DOM,SAX,JDOM,DOM4J优缺点比较及生产xml和解析xml

下载必要的jar包：

activation.jar commons-logging-1.0.4.jar dom4j-1.6.1.jar jaxen-1.1.1.jar jdom-1.0.jar

一、DOM

解析器读入整个文档，然后构建一个驻留内存的树结构，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；访问效率高。 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）

[java] view plain copy package xmlParse;    import java.io.File;  import java.io.FileNotFoundException;  import java.io.FileOutputStream;  import java.io.IOException;  import java.util.Calendar;  import java.util.Locale;  import java.util.TimeZone;    import javax.xml.parsers.DocumentBuilder;  import javax.xml.parsers.DocumentBuilderFactory;  import javax.xml.parsers.ParserConfigurationException;  import javax.xml.parsers.SAXParser;  import javax.xml.parsers.SAXParserFactory;  import javax.xml.transform.Result;  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.DOMException;  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;    /**  * java自带的dom解析xml文件  *   * @author abc  *   */  public class TestDom {      public static void main(String[] args) {          builXmlByDom();          parseXmlByDom();      }      /**      * 生成xml信息      */      public static void builXmlByDom() {          long begintime = System.currentTimeMillis();          DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();          try {              //构建Document              DocumentBuilder db = dbf.newDocumentBuilder();              Document doc=db.newDocument();              Element root=doc.createElement("students");              root.setAttribute("class", "一班");              root.setAttribute("count", "3");                            Element stu=doc.createElement("student");              Element name=doc.createElement("name");              name.appendChild(doc.createTextNode("小明"));              Element age=doc.createElement("age");              age.appendChild(doc.createTextNode("10"));              stu.appendChild(name);              stu.appendChild(age);              root.appendChild(stu);                                           stu=doc.createElement("student");               stu.setAttribute("position","班长");               name=doc.createElement("name");               name.appendChild(doc.createTextNode("小王"));               age=doc.createElement("age");               age.appendChild(doc.createTextNode("11"));               stu.appendChild(name);               stu.appendChild(age);               root.appendChild(stu);                 stu=doc.createElement("student");               name=doc.createElement("name");               name.appendChild(doc.createTextNode("小兵"));               age=doc.createElement("age");               age.appendChild(doc.createTextNode("12"));               stu.appendChild(name);               stu.appendChild(age);               root.appendChild(stu);                              doc.appendChild(root);               //将被变换的Document对象封装到一个DOMSource对象中               DOMSource xmlSource=new DOMSource(doc);               //使用 Transformer对象将一个Document节点变换为一个XML文件               TransformerFactory transFactory=TransformerFactory. newInstance();               Transformer transformer=transFactory.newTransformer();                              //创建Result               File file=new File("students.xml");               FileOutputStream fos;               fos = new FileOutputStream(file);               StreamResult result=new StreamResult(fos);               transformer.transform(xmlSource, result);               if(fos!=null){                   fos.close();               }          }catch (ParserConfigurationException e) {              e.printStackTrace();          }catch (TransformerConfigurationException e) {              e.printStackTrace();          }catch (FileNotFoundException e) {              e.printStackTrace();          }catch (TransformerException e) {              e.printStackTrace();          }catch (IOException e) {              e.printStackTrace();          }            System.out.println("dom生成时间(毫秒)"                  + (System.currentTimeMillis() - begintime));      }      /**      * 解析xml信息      */      public static void parseXmlByDom() {          long begintime = System.currentTimeMillis();;          try {              DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();              DocumentBuilder builder=dbf.newDocumentBuilder();              File file=new File("students.xml");              Document doc=builder.parse(file);              NodeList students=doc.getFirstChild().getChildNodes();              Node student=null;              Node node=null;              for(int i=0,len=students.getLength();i<len;i++){                  student=students.item(i);                  NodeList childs=student.getChildNodes();                  System.out.println("第"+(i+1)+"个学生");                  for(int j=0,size=childs.getLength();j<size;j++){                      node=childs.item(j);                      if("name".equals(node.getNodeName())){                          System.out.println(node.getNodeName()+"---"+node.getTextContent());                      }                      if("age".equals(node.getNodeName())){                          System.out.println(node.getNodeName()+"---"+node.getTextContent());                      }                  }              }          } catch (DOMException e) {              e.printStackTrace();          } catch (ParserConfigurationException e) {              e.printStackTrace();          } catch (SAXException e) {              e.printStackTrace();          } catch (IOException e) {              e.printStackTrace();          }          System.out.println("dom解析时间(毫秒)"                  + (System.currentTimeMillis() - begintime));      }  }   二、SAX

