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Java生成和解析XML格式文件和字符串(一)

2014-11-24 02:36:13 · 作者: · 浏览: 0
标签: Java 生成 解析 XML 格式 文件 字符串

1、基础知识：

Java解析XML一般有四种方法：DOM、SAX、JDOM、DOM4J。

2、使用介绍

1)、DOM

由W3C(org.w3c.dom)提供的接口，它将整个XML文档读入内存，构建一个DOM树来对各个节点(Node)进行操作。优点就是整个文档都一直在内存中，我们可以随时访问任何节点，并且对树的遍历也是比较熟悉的操作；缺点则是耗内存，并且必须等到所有的文档都读入内存才能进行处理。

(1)示例代码：

  

  
    
    
     
     
      599
      
     
      CMCC
      
     
     
     
      699
      
     
      ChinaNet
      
     
   

  


import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.StringReader;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
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.InputSource;
import org.xml.sax.SAXException;

public class XMLHandler {
    public XMLHandler(){
        
    }
    
    public String createXML(){
        String xmlStr = null;
        DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        try {
            DocumentBuilder builder = factory.newDocumentBuilder();
            Document document = builder.newDocument();
            document.setXmlVersion("1.0");
            
            Element root = document.createElement("root");
            document.appendChild(root);
            
            Element telephone = document.createElement("TelePhone");
            
            Element nokia = document.createElement("type");
            nokia.setAttribute("name", "nokia");
            
            Element priceNokia = document.createElement("price");
            priceNokia.setTextContent("599");
            nokia.appendChild(priceNokia);
            
            Element operatorNokia = document.createElement("operator");
            operatorNokia.setTextContent("CMCC");
            nokia.appendChild(operatorNokia);
            
            telephone.appendChild(nokia);
            
            Element xiaomi = document.createElement("type");
            xiaomi.setAttribute("name", "xiaomi");
            
            Element priceXiaoMi = document.createElement("price");
            priceXiaoMi.setTextContent("699");
            xiaomi.appendChild(priceXiaoMi);
            
            Element operatorXiaoMi = document.createElement("operator");
            operatorXiaoMi.setTextContent("ChinaNet");
            xiaomi.appendChild(operatorXiaoMi);
            
            telephone.appendChild(xiaomi);
            
            root.appendChild(telephone);
            
            TransformerFactory transFactory = TransformerFactory.newInstance();
            Transformer transFormer = transFactory.newTransformer();
            DOMSource domSource = new DOMSource(document);
            
            //export string
            ByteArrayOutputStream bos = new ByteArrayOutputStream();
            transFormer.transform(domSource, new StreamResult(bos));
            xmlStr = bos.toString();
            
            //-------
            //save as file
            File file = new File("TelePhone.xml");
            if(!file.exists()){
                file.createNewFile();
            }
            FileOutputStream out = new FileOutputStream(file);
            StreamResult xmlResult = new StreamResult(out);
            transFormer.transform(domSource, xmlResult);
            //--------
        } catch (ParserConfigurationException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }catch (TransformerConfigurationException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }catch (TransformerException e) {
            // TODO Auto-generated catch block
            e.printStackT