
			}//end of while

            //output the content(comment) of the vector
			if(commentVector.size() == 0)
			{
				System.out.println("There is no comments for the XML file "+fileName);
				
			}
			else
			{
				System.out.println("Comment for the XML file "+ fileName + " => \n");
				
				for(int i=0; i<commentVector.size(); i++)
				{
					 System.out.println("COMMENT => " + ((Comment)(commentVector.elementAt(i)) ).getText());
				}
			}

		}//end of outputComment
	
}