xml文档解析

XML文档解主要分为四种解析方式，官方提供的两种分别是：DOM 和 SAX,第三方分别是：JDOM 和 DOM4j

测试用的xml文档：

 <?xml version="1.0" encoding="UTF-8"?>
 <user>
     <uname type="3">zhangsan</uname>
     <uname type="2">王麻子</uname>
     <uname>lisi</uname>
     <pwd>
         123456
         <abcd>
             aaaaaaa
             <uname type="3">zhaoliu</uname>
         </abcd>
         <uname>wangwu</uname>
     </pwd>
 </user>

使用DOM解析如下：

 package com.xmldemo;

 import java.io.IOException;
 import java.io.InputStream;

 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
 import javax.xml.parsers.ParserConfigurationException;

 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.w3c.dom.NodeList;
 import org.xml.sax.SAXException;

 public class DomTest {

     public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException {
         //创建解析的工厂类
         DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory.newInstance();
         //创建解析
         DocumentBuilder documentBuilder = documentBuilderFactory.newDocumentBuilder();
         //获取user.xml的文件流 并且需要保证 xml放在src的根目录
         InputStream is = DomTest.class.getClassLoader().getResourceAsStream("user.xml");
         //创建文档对象模型
         Document document = documentBuilder.parse(is);
         //获取指定节点的集合
         NodeList nodeList = document.getElementsByTagName("uname");
         //遍历并获取
         for (int i = 0; i < nodeList.getLength(); i++) {
             Element element = (Element) nodeList.item(i);
             System.out.println(element.getTagName() + "----->" + element.getAttribute("type") + "---->" + element.getTextContent());
         }

     }
 }

 以下是SAX方式解析：

 package com.xmldemo;

 import java.io.IOException;
 import java.io.InputStream;
 import java.util.ArrayList;
 import java.util.List;

 import javax.xml.parsers.ParserConfigurationException;
 import javax.xml.parsers.SAXParser;
 import javax.xml.parsers.SAXParserFactory;

 import org.xml.sax.Attributes;
 import org.xml.sax.SAXException;
 import org.xml.sax.helpers.DefaultHandler;

 public class SaxTest {
     public static void main(String[] args) throws ParserConfigurationException, SAXException, IOException {
         //创建解析器的工厂类
         SAXParserFactory saxParserFactory = SAXParserFactory.newInstance();
         //创建解析器
         SAXParser saxParser = saxParserFactory.newSAXParser();
         //获取xml文件流
         InputStream is = SaxTest.class.getClassLoader().getResourceAsStream("user.xml");
         //创建自己的处理类
         MyHandle myHandle = new MyHandle();
         //直接进行解析
         saxParser.parse(is, myHandle);

         for (int i = 0; i < myHandle.list.size(); i++) {
             System.out.println("SaxTest.main()" + myHandle.list.get(i));
         }
     }
 }

 /**
  * 对XMl处理的方法
  * @author Bjsxt2013
  *
  */
 class MyHandle extends DefaultHandler {

     public List<String> list = new ArrayList<String>();

     private String elementName = null;

     @Override
     public void characters(char[] ch, int start, int length) throws SAXException {
         //System.out.println("MyHandle.characters()" + new String(ch, start, length));
         if (elementName != null && "uname".equals(elementName)) {
             //System.out.println(new String(ch, start, length));
             list.add(new String(ch, start, length));
         }
     }

     @Override
     public void endElement(String uri, String localName, String qName) throws SAXException {
         //System.out.println("MyHandle.endElement()" + qName);
         elementName = null;
     }

     @Override
     public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {
         //System.out.println("MyHandle.startElement()" + qName);
         elementName = qName;
     }

     @Override
     public void startDocument() throws SAXException {
         //System.out.println("MyHandle.startDocument()");
     }

     @Override
     public void endDocument() throws SAXException {
         //System.out.println("MyHandle.endDocument()");
     }
 }

