JAVA解析XML的四种方法比较

源自：http://ajava.org/course/xml/15374.html

 

 

核心提示：JAVA解析XML的四种方法比较 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( 

 

JAVA解析XML的四种方法比较

        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),

        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:

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

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 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);
 }
 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）。

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 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；

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 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。

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 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。

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 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;i<employeeList.size();i++){
               Element employee=(Element)employeeList.get(i);
               List employeeInfo=employee.getChildren();
               for(int j=0;j<employeeInfo.size();j++){
               System.out.println(((Element)employeeInfo.get(j)).getName()+“:”+((Element)employeeInfo.get(j)).getValue());

               }
            }
        } catch (JDOMException e) {

            e.printStackTrace();
        } catch (IOException e) {

            e.printStackTrace();
        }

     }
 }