Java解析XML的四种方法详解


Java解析XML的四种方法详解



XML现在已经成为一种通用的数据交换格式,平台的无关性使得很多场合都需要用到XML。本文将详细介绍用Java解析XML的四种方法



在做一般的XML数据交换过程中,我更乐意传递XML字符串,而不是格式化的XML Document。这就涉及到XML字符串和Xml Document的转换问题,说白了这是个很简单的问题,本文就各种XML解析器分别列举如下,以方便自己今后查阅。

=======================哈哈====================================
一、使用最原始的javax.xml.parsers,标准的jdk api

// 字符串转XML

String xmlStr = "......";
 StringReader sr = new StringReader(xmlStr); 
 InputSource is = new InputSource(sr); 
 DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); 
 DocumentBuilder builder=factory.newDocumentBuilder(); 
 Document doc = builder.parse(is);

//XML转字符串

TransformerFactory  tf  =  TransformerFactory.newInstance();
 Transformer t = tf.newTransformer();
 t.setOutputProperty("encoding","GB23121");//解决中文问题,试过用GBK不行
 ByteArrayOutputStream  bos  =  new  ByteArrayOutputStream();
 t.transform(new DOMSource(doc), new StreamResult(bos));
 String xmlStr = bos.toString();

这里的XML DOCUMENT为org.w3c.dom.Document

二、使用dom4j后程序变得更简单

// 字符串转XML

String xmlStr = "......";
 Document document = DocumentHelper.parseText(xmlStr);

// XML转字符串 

Document document = ...;
 String text = document.asXML();

这里的XML DOCUMENT为org.dom4j.Document

三、使用JDOM

JDOM的处理方式和第一种方法处理非常类似

//字符串转XML

String xmlStr = ".....";
 StringReader sr = new StringReader(xmlStr);
 InputSource is = new InputSource(sr);
 Document doc = (new SAXBuilder()).build(is);

//XML转字符串

Format format = Format.getPrettyFormat();
 format.setEncoding("gb2312");//设置xml文件的字符为gb2312,解决中文问题
 XMLOutputter xmlout = new XMLOutputter(format);
 ByteArrayOutputStream bo = new ByteArrayOutputStream();
 xmlout.output(doc,bo);
 String xmlStr = bo.toString();

这里的XML DOCUMENT为org.jdom.Document

四、JAVASCRIPT中的处理


//字符串转XML

var xmlStr = ".....";
 var xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
 xmlDoc.async=false;
 xmlDoc.loadXML(xmlStr);


//可以处理这个xmlDoc了

var name = xmlDoc.selectSingleNode("/person/name");
 alert(name.text);

//XML转字符串

var xmlDoc = ......;
 var xmlStr = xmlDoc.xml

这里的XML DOCUMENT为javascript版的XMLDOM

=============================我是黄金的分割线===========================


XML现在已经成为一种通用的数据交换格式,它的平台无关性,语言无关性,系统无关性,给数据集成与交互带来了极大的方便。对于XML本身的语法知识与技术细节,需要阅读相关的技术文献,这里面包括的内容有DOM(Document Object Model),DTD(Document Type Definition),SAX(Simple API for XML),XSD(Xml Schema Definition),XSLT(Extensible Stylesheet Language Transformations),具体可参阅w3c官方网站文档http://www.w3.org获取更多信息。 

XML在不同的语言里解析方式都是一样的,只不过实现的语法不同而已。基本的解析方式有两种,一种叫SAX,另一种叫DOM。SAX是基于事件流的解析,DOM是基于XML文档树结构的解析。假设我们XML的内容和结构如下: 



复制代码代码如下:




<?xml version="1.0" encoding="UTF-8"?>  
   
 <employees>  
   
 <employee>  
   
 <name>ddviplinux</name>  
   
 <sex>m</sex>  
   
 <age>30</age>  
   
 </employee>  
   
 </employees>




本文使用JAVA语言来实现DOM与SAX的XML文档生成与解析。 


首先定义一个操作XML文档的接口XmlDocument 它定义了XML文档的建立与解析的接口。 



复制代码代码如下:




package com.alisoft.facepay.framework.bean;  
   
 /**  
   
 *  
   
 * @author hongliang.dinghl  
   
 * 定义XML文档建立与解析的接口  
   
 */  
   
 public interface XmlDocument {  
   
 /**  
   
 * 建立XML文档  
   
 * @param fileName 文件全路径名称  
   
 */  
   
 public void createXml(String fileName);  
   
 /**  
   
 * 解析XML文档  
   
 * @param fileName 文件全路径名称  
   
 */  
   
 public void parserXml(String fileName);  
   
 }




1.DOM生成和解析XML文档 


为 XML 文档的已解析版本定义了一组接口。解析器读入整个文档,然后构建一个驻留内存的树结构,然后代码就可以使用 DOM 接口来操作这个树结构。优点:整个文档树在内存中,便于操作;支持删除、修改、重新排列等多种功能;缺点:将整个文档调入内存(包括无用的节点),浪费时间和空间;使用场合:一旦解析了文档还需多次访问这些数据;硬件资源充足(内存、CPU)。 


