Java解析XML:Jdom解析和SAX解析

今天看了Java解析XML的几种方法,记录一下

　　　　1、Jdom解析

　　　　　　(1)读取XML内容

　　

 　　private static void readXML() {
         // TODO Auto-generated method stub
         DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
         try {
             Document document = JdomTools.getDocument("src/books.xml");
             // 找节点
             NodeList tagName = document.getElementsByTagName("name");
             Node item = tagName.item(1);
             // 获取节点文本
             String textContent = item.getTextContent();
             System.out.println(textContent);
         } catch (Exception e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
     }

　　　　(2)写入新节点

　　

 　　public static void write2XML() {
         try {

             //获取要写入新节点的原dom树信息
             Document document = JdomTools.getDocument("src/books.xml");
             NodeList nodeList = document.getElementsByTagName("book");
             Node node = nodeList.item(0);
             //实例化一个新的节点对象
             Element element = document.createElement("nums");
             element.setTextContent("132");
             //追加到父节点中
             node.appendChild(element);
             //将修改后的新的dom覆盖掉原来的dom文件
             JdomTools.write2Xml(document, "src/books.xml");
         } catch (Exception e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
     }

　　(3)移除子节点

  public static void removeNode(){
         try {
             Document document = JdomTools.getDocument("src/books.xml");
     ///方法一
             //Node node = document.getElementsByTagName("nums").item(0);

             //System.out.println(node.getParentNode().getTextContent());
             //node.getParentNode().removeChild(node);
     ///方法二

             JdomTools.deleteNode(document.getElementsByTagName("book").item(0),document.getElementsByTagName("nums").item(0));
             JdomTools.write2Xml(document, "src/books.xml");
         } catch (Exception e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
     }

　　(4)替换子节点

  public static void replaceNode(){
         try {
             Document document = JdomTools.getDocument("src/books.xml");
             Element element = document.createElement("添加的");
             element.setTextContent("这是测试的内容");
             JdomTools.replaceNodeText(element, document.getElementsByTagName("price").item(0));
             JdomTools.write2Xml(document, "src/books.xml");
         } catch (Exception e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
     }

　　JdomTools工具类

 package com.xujingyang.utils;

 import javax.xml.parsers.DocumentBuilder;
 import javax.xml.parsers.DocumentBuilderFactory;
 import javax.xml.transform.Transformer;
 import javax.xml.transform.TransformerFactory;
 import javax.xml.transform.dom.DOMSource;
 import javax.xml.transform.stream.StreamResult;

 import org.w3c.dom.DOMException;
 import org.w3c.dom.Document;
 import org.w3c.dom.Node;

 public class JdomTools {

     /**
      * 查找document
      * @param path
      * @return
      * @throws Exception
      */
     public  static Document getDocument(String path) throws Exception{
         // 获取DocumentBuilder实例
         DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
         // 获取document对象
         return builder.parse(path);
     }

     /**
      * 删除节点
      * @param path
      * @param oldChild
      * @param document
      * @throws Exception
      */
     public static void deleteNode(Node document,Node oldChild ) throws Exception{
         //移除document节点下的子节点
         document.removeChild(oldChild);
     }

     /**
      * 替换子节点
      * @param document
      * @param newChild
      * @param oldChild
      */
     public static void replaceNodeText(Node newChild,Node oldChild){
         //oldChild替换替换为新的newChild节点
         oldChild.getParentNode().replaceChild(newChild, oldChild);
     }
     /**
      * 写入新节点
      * @param document
      * @param path
      * @throws Exception
      */
     public static void write2Xml(Document document,String path) throws Exception{
         //获取Transformer对象
         Transformer transformer = TransformerFactory.newInstance().newTransformer();
         //把写好的新的document树中写入新的文件(一般是覆盖原文件)
         transformer.transform(new DOMSource(document), new StreamResult(path));
     }
 }

2、SAX解析

　　　　SAX
　　　　　　Simple API for XML
　　　　开发包
　　　　　　JAXP：是SUN公司推出的解析标准实现
　　　　　　java API for xml Processing
　　　　主要包含的类和接口
　　　　　　org.w3c.dom:提供DOM方式解析XML的标准接口
　　　　　　org.xml.sax:提供SAX方式解析XML的标准接口
　　　　　　javax.xml:提供了解析XML文档的类

