package org.kxml.kdom;import java.util.*;import java.io.*;import org.kxml.*;import org.kxml.io.*;import org.kxml.parser.*;/** The document consists of some legacy events and a single root    element. This class basically adds some consistency checks to    Node. */public class Document extends Node {    protected int rootIndex = -1;     /** returns "#document" */    public String getName () {	return "#document";    }    /** Adds a child at the given index position. Throws	an exception when a second root element is added */     public void addChild (int index, int type, Object child) {	if (type == Xml.ELEMENT) {	    if (rootIndex != -1) 		throw new RuntimeException 		    ("Only one document root element allowed"); 	    rootIndex = index;	}	else if (rootIndex >= index) rootIndex++;	super.addChild (index, type, child);    }    /** reads the document and checks if the last event	is END_DOCUMENT. If not, an exception is thrown.	The end event is consumed. For parsing partial        XML structures, consider using Node.parse (). */	    public void parse (AbstractXmlParser parser) throws IOException {	super.parse (parser);	if (parser.read ().getType () != Xml.END_DOCUMENT)	    throw new RuntimeException ("Document end expected!");    }     public void removeChild (int index) {	if (index == rootIndex) rootIndex = -1;	else if (index < rootIndex) rootIndex--;	super.removeChild (index);    }        /** returns the root element of this document. */    public Element getRootElement () {	if (rootIndex == -1) 	    throw new RuntimeException ("Document has no root element!");	return (Element) getChild (rootIndex);    }}