复制代码代码如下:




package com.alisoft.facepay.framework.bean;  
   
 import java.io.FileInputStream;  
   
 import java.io.FileNotFoundException;  
   
 import java.io.FileOutputStream;  
   
 import java.io.IOException;  
   
 import java.io.InputStream;  
   
 import java.io.PrintWriter;  
   
 import javax.xml.parsers.DocumentBuilder;  
   
 import javax.xml.parsers.DocumentBuilderFactory;  
   
 import javax.xml.parsers.ParserConfigurationException;  
   
 import javax.xml.transform.OutputKeys;  
   
 import javax.xml.transform.Transformer;  
   
 import javax.xml.transform.TransformerConfigurationException;  
   
 import javax.xml.transform.TransformerException;  
   
 import javax.xml.transform.TransformerFactory;  
   
 import javax.xml.transform.dom.DOMSource;  
   
 import javax.xml.transform.stream.StreamResult;  
   
 import org.w3c.dom.Document;  
   
 import org.w3c.dom.Element;  
   
 import org.w3c.dom.Node;  
   
 import org.w3c.dom.NodeList;  
   
 import org.xml.sax.SAXException;  
   
 /**  
   
 *  
   
 * @author hongliang.dinghl  
   
 * DOM生成与解析XML文档  
   
 */  
   
 public class DomDemo implements XmlDocument {  
   
 private Document document;  
   
 private String fileName;  
   
 public void init() {  
   
 try {  
   
 DocumentBuilderFactory factory = DocumentBuilderFactory  
   
 .newInstance();  
   
 DocumentBuilder builder = factory.newDocumentBuilder();  
   
 this.document = builder.newDocument();  
   
 } catch (ParserConfigurationException e) {  
   
 System.out.println(e.getMessage());  
   
 }  
   
 }  
   
 public void createXml(String fileName) {  
   
 Element root = this.document.createElement("employees");  
   
 this.document.appendChild(root);  
   
 Element employee = this.document.createElement("employee");  
   
 Element name = this.document.createElement("name");  
   
 name.appendChild(this.document.createTextNode("丁宏亮"));  
   
 employee.appendChild(name);  
   
 Element sex = this.document.createElement("sex");  
   
 sex.appendChild(this.document.createTextNode("m"));  
   
 employee.appendChild(sex);  
   
 Element age = this.document.createElement("age");  
   
 age.appendChild(this.document.createTextNode("30"));  
   
 employee.appendChild(age);  
   
 root.appendChild(employee);  
   
 TransformerFactory tf = TransformerFactory.newInstance();  
   
 try {  
   
 Transformer transformer = tf.newTransformer();  
   
 DOMSource source = new DOMSource(document);  
   
 transformer.setOutputProperty(OutputKeys.ENCODING, "gb2312");  
   
 transformer.setOutputProperty(OutputKeys.INDENT, "yes");  
   
 PrintWriter pw = new PrintWriter(new FileOutputStream(fileName));  
   
 StreamResult result = new StreamResult(pw);  
   
 transformer.transform(source, result);  
   
 System.out.println("生成XML文件成功!");  
   
 } catch (TransformerConfigurationException e) {  
   
 System.out.println(e.getMessage());  
   
 } catch (IllegalArgumentException e) {  
   
 System.out.println(e.getMessage());  
   
 } catch (FileNotFoundException e) {  
   
 System.out.println(e.getMessage());  
   
 } catch (TransformerException e) {  
   
 System.out.println(e.getMessage());  
   
 }  
   
 }  
   
 public void parserXml(String fileName) {  
   
 try {  
   
 DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();  
   
 DocumentBuilder db = dbf.newDocumentBuilder();  
   
 Document document = db.parse(fileName);  
   
 NodeList employees = document.getChildNodes();  
   
 for (int i = 0; i < employees.getLength(); i++) {  
   
 Node employee = employees.item(i);  
   
 NodeList employeeInfo = employee.getChildNodes();  
   
 for (int j = 0; j < employeeInfo.getLength(); j++) {  
   
 Node node = employeeInfo.item(j);  
   
 NodeList employeeMeta = node.getChildNodes();  
   
 for (int k = 0; k < employeeMeta.getLength(); k++) {  
   
 System.out.println(employeeMeta.item(k).getNodeName()  
   
 + ":" + employeeMeta.item(k).getTextContent());  
   
 }  
   
 }  
   
 }  
   
 System.out.println("解析完毕");  
   
 } catch (FileNotFoundException e) {  
   
 System.out.println(e.getMessage());  
   
 } catch (ParserConfigurationException e) {  
   
 System.out.println(e.getMessage());  
   
 } catch (SAXException e) {  
   
 System.out.println(e.getMessage());  
   
 } catch (IOException e) {  
   
 System.out.println(e.getMessage());  
   
 }  
   
 }  
   
 }




2.SAX生成和解析XML文档 



为解决DOM的问题,出现了SAX。SAX ,事件驱动。当解析器发现元素开始、元素结束、文本、文档的开始或结束等时,发送事件,程序员编写响应这些事件的代码,保存数据。优点:不用事先调入整个文档,占用资源少;SAX解析器代码比DOM解析器代码小,适于Applet,下载。缺点:不是持久的;事件过后,若没保存数据,那么数据就丢了;无状态性;从事件中只能得到文本,但不知该文本属于哪个元素;使用场合:Applet;只需XML文档的少量内容,很少回头访问;机器内存少; 


