dom4j解析xml（记录）

DOM4J是dom4j.org出品的一个开源XML解析包。Dom4j是一个易用的、开源的库，用于XML，XPath和XSLT。它应用于Java平台，采用了Java集合框架并完全支持DOM，SAX和JAXP。Hibernate也是用它来读写配置文件的。  
  
一、DOM4j的下载  
dom4j-1.6.1.jar 下载：http://sourceforge.net/directory/os:windows/freshness:recently-updated/?q=dom4j  
  
二、DOM4j解析XML文件
AirPortLine.xml文件如下：

 <?xml version="1.0" encoding="UTF-8"?>
 <AirPortLine>
     <line lid="MU2480" num="3">
         <id>1</id>
         <station>
             <sid>1</sid>
             <sname>武汉</sname>
         </station>
         <station>
             <sid>2</sid>
             <sname>石家庄</sname>
         </station>
         <station>
             <sid>3</sid>
             <sname>北京</sname>
         </station>
     </line>
     <line lid="MU2483" num="4">
         <id>2</id>
         <station>
             <sid>1</sid>
             <sname>重庆</sname>
         </station>
         <station>
             <sid>2</sid>
             <sname>武汉</sname>
         </station>
         <station>
             <sid>3</sid>
             <sname>上海</sname>
         </station>
         <station>
             <sid>4</sid>
             <sname>东京</sname>
         </station>
     </line>
     <line lid="MU2485" num="2">
         <id>3</id>
         <station>
             <sid>1</sid>
             <sname>上海</sname>
         </station>
         <station>
             <sid>2</sid>
             <sname>纽约</sname>
         </station>
     </line>
 </AirPortLine>

Java DOM4J解析XML代码如下：

 package com.hsinghsu.testXML;

 import java.io.File;
 import java.util.Iterator;

 import org.dom4j.Attribute;
 import org.dom4j.Document;
 import org.dom4j.DocumentException;
 import org.dom4j.DocumentHelper;
 import org.dom4j.Element;
 import org.dom4j.io.SAXReader;

 public class testDOM4J {

     public static void main(String[] args) {

         try {
             File file = new File("AirPortLine.xml");
             SAXReader reader = new SAXReader();
             Document doc = reader.read(file);

             parseDOM4J(doc);// 解析XML文档

             //String xmlStr = getStringFromXML(doc);// 将XML文档转换为String
             //System.out.println("xmlStr:" + xmlStr);

             //String str = "<?xml version='1.0' encoding='UTF-8'?><AirPortLine><line lid='MU2480' num='3'><id>1</id><station><sid>1</sid><sname>武汉</sname></station><station><sid>2</sid><sname>石家庄</sname></station><station><sid>3</sid><sname>北京</sname></station></line><line lid='MU2482' num='4'><id>2</id><station><sid>1</sid><sname>重庆</sname></station><station><sid>2</sid><sname>武汉</sname></station><station><sid>3</sid><sname>上海</sname></station><station><sid>4</sid><sname>东京</sname></station></line><line lid='MU2483' num='2'><id>3</id><station><sid>1</sid><sname>上海</sname></station><station><sid>2</sid><sname>纽约</sname></station></line></AirPortLine>";
             //Document document = getXMLDocFromString(str);// 将String转换为XML文档

         } catch (Exception e) {
             System.out.println("Can't read the file");
         }
     }

     // 解析XML文档
     private static void parseDOM4J(Document doc) {
         Element root = doc.getRootElement();
         for (Iterator iter = root.elementIterator("line"); iter.hasNext();) {// 遍历line结点的所有子节点,也可以使用root.elementIterator()
             Element element = (Element) iter.next();

             Attribute lidAttr = element.attribute("lid");// 获取<line>元素的属性
             String lid = lidAttr.getValue();// 获取<line>元素的属性值
             Attribute numAttr = element.attribute("num");// 获取<line>元素的属性
             String num = numAttr.getValue();// 获取<line>元素的属性值

             String id = element.elementText("id");// 获取<line>元素下<id></id>的值

             System.out.println("==lid:" + lid);
             System.out.println("==num:" + num);
             System.out.println("==路线id:" + id);

             for (Iterator iterInner = element.elementIterator("station"); iterInner.hasNext();) { // 遍历station结点的所有子节点
                 Element elementInner = (Element) iterInner.next();

                 String sid = elementInner.elementText("sid");// 获取<station>元素下<sid></sid>的值
                 String sname = elementInner.elementText("sname");// 获取<station>元素下<sname></sname>的值

                 System.out.println("----站--sid:" + sid);
                 System.out.println("----站--sname:" + sname);
             }

         }
     }

     // 将XML文档转换为String
     private static String getStringFromXML(Document doc) {
         return doc.asXML();
     }

     // 将String转换为XML文档
     private static Document getXMLDocFromString(String str) {
         try {
             return DocumentHelper.parseText(str);
         } catch (DocumentException e) {
             e.printStackTrace();
             return null;
         }

 }