java解析Xml

java中XML格式的字符串4读取方式的简单比较

 

1.java自带的DOM解析. 

import java.io.StringReader;   

import javax.xml.parsers.DocumentBuilder;   

import javax.xml.parsers.DocumentBuilderFactory;   

import org.w3c.dom.Document;   

import org.w3c.dom.Element;   

import org.w3c.dom.Node;   

import org.w3c.dom.NodeList;   

import org.xml.sax.InputSource;   

  

public class ReaderXmlForDOM {   

  

    public static void main(String args[]) {   

          String text ="<XML><A>123</A><B>whl123</B><C>亮亮</C><D>1</D><E>1</E><F>165074</F><G>贫穷</G><H>1698.0</H><I>初级士官</I><J>湖南</J><K>常德</K><L>1</L></XML>"  

            

         long begin = System.currentTimeMillis();   

          parse( text );   

         long after = System.currentTimeMillis();   

          System.out.println("DOM用时"+(after-begin)+"毫秒");   

         }   

       

    public static void parse(String protocolXML) {   

            

        try {   

             DocumentBuilderFactory factory = DocumentBuilderFactory   

                     .newInstance();   

             DocumentBuilder builder = factory.newDocumentBuilder();   

             Document doc = builder   

                     .parse(new InputSource(new StringReader(protocolXML)));   

  

             Element root = doc.getDocumentElement();   

             NodeList books = root.getChildNodes();   

            if (books != null) {   

                for (int i = 0; i < books.getLength(); i++) {   

                     Node book = books.item(i);   

                     System.out.println("节点=" + book.getNodeName() + "\ttext="  

                             + book.getFirstChild().getNodeValue());   

                 }   

             }   

         } catch (Exception e) {   

             e.printStackTrace();   

         }   

     }   

}  

我当时dom解析用时是个不稳定的值在62-78毫秒之间. 

以下的三种方法mian方法里面都是一样的解析那段字符串,记录用时,就不在贴出, 只贴出所用的解析部分 

2.java自带的SAX解析. 

import javax.xml.parsers.SAXParser;   

import javax.xml.parsers.SAXParserFactory;   

import org.xml.sax.InputSource;   

import org.xml.sax.SAXException;   

import org.xml.sax.helpers.DefaultHandler;   

  

public class ReaderXmlForSAX {   

public static void parse(String protocolXML) {   

            

        try {   

             SAXParserFactory saxfac = SAXParserFactory.newInstance();      

             SAXParser saxparser = saxfac.newSAXParser();   

             TestSAX   tsax = new TestSAX();   

             saxparser.parse(new InputSource(new StringReader(protocolXML)),tsax);   

         } catch (Exception e) {   

             e.printStackTrace();   

         }   

     }   

}   

  

class TestSAX extends DefaultHandler{   

       

    private StringBuffer buf;   

    private String str;   

    public TestSAX(){   

         super();   

     }   

        

    public void startDocument() throws SAXException{   

         buf=new StringBuffer();   

         System.out.println("*******开始解析XML*******");   

     }   

       

    public void endDocument() throws SAXException{           

         System.out.println("*******XML解析结束*******");   

     }   

        

    public void endElement(String namespaceURI,String localName,String fullName )throws SAXException{   

         str = buf.toString();   

         System.out.println("节点="+fullName+"\tvalue="+buf+" 长度="+buf.length());   

         System.out.println();   

         buf.delete(0,buf.length());   

       }   

       

    public void characters( char[] chars, int start, int length )throws SAXException{   

        //将元素内容累加到StringBuffer中   

         buf.append(chars,start,length);   

     }   

}  

SAX用时是62毫秒,最快的.但是需要多写一个类 

3.DOM4J解析,需要下载对应的jar包 

import java.util.Iterator;   

import java.util.List;   

import org.dom4j.Document;   

import org.dom4j.DocumentHelper;   

import org.dom4j.Element;   

  

public class ReaderXmlForDOM4J {   

//DOM4j解析XML   

    public static void parse(String protocolXML) {   

           

        try {   

  

             Document doc=(Document)DocumentHelper.parseText(protocolXML);   

             Element books = doc.getRootElement();   

             System.out.println("根节点"+books.getName());   

            // Iterator users_subElements = books.elementIterator("UID");//指定获取那个元素   

             Iterator   Elements = books.elementIterator();   

            while(Elements.hasNext()){   

                Element user = (Element)Elements.next();   

                System.out.println("节点"+user.getName()+"\ttext="+user.getText());   

                List   subElements = user.elements();   

            //    List user_subElements = user.elements("username");指定获取那个元素   

//              System.out.println("size=="+subElements.size());   

//              for( int i=0;i<subElements.size();i++){   

//                  Element ele = (Element)subElements.get(i);   

//                  System.out.print(ele.getName()+" : "+ele.getText()+" ");   

//              }   

                System.out.println();   

            }   

         } catch (Exception e) {   

             e.printStackTrace();   

         }           

     }   

}  

DOM4J的用时为140毫秒,慢 并且还需要单独的jar包 

4.JDOM解析,需要下载对应的jar包 

import java.io.StringReader;   

import java.util.List;   

import org.jdom.Document;   

import org.jdom.Element;   

import org.jdom.input.SAXBuilder;   

import org.xml.sax.InputSource;   

  

public class ReaderXmlForJDOM {   

public static void parse(String protocolXML) {   

         SAXBuilder builder=new SAXBuilder(false);   

        try {   

             Document doc = builder.build(new InputSource(new StringReader(protocolXML)));   

             Element eles = doc.getRootElement(); // 得到根元素   

             System.out.println("根节点"+eles.getName());   

               

             List<Element> list = eles.getChildren(); // 得到元素的集合   

            //List studentList = students.getChildren("student"); // 得到指定元素（节点）的集合   

  

            if( list!=null){   

                for (int i = 0; i < list.size(); i++) {   

                     Element book = (Element)list.get(i);   

                     System.out.println("节点=" + book.getName() + "\ttext="  

                             + book.getValue());   

                 }   

              }   

             } catch (Exception e) {   

             e.printStackTrace();   

         }   

     }   

}  

JDOM的用时为125毫秒,比较慢 并且还需要单独的jar包