Java代码 



复制代码代码如下:




package com.alisoft.facepay.framework.bean;  
   
 import java.io.FileInputStream;  
   
 import java.io.FileNotFoundException;  
   
 import java.io.IOException;  
   
 import java.io.InputStream;  
   
 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;  
   
 /**  
   
 *  
   
 * @author hongliang.dinghl  
   
 * SAX文档解析  
   
 */  
   
 public class SaxDemo implements XmlDocument {  
   
 public void createXml(String fileName) {  
   
 System.out.println("<<"+filename+">>");  
   
 }  
   
 public void parserXml(String fileName) {  
   
 SAXParserFactory saxfac = SAXParserFactory.newInstance();  
   
 try {  
   
 SAXParser saxparser = saxfac.newSAXParser();  
   
 InputStream is = new FileInputStream(fileName);  
   
 saxparser.parse(is, new MySAXHandler());  
   
 } catch (ParserConfigurationException e) {  
   
 e.printStackTrace();  
   
 } catch (SAXException e) {  
   
 e.printStackTrace();  
   
 } catch (FileNotFoundException e) {  
   
 e.printStackTrace();  
   
 } catch (IOException e) {  
   
 e.printStackTrace();  
   
 }  
   
 }  
   
 }  
   
 class MySAXHandler extends DefaultHandler {  
   
 boolean hasAttribute = false;  
   
 Attributes attributes = null;  
   
 public void startDocument() throws SAXException {  
   
 System.out.println("文档开始打印了");  
   
 }  
   
 public void endDocument() throws SAXException {  
   
 System.out.println("文档打印结束了");  
   
 }  
   
 public void startElement(String uri, String localName, String qName,  
   
 Attributes attributes) throws SAXException {  
   
 if (qName.equals("employees")) {  
   
 return;  
   
 }  
   
 if (qName.equals("employee")) {  
   
 System.out.println(qName);  
   
 }  
   
 if (attributes.getLength() > 0) {  
   
 this.attributes = attributes;  
   
 this.hasAttribute = true;  
   
 }  
   
 }  
   
 public void endElement(String uri, String localName, String qName)  
   
 throws SAXException {  
   
 if (hasAttribute && (attributes != null)) {  
   
 for (int i = 0; i < attributes.getLength(); i++) {  
   
 System.out.println(attributes.getQName(0)  
   
 + attributes.getValue(0));  
   
 }  
   
 }  
   
 }  
   
 public void characters(char[] ch, int start, int length)  
   
 throws SAXException {  
   
 System.out.println(new String(ch, start, length));  
   
 }  
   
 }  
   
 package com.alisoft.facepay.framework.bean;  
   
 import java.io.FileInputStream;  
   
 import java.io.FileNotFoundException;  
   
 import java.io.IOException;  
   
 import java.io.InputStream;  
   
 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;  
   
 /**  
   
 *  
   
 * @author hongliang.dinghl  
   
 * SAX文档解析  
   
 */  
   
 public class SaxDemo implements XmlDocument {  
   
 public void createXml(String fileName) {  
   
 System.out.println("<<"+filename+">>");  
   
 }  
   
 public void parserXml(String fileName) {  
   
 SAXParserFactory saxfac = SAXParserFactory.newInstance();  
   
 try {  
   
 SAXParser saxparser = saxfac.newSAXParser();  
   
 InputStream is = new FileInputStream(fileName);  
   
 saxparser.parse(is, new MySAXHandler());  
   
 } catch (ParserConfigurationException e) {  
   
 e.printStackTrace();  
   
 } catch (SAXException e) {  
   
 e.printStackTrace();  
   
 } catch (FileNotFoundException e) {  
   
 e.printStackTrace();  
   
 } catch (IOException e) {  
   
 e.printStackTrace();  
   
 }  
   
 }  
   
 }  
   
 class MySAXHandler extends DefaultHandler {  
   
 boolean hasAttribute = false;  
   
 Attributes attributes = null;  
   
 public void startDocument() throws SAXException {  
   
 System.out.println("文档开始打印了");  
   
 }  
   
 public void endDocument() throws SAXException {  
   
 System.out.println("文档打印结束了");  
   
 }  
   
 public void startElement(String uri, String localName, String qName,  
   
 Attributes attributes) throws SAXException {  
   
 if (qName.equals("employees")) {  
   
 return;  
   
 }  
   
 if (qName.equals("employee")) {  
   
 System.out.println(qName);  
   
 }  
   
 if (attributes.getLength() > 0) {  
   
 this.attributes = attributes;  
   
 this.hasAttribute = true;  
   
 }  
   
 }  
   
 public void endElement(String uri, String localName, String qName)  
   
 throws SAXException {  
   
 if (hasAttribute && (attributes != null)) {  
   
 for (int i = 0; i < attributes.getLength(); i++) {  
   
 System.out.println(attributes.getQName(0)  
   
 + attributes.getValue(0));  
   
 }  
   
 }  
   
 }  
   
 public void characters(char[] ch, int start, int length)  
   
 throws SAXException {  
   
 System.out.println(new String(ch, start, length));  
   