　　(1)普通的解析方式

 package com.xujingyang.utils;

 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 saxDom {
     public static void getDom(String XMLpath) throws Exception{
         SAXParserFactory parserFactory = SAXParserFactory.newInstance();
         SAXParser saxParser = parserFactory.newSAXParser();
         saxParser.parse(XMLpath, new DefaultHandler(){
             protected String result="";
             @Override
             public void startDocument() throws SAXException {
                 //开始解析文档
                 super.startDocument();
                 result+="document begin\r\n";
             }

             @Override
             public void startElement(String uri, String localName,
                     String qName, Attributes attributes) throws SAXException {
                 //开始解析节点
                 super.startElement(uri, localName, qName, attributes);
                 result+="\r\nelement begin";
             }
             @Override
             public void characters(char[] ch, int start, int length)
                     throws SAXException {
                 //开始读取节点内容
                 super.characters(ch, start, length);
                 result+=String.copyValueOf(ch, start, length);
             }

             @Override
             public void endDocument() throws SAXException {
                 //结束解析文档
                 super.endDocument();
                 result+="\r\ndocument end";
                 System.out.println(result);
             }

             @Override
             public void endElement(String uri, String localName, String qName)
                     throws SAXException {
                 //结束解析节点
                 super.endElement(uri, localName, qName);
                 result+="\r\nelement end";
             }
         });
     }

 }

　　(2)封装JavaBean的解析方式

　　

 package com.xujingyang.utils;

 import java.util.ArrayList;

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

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

 import com.xujingyang.domain.Book;

 public class sax4bean {
     public static ArrayList<Book> getBooks() throws Exception{
         //对象集合
         final ArrayList<Book> books=new ArrayList<Book>();
         SAXParser saxParser = SAXParserFactory.newInstance().newSAXParser();
         XMLReader reader = saxParser.getXMLReader();
         reader.setContentHandler(new DefaultHandler(){
             Book book=null;
             String nodeString;//做判断是否节点是要找的属性节点

             @Override
             public void startElement(String uri, String localName,
                     String qName, Attributes attributes) throws SAXException {
                 super.startElement(uri, localName, qName, attributes);
                 //判断节点名称是要找的对象就初始化bean
                 if("book".equals(qName)){
                     book=new Book();
                 }
                 nodeString=qName;

             }
             @Override
             public void characters(char[] ch, int start, int length)
                     throws SAXException {
                 super.characters(ch, start, length);
                 if(book!=null){
                     String textString=new String(ch, start, length);
                     if("name".equals(nodeString)){
                         book.setName(textString);
                     }else if ("aothour".equals(nodeString)) {
                         book.setAothour(textString);
                     }else if ("price".equals(nodeString)) {
                         book.setPrice(Float.parseFloat(textString));
                     }
                 }
             }

             @Override
             public void endElement(String uri, String localName, String qName)
                     throws SAXException {
                 // TODO Auto-generated method stub
                 super.endElement(uri, localName, qName);
                 //每次节点解析结束就要判断是否是一个对象结束,如果结束就将对象置空
                 if("book".equals(qName)){
                     books.add(book);
                     book=null;
                 }
                 //每次节点名称都要置空,否则就会读到空文本
                 nodeString=null;
             }
         });
         reader.parse("src/books.xml");

         return books;
     }
 }

　　对象类

 package com.xujingyang.domain;

 public class Book {
     private String name;
     private String aothour;
     private float price;
     public String getName() {
         return name;
     }
     public void setName(String name) {
         this.name = name;
     }
     public String getAothour() {
         return aothour;
     }
     public void setAothour(String aothour) {
         this.aothour = aothour;
     }
     public float getPrice() {
         return price;
     }
     public void setPrice(float price) {
         this.price = price;
     }
     @Override
     public String toString() {
         return "Book [name=" + name + ", aothour=" + aothour + ", price="
                 + price + "]";
     }

 }

要解析的XML文档

 <?xml version="1.0" encoding="UTF-8" standalone="no"?><books>
     <book>
         <name>三国演义</name>
         <aothour>罗贯中</aothour>
         <price>22</price>

     </book>
     <book>
         <name>西游记</name>
         <aothour>吴承恩</aothour>
         <price>24</price>
     </book>
 </books>