xml文档：
<?xml version="1.0" encoding="gb2312"?>
<!DOCTYPE sonnet SYSTEM "XmlDomDemo.dtd">
<sonnet type="tfnew21">
<author>
<last-name>天烽</last-name>
<first-name>三峰</first-name>
<nationality>北国</nationality>
<year-of-birth>1980</year-of-birth>
</author>
<title>天峰个人诗集散文</title>
<text>
<line>我爱的人眼睛完全不像太阳，</line>
<line>红与她的唇相比，珊瑚更红。</line>
</text>
</sonnet>
tdt文档：
<!ELEMENT sonnet(author,title?,text)>
<!ATTLIST sonnet type(tfnew21|Petrarchan)"tfnew21">
<!ELEMENT text(line,line)>
<!ELEMENT author(last-name,first-name,nationality,year-of-birth?,year-of-death?)>
<!ELEMENT title(#PCDATA)>
<!ELEMENT last-name(#PCDATA)>
<!ELEMENT first-name(#PCDATA)>
<!ELEMENT nationality(#PCDATA)>
<!ELEMENT year-of-birth(#PCDATA)>
<!ELEMENT line(#PCDATA)>
java文档：
package com.javapp.xml;
import org.apache.xerces.parsers.*;
import org.w3c.dom.*;
public class XmlDomDemo
{
public void parseAndPrint(String uri)
{
Document doc=null;
try
{
DOMParser parser=new DOMParser();
p