 }  
   
 }




3.DOM4J生成和解析XML文档 



DOM4J 是一个非常非常优秀的Java XML API,具有性能优异、功能强大和极端易用使用的特点,同时它也是一个开放源代码的软件。如今你可以看到越来越多的 Java 软件都在使用 DOM4J 来读写 XML,特别值得一提的是连 Sun 的 JAXM 也在用 DOM4J。 



Java代码 


复制代码代码如下:




package com.alisoft.facepay.framework.bean;  
   
 import java.io.File;  
   
 import java.io.FileWriter;  
   
 import java.io.IOException;  
   
 import java.io.Writer;  
   
 import java.util.Iterator;  
   
 import org.dom4j.Document;  
   
 import org.dom4j.DocumentException;  
   
 import org.dom4j.DocumentHelper;  
   
 import org.dom4j.Element;  
   
 import org.dom4j.io.SAXReader;  
   
 import org.dom4j.io.XMLWriter;  
   
 /**  
   
 *  
   
 * @author hongliang.dinghl  
   
 * Dom4j 生成XML文档与解析XML文档  
   
 */  
   
 public class Dom4jDemo implements XmlDocument {  
   
 public void createXml(String fileName) {  
   
 Document document = DocumentHelper.createDocument();  
   
 Element employees=document.addElement("employees");  
   
 Element employee=employees.addElement("employee");  
   
 Element name= employee.addElement("name");  
   
 name.setText("ddvip");  
   
 Element sex=employee.addElement("sex");  
   
 sex.setText("m");  
   
 Element age=employee.addElement("age");  
   
 age.setText("29");  
   
 try {  
   
 Writer fileWriter=new FileWriter(fileName);  
   
 XMLWriter xmlWriter=new XMLWriter(fileWriter);  
   
 xmlWriter.write(document);  
   
 xmlWriter.close();  
   
 } catch (IOException e) {  
   
 System.out.println(e.getMessage());  
   
 }  
   
 }  
   
 public void parserXml(String fileName) {  
   
 File inputXml=new File(fileName);  
   
 SAXReader saxReader = new SAXReader();  
   
 try {  
   
 Document document = saxReader.read(inputXml);  
   
 Element employees=document.getRootElement();  
   
 for(Iterator i = employees.elementIterator(); i.hasNext();){  
   
 Element employee = (Element) i.next();  
   
 for(Iterator j = employee.elementIterator(); j.hasNext();){  
   
 Element node=(Element) j.next();  
   
 System.out.println(node.getName()+":"+node.getText());  
   
 }  
   
 }  
   
 } catch (DocumentException e) {  
   
 System.out.println(e.getMessage());  
   
 }  
   
 System.out.println("dom4j parserXml");  
   
 }  
   
 }




4.JDOM生成和解析XML 
为减少DOM、SAX的编码量,出现了JDOM;优点:20-80原则,极大减少了代码量。使用场合:要实现的功能简单,如解析、创建等,但在底层,JDOM还是使用SAX(最常用)、DOM、Xanan文档。 


复制代码代码如下:




package com.alisoft.facepay.framework.bean;  
   
 import java.io.FileNotFoundException;  
   
 import java.io.FileOutputStream;  
   
 import java.io.IOException;  
   
 import java.util.List;  
   
 import org.jdom.Document;  
   
 import org.jdom.Element;  
   
 import org.jdom.JDOMException;  
   
 import org.jdom.input.SAXBuilder;  
   
 import org.jdom.output.XMLOutputter;  
   
 /**  
   
 *  
   
 * @author hongliang.dinghl  
   
 * JDOM 生成与解析XML文档  
   
 *  
   
 */  
   
 public class JDomDemo implements XmlDocument {  
   
 public void createXml(String fileName) {  
   
 Document document;  
   
 Element root;  
   
 root=new Element("employees");  
   
 document=new Document(root);  
   
 Element employee=new Element("employee");  
   
 root.addContent(employee);  
   
 Element name=new Element("name");  
   
 name.setText("ddvip");  
   
 employee.addContent(name);  
   
 Element sex=new Element("sex");  
   
 sex.setText("m");  
   
 employee.addContent(sex);  
   
 Element age=new Element("age");  
   
 age.setText("23");  
   
 employee.addContent(age);  
   
 XMLOutputter XMLOut = new XMLOutputter();  
   
 try {  
   
 XMLOut.output(document, new FileOutputStream(fileName));  
   
 } catch (FileNotFoundException e) {  
   
 e.printStackTrace();  
   
 } catch (IOException e) {  
   
 e.printStackTrace();  
   
 }  
   
 }  
   
 public void parserXml(String fileName) {  
   
 SAXBuilder builder=new SAXBuilder(false);  
   
 try {  
   
 Document document=builder.build(fileName);  
   
 Element employees=document.getRootElement();  
   
 List employeeList=employees.getChildren("employee");  
   
 for(int i=0;iElement employee=(Element)employeeList.get(i);  
   
 List employeeInfo=employee.getChildren();  
   
 for(int j=0;jSystem.out.println(((Element)employeeInfo.get(j)).getName()+":"+((Element)employeeInfo.get(j)).getValue());  
   
 }  
   
 }  
   
 } catch (JDOMException e) {  
   
 e.printStackTrace();  
   
 } catch (IOException e) {  
   
 e.printStackTrace();  
   