特点：  1、边读边解析，应用于大型XML文档

              2、只支持读

              3、访问效率低

              4、顺序访问

[java] view plain copy package xmlParse;    import java.io.File;    import javax.xml.parsers.SAXParser;  import javax.xml.parsers.SAXParserFactory;    public class TestSAXParse {        /**      * @param args      */      public static void main(String[] args) {          sax();      }        public static void sax() {          long begintime = System.currentTimeMillis();          File f = new File("students.xml");          SAXParserFactory sf = SAXParserFactory.newInstance();          try {              SAXParser sp = sf.newSAXParser();              SAXHandler handler = new SAXHandler();              sp.parse(f, handler);          } catch (Exception e) {              e.printStackTrace();          }          System.out.println("sax解析时间(毫秒)"                  + (System.currentTimeMillis() - begintime));        }  }        SAXHandler.java  package xmlParse;    import org.xml.sax.Attributes;  import org.xml.sax.SAXException;  import org.xml.sax.helpers.DefaultHandler;  import java.util.Stack;  public class SAXHandler extends DefaultHandler {      Stack tags = null;      @Override      public void startDocument() throws SAXException {          tags=new Stack();      }        @Override      public void endDocument() throws SAXException {          while(!tags.isEmpty()){              System.out.println(tags.peek());              tags.pop();          }          tags=null;      }        @Override      public void startElement(String uri, String localName, String qName,              Attributes attributes) throws SAXException {          if("students".equals(qName)){              System.out.println(attributes.getValue("class")+"--人数-"+attributes.getValue("count"));          }          tags.push(qName);//压入栈      }        @Override      public void endElement(String uri, String localName, String qName)              throws SAXException {          tags.pop();//取出栈顶元素      }        @Override      public void characters(char[] ch, int start, int length)              throws SAXException {          String tag=(String) tags.peek();//查看栈顶元素，但不移除          if("name".equals(tag)){              System.out.println("name==="+new String(ch,start,length));          }          if("age".equals(tag)){              System.out.println("age==="+new String(ch,start,length));          }      }    }  

三、JDOM

JDOM 优点:①是基于树的处理XML的Java API，把树加载在内存中      ②没有向下兼容的限制，因此比DOM简单      ③速度快，缺陷少      ④具有SAX的Java规则 缺点:①不能处理大于内存的文档      ②JDOM表示XML文档逻辑模型。不能保证每个字节真正变换。      ③针对实例文档不提供DTD与模式的任何实际模型。      ④不支持与DOM中相应遍历包 最适合于:JDOM具有树的便利，也有SAX的JAVA规则。在需要平衡时使用

