在Java中读取XML格式文件

代码如下：

package com.accp.shi;   
  
import java.io.*;   
  
import org.w3c.dom.*;   
  
import javax.xml.parsers.*;   
import javax.xml.transform.*;   
import javax.xml.transform.dom.DOMSource;   
import javax.xml.transform.stream.StreamResult;   
  
public class ReadXML {   
 public static void main(String[] args){   
     
  try {   
   DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();  //文件夹制造工厂   
   DocumentBuilder bf = factory.newDocumentBuilder(); //用工厂制造出一个文件夹   
   Document doc = bf.parse("D:\\news.xml"); //使用DocumentBuilder类对象的parse()方法，来解析XML文件，并返回Document对象   
      
   NodeList channels = doc.getElementsByTagName("channel");   
   for(int i =0;i < channels.getLength(); i++){   
    Element channel = (Element)channels.item(i);   
       
    Attr idAttr = doc.createAttribute("id");   
    idAttr.setValue("hello");   
    channel.setAttributeNode(idAttr);   
    NodeList childs = channel.getChildNodes();   
    for(int j=0;j<childs.getLength();j++){   
     Node child = childs.item(j);   
     if(child.getNodeName().equals("title"))   
      System.out.println("<title>的频道标题："+child.getFirstChild().getNodeValue());   
     if(child.getNodeName().equals("description"))   
      System.out.println("<description>频道详细信息："+child.getFirstChild().getNodeValue());   
     if(child.getNodeName().equals("item")){   
      NodeList items = child.getChildNodes();   
      for(int k=0;k<items.getLength();k++){   
       Node item = items.item(k);   
       if(item.getNodeName().equals("title"))   
        System.out.println("<title>的内容是新闻标题："+item.getFirstChild().getNodeValue());   
       if(item.getNodeName().equals("link"))   
        System.out.println("<link>的内容是新闻链接："+item.getFirstChild().getNodeValue());   
       if(item.getNodeName().equals("description"))   
        System.out.println("<item>/<description>的内容是新闻简介："+item.getFirstChild().getNodeValue());   
      }   
     }   
    }   
   }   
   writeToXml(doc,"D:\\news2.xml");   
  } catch (Exception e) {   
   e.printStackTrace();   
  }     
 }   
  
 /**  
  * 将读出来的XML文件写到另一个XML文件中去  
  * 等于是新创建一个XML文件  
  * @param doc Document对象  
  * @param rptdesign 要存放的文件路径  
  */  
 private static void writeToXml(Document doc, String rptdesign) {   
  try {   
   OutputStream fileOutputStream = new FileOutputStream(rptdesign);   
   TransformerFactory tFactory = TransformerFactory.newInstance();   
   Transformer transformer = tFactory.newTransformer();   
   DOMSource source = new DOMSource(doc);   
   StreamResult result = new StreamResult(fileOutputStream);   
   transformer.transform(source, result);   
   fileOutputStream.close();   
  } catch (Exception e) {   
   e.printStackTrace();   
  }   
     
 }   
} 

 以下是要被读取的XML文件

<?xml version="1.0" encoding="UTF-8"?>  
<rss version="2.0">  
  <channel>  
    <title>新浪新闻</title>  
    <description>新浪新闻频道</description>  
    <item>  
      <title>欧文里程碑进球直追三大传奇 </title>  
      <link>http://sports.06383166011.shtml</link>  
      <description>欧锦赛预选赛</description>  
    </item>  
  </channel>  
  <channel>  
    <title>QQ新闻</title>  
    <description>QQ新闻频道</description>  
    <item>  
      <title>中国Q民已达到2.5亿</title>  
      <link>http://www.qq.com</link>  
      <description>网民新语</description>  
    </item>  
    <item>  
      <title>北京申奥成功</title>  
      <link>http://www.qq.com</link>  
      <description>网民新语</description>  
    </item>  
    <item>  
      <title>预祝北京奥运成功</title>  
      <link>http://new.163.com</link>  
      <description>网民新语</description>  
    </item>  
  </channel>  
</rss>