 }  
   
 }  
   
 }


Java解析XML的四种方法详解



XML现在已经成为一种通用的数据交换格式,平台的无关性使得很多场合都需要用到XML。本文将详细介绍用Java解析XML的四种方法



在做一般的XML数据交换过程中,我更乐意传递XML字符串,而不是格式化的XML Document。这就涉及到XML字符串和Xml Document的转换问题,说白了这是个很简单的问题,本文就各种XML解析器分别列举如下,以方便自己今后查阅。

=======================哈哈====================================
一、使用最原始的javax.xml.parsers,标准的jdk api

// 字符串转XML

String xmlStr = "......";
 StringReader sr = new StringReader(xmlStr); 
 InputSource is = new InputSource(sr); 
 DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); 
 DocumentBuilder builder=factory.newDocumentBuilder(); 
 Document doc = builder.parse(is);

//XML转字符串

TransformerFactory  tf  =  TransformerFactory.newInstance();
 Transformer t = tf.newTransformer();
 t.setOutputProperty("encoding","GB23121");//解决中文问题,试过用GBK不行
 ByteArrayOutputStream  bos  =  new  ByteArrayOutputStream();
 t.transform(new DOMSource(doc), new StreamResult(bos));
 String xmlStr = bos.toString();

这里的XML DOCUMENT为org.w3c.dom.Document

二、使用dom4j后程序变得更简单

// 字符串转XML

String xmlStr = "......";
 Document document = DocumentHelper.parseText(xmlStr);

// XML转字符串 

Document document = ...;
 String text = document.asXML();

这里的XML DOCUMENT为org.dom4j.Document

三、使用JDOM

JDOM的处理方式和第一种方法处理非常类似

//字符串转XML

String xmlStr = ".....";
 StringReader sr = new StringReader(xmlStr);
 InputSource is = new InputSource(sr);
 Document doc = (new SAXBuilder()).build(is);

//XML转字符串

Format format = Format.getPrettyFormat();
 format.setEncoding("gb2312");//设置xml文件的字符为gb2312,解决中文问题
 XMLOutputter xmlout = new XMLOutputter(format);
 ByteArrayOutputStream bo = new ByteArrayOutputStream();
 xmlout.output(doc,bo);
 String xmlStr = bo.toString();

这里的XML DOCUMENT为org.jdom.Document

四、JAVASCRIPT中的处理


//字符串转XML

var xmlStr = ".....";
 var xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
 xmlDoc.async=false;
 xmlDoc.loadXML(xmlStr);
 //可以处理这个xmlDoc了
 var name = xmlDoc.selectSingleNode("/person/name");
 alert(name.text);

//XML转字符串

var xmlDoc = ......;
 var xmlStr = xmlDoc.xml

这里的XML DOCUMENT为javascript版的XMLDOM

=============================我是黄金的分割线===========================


XML现在已经成为一种通用的数据交换格式,它的平台无关性,语言无关性,系统无关性,给数据集成与交互带来了极大的方便。对于XML本身的语法知识与技术细节,需要阅读相关的技术文献,这里面包括的内容有DOM(Document Object Model),DTD(Document Type Definition),SAX(Simple API for XML),XSD(Xml Schema Definition),XSLT(Extensible Stylesheet Language Transformations),具体可参阅w3c官方网站文档http://www.w3.org获取更多信息。 

XML在不同的语言里解析方式都是一样的,只不过实现的语法不同而已。基本的解析方式有两种,一种叫SAX,另一种叫DOM。SAX是基于事件流的解析,DOM是基于XML文档树结构的解析。假设我们XML的内容和结构如下: 



复制代码代码如下:




<?xml version="1.0" encoding="UTF-8"?>  
   
 <employees>  
   
 <employee>  
   
 <name>ddviplinux</name>  
   
 <sex>m</sex>  
   
 <age>30</age>  
   
 </employee>  
   
 </employees>




本文使用JAVA语言来实现DOM与SAX的XML文档生成与解析。 


首先定义一个操作XML文档的接口XmlDocument 它定义了XML文档的建立与解析的接口。 



复制代码代码如下:




package com.alisoft.facepay.framework.bean;  
   
 /**  
   
 *  
   
 * @author hongliang.dinghl  
   
 * 定义XML文档建立与解析的接口  
   
 */  
   
 public interface XmlDocument {  
   
 /**  
   
 * 建立XML文档  
   
 * @param fileName 文件全路径名称  
   
 */  
   
 public void createXml(String fileName);  
   
 /**  
   
 * 解析XML文档  
   
 * @param fileName 文件全路径名称  
   
 */  
   
 public void parserXml(String fileName);  
   
 }




1.DOM生成和解析XML文档 


为 XML 文档的已解析版本定义了一组接口。解析器读入整个文档,然后构建一个驻留内存的树结构,然后代码就可以使用 DOM 接口来操作这个树结构。优点:整个文档树在内存中,便于操作;支持删除、修改、重新排列等多种功能;缺点:将整个文档调入内存(包括无用的节点),浪费时间和空间;使用场合:一旦解析了文档还需多次访问这些数据;硬件资源充足(内存、CPU)。 