[java] view plain copy JDOM      package xmlParse;    import java.io.ByteArrayOutputStream;  import java.io.File;  import java.io.FileInputStream;  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;    public class TestJDOM {        /**      * @param args      */      public static void main(String[] args) {          buildXmlByJDOM();          parseXmlByJDOM();      }            public static String buildXmlByJDOM(){          Document doc=new Document();          Element root=new Element("students");          root.setAttribute("count", "3");          root.setAttribute("class", "一班");          doc.setRootElement(root);          root.addContent(new Element("student").addContent(new Element("name").setText("小明"))                  .addContent(new Element("age").setText("10")));          root.addContent(new Element("student").addContent(new Element("name").setText("小汪"))                  .addContent(new Element("age").setText("11")));          root.addContent(new Element("student").addContent(new Element("name").setText("小兵"))                  .addContent(new Element("age").setText("12")));          ByteArrayOutputStream out=new ByteArrayOutputStream();          XMLOutputter putter=new XMLOutputter();          try {              putter.output(doc, out);              putter.output(doc, new FileOutputStream("students.xml"));          } catch (FileNotFoundException e) {              e.printStackTrace();          } catch (IOException e) {              e.printStackTrace();          }          return out.toString();      }     public static void parseXmlByJDOM(){         long begintime=System.currentTimeMillis();         File f=new File("students.xml");           SAXBuilder builder=new SAXBuilder();         try {          Document doc=builder.build(new FileInputStream(f));          Element root=doc.getRootElement();          System.out.println(root.getAttributeValue("class")+"-人数：--"+root.getAttributeValue("count"));                    List list=root.getChildren("student");          for(int i=0;i<list.size();i++){              Element ele=(Element)list.get(i);              System.out.println("第"+(i+1)+"个学生");              System.out.println(ele.getChildText("name")+"---"+ele.getChildText("age"));          }          } catch (FileNotFoundException e) {              e.printStackTrace();          } catch (JDOMException e) {              e.printStackTrace();          } catch (IOException e) {              e.printStackTrace();          }          System.out.println("sax解析时间(毫秒)"+(System.currentTimeMillis()-begintime));     }  }   四、DOM4J

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] view plain copy DOM4J  package xmlParse;    import java.io.File;  import java.io.FileInputStream;  import java.io.FileNotFoundException;  import java.io.FileWriter;  import java.io.IOException;  import java.io.UnsupportedEncodingException;  import java.util.Iterator;  import java.util.List;    import org.dom4j.Document;  import org.dom4j.DocumentException;  import org.dom4j.DocumentHelper;  import org.dom4j.Element;  import org.dom4j.Node;  import org.dom4j.io.OutputFormat;  import org.dom4j.io.SAXReader;  import org.dom4j.io.XMLWriter;    public class TestDom4J {        /**      * @param args      */      public static void main(String[] args) {          buildXmlByDOM4J();          paserXmlByDOM4J();      }      public static void buildXmlByDOM4J(){          Document doc=DocumentHelper.createDocument();          doc.setXMLEncoding("UTF-8");          Element root=doc.addElement("students");          root.addAttribute("class", "一班").addAttribute("count", "3");          Element student=root.addElement("student");          student.addElement("name").setText("小明");          student.addElement("age").setText("10");                    student=root.addElement("student").addAttribute("position", "班长");          student.addElement("name").setText("小汪");          student.addElement("age").setText("11");                student=root.addElement("student");          student.addElement("name").setText("小兵");          student.addElement("age").setText("12");                    String xmlStr=doc.asXML();          try {              OutputFormat format=OutputFormat.createPrettyPrint();              XMLWriter writer=new XMLWriter(new FileWriter(new File("students.xml")),format);              writer.setEscapeText(false);              writer.write(xmlStr);              writer.close();          } catch (UnsupportedEncodingException e) {              e.printStackTrace();          } catch (FileNotFoundException e) {              e.printStackTrace();          }catch (IOException e) {              e.printStackTrace();          }      }      public static void paserXmlByDOM4J(){            long begintime=System.currentTimeMillis();            SAXReader reader=new SAXReader();            try {              Document doc=reader.read(new FileInputStream(new File("students.xml")));              Element root=doc.getRootElement();              System.out.println(root.attributeValue("class")+"--人数--"+root.attributeValue("count"));      /*      List<Node> list=root.selectNodes("student");//需要引入jaxen-1.1.1.jar             for(int i=0,len=list.size();i<len;i++){                 Node node=(Node)list.get(i);                 System.out.println(node.selectSingleNode("name").getText()+"---"+node.selectSingleNode("age").getStringValue());             }*/              Iterator it=root.elementIterator();              Element ele;              while(it.hasNext()){                  ele=(Element)it.next();                  //System.out.println(ele.selectSingleNode("name").getText()+"---"+ele.selectSingleNode("age").getText());                  System.out.println(ele.elementText("name")+"---"+ele.elementText("age"));              }            } catch (FileNotFoundException e) {              e.printStackTrace();          } catch (DocumentException e) {              e.printStackTrace();          }                        System.out.println("sax解析时间(毫秒)"+(System.currentTimeMillis()-begintime));      }  }