xml解析方式

1.sax

流解析，character函数可能执行多次，数据被截断，用StringBuffer在character方法中拼接字符串，在end方法中取数据才不会断，遇到一个问题，之前这么写的，在windows执行没有问题，但换到linux后有时候character被多次执行

/**
 * 
 */
package com.jiudao.www.util;

import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

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 lenovo0-
 *
 */
public class SaxParseService extends DefaultHandler{
     private List<String> elementsList = null;  
        private String datalogelement = null;  
        private String preTag = null;//作用是记录解析时的上一个节点名称  
          
        public List<String> getElements(InputStream xmlStream) throws Exception{  
            SAXParserFactory factory = SAXParserFactory.newInstance();  
            SAXParser parser = factory.newSAXParser();  
            SaxParseService handler = new SaxParseService();  
            parser.parse(xmlStream, handler);  
            return handler.getDatalogElements();  
        }  
          
        public List<String> getDatalogElements(){  
            return elementsList;  
        }  
          
        @Override  
        public void startDocument() throws SAXException {  
            elementsList = new ArrayList<String>();  
        }  
      
        @Override  
        public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {  
       
            preTag = qName;//将正在解析的节点名称赋给preTag  
        }  
      
        @Override  
        public void endElement(String uri, String localName, String qName)  
                throws SAXException { 
            preTag = null; 
        }  
          
        @Override  
        public void characters(char[] ch, int start, int length) throws SAXException {  
            if(preTag!=null){  
                String content = new String(ch,start,length);
                if(preTag.equals("datalogelement")){
                    elementsList.add(content);
                    //System.out.println("content:"+content);
                }
             }  
//            
        }
        
}

修改后的代码

/**
 * 
 */
package com.jiudao.www.util;

import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

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 lenovo0-
 *
 */
public class SaxParseService extends DefaultHandler{
     private List<String> elementsList = null;  
        private String preTag = null;//作用是记录解析时的上一个节点名称  
        private StringBuilder sb;
        public List<String> getElements(InputStream xmlStream) throws Exception{  
            SAXParserFactory factory = SAXParserFactory.newInstance();  
            SAXParser parser = factory.newSAXParser();  
            SaxParseService handler = new SaxParseService();  
            parser.parse(xmlStream, handler);  
            return handler.getDatalogElements();  
        }  
          
        public List<String> getDatalogElements(){  
            return elementsList;  
        }  
          
        @Override  
        public void startDocument() throws SAXException {  
            elementsList = new ArrayList<String>();  
            sb = new StringBuilder();
        }  
      
        @Override  
        public void startElement(String uri, String localName, String qName, Attributes attributes) throws SAXException {  
       
            preTag = qName;//将正在解析的节点名称赋给preTag  
        }  
      
        @Override  
        public void endElement(String uri, String localName, String qName)  
                throws SAXException { 
            if(qName.equals("datalogelement")){
                elementsList.add(sb.toString());
            }
            preTag = null; 
        }  
          
        @Override  
        public void characters(char[] ch, int start, int length) throws SAXException {  
            if(preTag!=null){  
                String content = new String(ch,start,length);
//                if(preTag.equals("datalogelement")){
//                    elementsList.add(content);
//                    //System.out.println("content:"+content);
//                }
                sb.append(content);
             }  
            
        }
        
}

 

2.dom

把文件加载到内存中，不适用于大文件