复制代码代码如下:




package com.alisoft.facepay.framework.bean;  
   
 import java.io.FileInputStream;  
   
 import java.io.FileNotFoundException;  
   
 import java.io.FileOutputStream;  
   
 import java.io.IOException;  
   
 import java.io.InputStream;  
   
 import java.io.PrintWriter;  
   
 import javax.xml.parsers.DocumentBuilder;  
   
 import javax.xml.parsers.DocumentBuilderFactory;  
   
 import javax.xml.parsers.ParserConfigurationException;  
   
 import javax.xml.transform.OutputKeys;  
   
 import javax.xml.transform.Transformer;  
   
 import javax.xml.transform.TransformerConfigurationException;  
   
 import javax.xml.transform.TransformerException;  
   
 import javax.xml.transform.TransformerFactory;  
   
 import javax.xml.transform.dom.DOMSource;  
   
 import javax.xml.transform.stream.StreamResult;  
   
 import org.w3c.dom.Document;  
   
 import org.w3c.dom.Element;  
   
 import org.w3c.dom.Node;  
   
 import org.w3c.dom.NodeList;  
   
 import org.xml.sax.SAXException;  
   
 /**  
   
 *  
   
 * @author hongliang.dinghl  
   
 * DOM生成与解析XML文档  
   
 */  
   
 public class DomDemo implements XmlDocument {  
   
 private Document document;  
   
 private String fileName;  
   
 public void init() {  
   
 try {  
   
 DocumentBuilderFactory factory = DocumentBuilderFactory  
   
 .newInstance();  
   
 DocumentBuilder builder = factory.newDocumentBuilder();  
   
 this.document = builder.newDocument();  
   
 } catch (ParserConfigurationException e) {  
   
 System.out.println(e.getMessage());  
   
 }  
   
 }  
   
 public void createXml(String fileName) {  
   
 Element root = this.document.createElement("employees");  
   
 this.document.appendChild(root);  
   
 Element employee = this.document.createElement("employee");  
   
 Element name = this.document.createElement("name");  
   
 name.appendChild(this.document.createTextNode("丁宏亮"));  
   
 employee.appendChild(name);  
   
 Element sex = this.document.createElement("sex");  
   
 sex.appendChild(this.document.createTextNode("m"));  
   
 employee.appendChild(sex);  
   
 Element age = this.document.createElement("age");  
   
 age.appendChild(this.document.createTextNode("30"));  
   
 employee.appendChild(age);  
   
 root.appendChild(employee);  
   
 TransformerFactory tf = TransformerFactory.newInstance();  
   
 try {  
   
 Transformer transformer = tf.newTransformer();  
   
 DOMSource source = new DOMSource(document);  
   
 transformer.setOutputProperty(OutputKeys.ENCODING, "gb2312");  
   
 transformer.setOutputProperty(OutputKeys.INDENT, "yes");  
   
 PrintWriter pw = new PrintWriter(new FileOutputStream(fileName));  
   
 StreamResult result = new StreamResult(pw);  
   
 transformer.transform(source, result);  
   
 System.out.println("生成XML文件成功!");  
   
 } catch (TransformerConfigurationException e) {  
   
 System.out.println(e.getMessage());  
   
 } catch (IllegalArgumentException e) {  
   
 System.out.println(e.getMessage());  
   
 } catch (FileNotFoundException e) {  
   
 System.out.println(e.getMessage());  
   
 } catch (TransformerException e) {  
   
 System.out.println(e.getMessage());  
   
 }  
   
 }  
   
 public void parserXml(String fileName) {  
   
 try {  
   
 DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();  
   
 DocumentBuilder db = dbf.newDocumentBuilder();  
   
 Document document = db.parse(fileName);  
   
 NodeList employees = document.getChildNodes();  
   
 for (int i = 0; i < employees.getLength(); i++) {  
   
 Node employee = employees.item(i);  
   
 NodeList employeeInfo = employee.getChildNodes();  
   
 for (int j = 0; j < employeeInfo.getLength(); j++) {  
   
 Node node = employeeInfo.item(j);  
   
 NodeList employeeMeta = node.getChildNodes();  
   
 for (int k = 0; k < employeeMeta.getLength(); k++) {  
   
 System.out.println(employeeMeta.item(k).getNodeName()  
   
 + ":" + employeeMeta.item(k).getTextContent());  
   
 }  
   
 }  
   
 }  
   
 System.out.println("解析完毕");  
   
 } catch (FileNotFoundException e) {  
   
 System.out.println(e.getMessage());  
   
 } catch (ParserConfigurationException e) {  
   
 System.out.println(e.getMessage());  
   
 } catch (SAXException e) {  
   
 System.out.println(e.getMessage());  
   
 } catch (IOException e) {  
   
 System.out.println(e.getMessage());  
   
 }  
   
 }  
   
 }




2.SAX生成和解析XML文档 



为解决DOM的问题,出现了SAX。SAX ,事件驱动。当解析器发现元素开始、元素结束、文本、文档的开始或结束等时,发送事件,程序员编写响应这些事件的代码,保存数据。优点:不用事先调入整个文档,占用资源少;SAX解析器代码比DOM解析器代码小,适于Applet,下载。缺点:不是持久的;事件过后,若没保存数据,那么数据就丢了;无状态性;从事件中只能得到文本,但不知该文本属于哪个元素;使用场合:Applet;只需XML文档的少量内容,很少回头访问;机器内存少; 