以下是JDom方式解析：

 package com.xmldemo;

 import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.List;

 import org.jdom.Attribute;
 import org.jdom.Document;
 import org.jdom.Element;
 import org.jdom.JDOMException;
 import org.jdom.input.SAXBuilder;
 import org.jdom.output.Format;
 import org.jdom.output.XMLOutputter;

 /**
  * 1.如何动态生成xml文件
  * 2.如何解析xml文件
  * 3.如何修改xml文件
  *
  * 如何快速的解析xml文件
  * @author Bjsxt2013
  *
  */
 public class JdomTest {

     public static void main(String[] args) throws Exception {
         String filePath = System.getProperty("user.dir") + "\\src\\create.xml";
         //System.out.println(filePath);
         //createXml(filePath);
         parserXml(filePath);
     }

     /**
      * 解析并修改XMl文件
      * @param filePath
      * @throws JDOMException
      * @throws IOException
      */
     public static void parserXml(String filePath) throws JDOMException, IOException {
         //创建JDom的解析器
         SAXBuilder saxBuilder = new SAXBuilder();
         //获取XML对象的流
         InputStream is = JdomTest.class.getClassLoader().getResourceAsStream("create.xml");
         //解析并生成document对象
         Document document = saxBuilder.build(is);
         //获取根节点
         Element rootElement = document.getRootElement();
         //修改根节点的属性
         rootElement.setAttribute("sno", "9999");
         rootElement.setAttribute("type01", "aaaaaaaaaaaaaa");
         Attribute type = new Attribute("type", "abcdefg");
         rootElement.setAttribute(type);

         //获取指定的子节点
         Element stuName = rootElement.getChild("stuName");
         Element abcd = stuName.getChild("abcd");
         //获取节点对应的值
         //System.out.println("JdomTest.parserXml()" + abcd.getText());
         abcd.setText("唐僧");
         //The attribute already has an existing parent "student"
         //abcd.setAttribute(type);

         //获取所有的子节点
         List<Element> list = rootElement.getChildren();
         for (int i = 0; i < list.size(); i++) {
             System.out.println("JdomTest.parserXml()" + list.get(i).getName());
         }
         //创建新的节点
         Element score = new Element("score");
         score.setText("99");
         rootElement.addContent(score);
         //再所有的节点之后设置文本内容  不能直接调用setText方法
         //rootElement.setText("abcdefghijklmn");
         rootElement.addContent("abcdefghij");
         //设置写出的格式
         Format format = Format.getPrettyFormat();//格式良好的
         //Format format = Format.getCompactFormat();//格式紧凑的
         format.setEncoding("utf-8");
         //将文档对象模型写出到硬盘
         XMLOutputter xmlOutputter = new XMLOutputter(format);
         xmlOutputter.output(document, new FileOutputStream(filePath));
     }

     /**
      * 创建一个XML文件
      * @param filePath
      * @throws FileNotFoundException
      * @throws IOException
      */
     public static void createXml(String filePath) throws FileNotFoundException, IOException {
         //创建学生节点(根节点)
         Element rootElement = new Element("student");
         //添加属性
         rootElement.setAttribute("sno", "201209888");
         //创建姓名节点
         Element stuName = new Element("stuName");
         //给姓名节点设置值
         stuName.setText("柳岩");
         //创建年龄节点
         Element age = new Element("age");
         age.setText("18");
         //将节点连起来
         rootElement.addContent(stuName);
         rootElement.addContent(age);

         //创建文档对象模型
         Document document = new Document(rootElement);
         //设置写出的格式
         Format format = Format.getPrettyFormat();//格式良好的
         //Format format = Format.getCompactFormat();//格式紧凑的
         format.setEncoding("utf-8");
         //将文档对象模型写出到硬盘
         XMLOutputter xmlOutputter = new XMLOutputter(format);
         xmlOutputter.output(document, new FileOutputStream(filePath));
     }
 }