Java代码 



复制代码代码如下:




package com.alisoft.facepay.framework.bean;  
   
 import java.io.FileInputStream;  
   
 import java.io.FileNotFoundException;  
   
 import java.io.IOException;  
   
 import java.io.InputStream;  
   
 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;  
   
 /**  
   
 *  
   
 * @author hongliang.dinghl  
   
 * SAX文档解析  
   
 */  
   
 public class SaxDemo implements XmlDocument {  
   
 public void createXml(String fileName) {  
   
 System.out.println("<<"+filename+">>");  
   
 }  
   
 public void parserXml(String fileName) {  
   
 SAXParserFactory saxfac = SAXParserFactory.newInstance();  
   
 try {  
   
 SAXParser saxparser = saxfac.newSAXParser();  
   
 InputStream is = new FileInputStream(fileName);  
   
 saxparser.parse(is, new MySAXHandler());  
   
 } catch (ParserConfigurationException e) {  
   
 e.printStackTrace();  
   
 } catch (SAXException e) {  
   
 e.printStackTrace();  
   
 } catch (FileNotFoundException e) {  
   
 e.printStackTrace();  
   
 } catch (IOException e) {  
   
 e.printStackTrace();  
   
 }  
   
 }  
   
 }  
   
 class MySAXHandler extends DefaultHandler {  
   
 boolean hasAttribute = false;  
   
 Attributes attributes = null;  
   
 public void startDocument() throws SAXException {  
   
 System.out.println("文档开始打印了");  
   
 }  
   
 public void endDocument() throws SAXException {  
   
 System.out.println("文档打印结束了");  
   
 }  
   
 public void startElement(String uri, String localName, String qName,  
   
 Attributes attributes) throws SAXException {  
   
 if (qName.equals("employees")) {  
   
 return;  
   
 }  
   
 if (qName.equals("employee")) {  
   
 System.out.println(qName);  
   
 }  
   
 if (attributes.getLength() > 0) {  
   
 this.attributes = attributes;  
   
 this.hasAttribute = true;  
   
 }  
   
 }  
   
 public void endElement(String uri, String localName, String qName)  
   
 throws SAXException {  
   
 if (hasAttribute && (attributes != null)) {  
   
 for (int i = 0; i < attributes.getLength(); i++) {  
   
 System.out.println(attributes.getQName(0)  
   
 + attributes.getValue(0));  
   
 }  
   
 }  
   
 }  
   
 public void characters(char[] ch, int start, int length)  
   
 throws SAXException {  
   
 System.out.println(new String(ch, start, length));  
   
 }  
   
 }  
   
 package com.alisoft.facepay.framework.bean;  
   
 import java.io.FileInputStream;  
   
 import java.io.FileNotFoundException;  
   
 import java.io.IOException;  
   
 import java.io.InputStream;  
   
 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;  
   
 /**  
   
 *  
   
 * @author hongliang.dinghl  
   
 * SAX文档解析  
   
 */  
   
 public class SaxDemo implements XmlDocument {  
   
 public void createXml(String fileName) {  
   
 System.out.println("<<"+filename+">>");  
   
 }  
   
 public void parserXml(String fileName) {  
   
 SAXParserFactory saxfac = SAXParserFactory.newInstance();  
   
 try {  
   
 SAXParser saxparser = saxfac.newSAXParser();  
   
 InputStream is = new FileInputStream(fileName);  
   
 saxparser.parse(is, new MySAXHandler());  
   
 } catch (ParserConfigurationException e) {  
   
 e.printStackTrace();  
   
 } catch (SAXException e) {  
   
 e.printStackTrace();  
   
 } catch (FileNotFoundException e) {  
   
 e.printStackTrace();  
   
 } catch (IOException e) {  
   
 e.printStackTrace();  
   
 }  
   
 }  
   
 }  
   
 class MySAXHandler extends DefaultHandler {  
   
 boolean hasAttribute = false;  
   
 Attributes attributes = null;  
   
 public void startDocument() throws SAXException {  
   
 System.out.println("文档开始打印了");  
   
 }  
   
 public void endDocument() throws SAXException {  
   
 System.out.println("文档打印结束了");  
   
 }  
   
 public void startElement(String uri, String localName, String qName,  
   
 Attributes attributes) throws SAXException {  
   
 if (qName.equals("employees")) {  
   
 return;  
   
 }  
   
 if (qName.equals("employee")) {  
   
 System.out.println(qName);  
   
 }  
   
 if (attributes.getLength() > 0) {  
   
 this.attributes = attributes;  
   
 this.hasAttribute = true;  
   
 }  
   
 }  
   
 public void endElement(String uri, String localName, String qName)  
   
 throws SAXException {  
   
 if (hasAttribute && (attributes != null)) {  
   
 for (int i = 0; i < attributes.getLength(); i++) {  
   
 System.out.println(attributes.getQName(0)  
   
 + attributes.getValue(0));  
   
 }  
   
 }  
   
 }  
   
 public void characters(char[] ch, int start, int length)  
   
 throws SAXException {  
   
 System.out.println(new String(ch, start, length));  
   
 }  
   
 }




3.DOM4J生成和解析XML文档 



DOM4J 是一个非常非常优秀的Java XML API,具有性能优异、功能强大和极端易用使用的特点,同时它也是一个开放源代码的软件。如今你可以看到越来越多的 Java 软件都在使用 DOM4J 来读写 XML,特别值得一提的是连 Sun 的 JAXM 也在用 DOM4J。 



Java代码 


复制代码代码如下:




package com.alisoft.facepay.framework.bean;  
   
 import java.io.File;  
   
 import java.io.FileWriter;  
   
 import java.io.IOException;  
   
 import java.io.Writer;  
   
 import java.util.Iterator;  
   
 import org.dom4j.Document;  
   
 import org.dom4j.DocumentException;  
   
 import org.dom4j.DocumentHelper;  
   
 import org.dom4j.Element;  
   
 import org.dom4j.io.SAXReader;  
   
 import org.dom4j.io.XMLWriter;  
   
 /**  
   
 *  
   
 * @author hongliang.dinghl  
   
 * Dom4j 生成XML文档与解析XML文档  
   
 */  
   
 public class Dom4jDemo implements XmlDocument {  
   
 public void createXml(String fileName) {  
   
 Document document = DocumentHelper.createDocument();  
   
 Element employees=document.addElement("employees");  
   
 Element employee=employees.addElement("employee");  
   
 Element name= employee.addElement("name");  
   
 name.setText("ddvip");  
   
 Element sex=employee.addElement("sex");  
   
 sex.setText("m");  
   
 Element age=employee.addElement("age");  
   
 age.setText("29");  
   
 try {  
   
 Writer fileWriter=new FileWriter(fileName);  
   
 XMLWriter xmlWriter=new XMLWriter(fileWriter);  
   
 xmlWriter.write(document);  
   
 xmlWriter.close();  
   
 } catch (IOException e) {  
   
 System.out.println(e.getMessage());  
   
 }  
   
 }  
   
 public void parserXml(String fileName) {  
   
 File inputXml=new File(fileName);  
   
 SAXReader saxReader = new SAXReader();  
   
 try {  
   
 Document document = saxReader.read(inputXml);  
   
 Element employees=document.getRootElement();  
   
 for(Iterator i = employees.elementIterator(); i.hasNext();){  
   
 Element employee = (Element) i.next();  
   
 for(Iterator j = employee.elementIterator(); j.hasNext();){  
   
 Element node=(Element) j.next();  
   
 System.out.println(node.getName()+":"+node.getText());  
   
 }  
   
 }  
   
 } catch (DocumentException e) {  
   
 System.out.println(e.getMessage());  
   
 }  
   
 System.out.println("dom4j parserXml");  
   
 }  
   
 }




4.JDOM生成和解析XML 
为减少DOM、SAX的编码量,出现了JDOM;优点:20-80原则,极大减少了代码量。使用场合:要实现的功能简单,如解析、创建等,但在底层,JDOM还是使用SAX(最常用)、DOM、Xanan文档。 


复制代码代码如下:




package com.alisoft.facepay.framework.bean;  
   
 import java.io.FileNotFoundException;  
   
 import java.io.FileOutputStream;  
   
 import java.io.IOException;  
   
 import java.util.List;  
   
 import org.jdom.Document;  
   
 import org.jdom.Element;  
   
 import org.jdom.JDOMException;  
   
 import org.jdom.input.SAXBuilder;  
   
 import org.jdom.output.XMLOutputter;  
   
 /**  
   
 *  
   
 * @author hongliang.dinghl  
   
 * JDOM 生成与解析XML文档  
   
 *  
   
 */  
   
 public class JDomDemo implements XmlDocument {  
   
 public void createXml(String fileName) {  
   
 Document document;  
   
 Element root;  
   
 root=new Element("employees");  
   
 document=new Document(root);  
   
 Element employee=new Element("employee");  
   
 root.addContent(employee);  
   
 Element name=new Element("name");  
   
 name.setText("ddvip");  
   
 employee.addContent(name);  
   
 Element sex=new Element("sex");  
   
 sex.setText("m");  
   
 employee.addContent(sex);  
   
 Element age=new Element("age");  
   
 age.setText("23");  
   
 employee.addContent(age);  
   
 XMLOutputter XMLOut = new XMLOutputter();  
   
 try {  
   
 XMLOut.output(document, new FileOutputStream(fileName));  
   
 } catch (FileNotFoundException e) {  
   
 e.printStackTrace();  
   
 } catch (IOException e) {  
   
 e.printStackTrace();  
   
 }  
   
 }  
   
 public void parserXml(String fileName) {  
   
 SAXBuilder builder=new SAXBuilder(false);  
   
 try {  
   
 Document document=builder.build(fileName);  
   
 Element employees=document.getRootElement();  
   
 List employeeList=employees.getChildren("employee");  
   
 for(int i=0;iElement employee=(Element)employeeList.get(i);  
   
 List employeeInfo=employee.getChildren();  
   
 for(int j=0;jSystem.out.println(((Element)employeeInfo.get(j)).getName()+":"+((Element)employeeInfo.get(j)).getValue());  
   
 }  
   
 }  
   
 } catch (JDOMException e) {  
   
 e.printStackTrace();  
   
 } catch (IOException e) {  
   
 e.printStackTrace();  
   
 }  
   
 }  
   
 }