java操作xml（sax，dom，jdom，dom4j）增删改查

java操作xml主要是有四种方式：dom，sax，jdom，dom4j。这四种方式各有优缺点：（以下比较是来自网络）

1：DOM4J性能最好，连Sun的JAXM也在用DOM4J.目前许多开源项目中大量采用DOM4J，例如大名鼎鼎的Hibernate也用DOM4J来读取XML配置文件。如果不考虑可移植性，那就采用DOM4J.

2：JDOM 和DOM在性能测试时表现不佳，在测试10M文档时内存溢出。在小文档情况下还值得考虑使用DOM和JDOM.虽然JDOM的开发者已经说明他们期望在正式发行版前专注性能问题，但是从性能观点来看，它确实没有值得推荐之处。另外，DOM仍是一个非常好的选择。DOM实现广泛应用于多种编程语言。它还是许多其它与XML相关的标准的基础，因为它正式获得W3C推荐（与基于非标准的Java模型相对），所以在某些类型的项目中可能也需要它（如在 JavaScript中使用DOM）。

3：SAX表现较好，这要依赖于它特定的解析方式－事件驱动。一个SAX检测即将到来的XML 流，但并没有载入到内存（当然当XML流被读入时，会有部分文档暂时隐藏在内存中）。

接下来我来展示以下用这四种方式处理xml的一个简单的例子，希望能给大家一些帮助。

1：要操作的xml文件：student.xml

<?xml version="1.0" encoding="UTF-8" ?> 
<students> 
<student> 
  <name>TigerLee</name> 
  <age>26</age> 
  <sex>男</sex> 
  <address>北京海淀</address> 
  </student> 
<student> 
  <name>Snow</name> 
  <age>24</age> 
  <sex>女</sex> 
  <address>山东</address> 
  </student> 
</students> 

2：处理xml的java类HandleXML.java

package com.tigerlee.xml; 

import java.io.File; 
import java.io.FileWriter; 
import java.io.Writer; 
import java.util.Iterator; 
import java.util.LinkedHashMap; 
import java.util.List; 
import java.util.Map; 
import java.util.Set; 
import java.util.Stack; 

import javax.xml.parsers.DocumentBuilder; 
import javax.xml.parsers.DocumentBuilderFactory; 
import javax.xml.transform.Transformer; 
import javax.xml.transform.TransformerFactory; 
import javax.xml.transform.dom.DOMSource; 
import javax.xml.transform.stream.StreamResult; 

import org.dom4j.Element; 
import org.dom4j.io.OutputFormat; 
import org.dom4j.io.SAXReader; 
import org.dom4j.io.XMLWriter; 
import org.w3c.dom.Document; 
import org.w3c.dom.Node; 
import org.w3c.dom.NodeList; 
import org.xml.sax.Attributes; 
import org.xml.sax.SAXException; 
import org.xml.sax.helpers.DefaultHandler; 

/** 
* 
* 在XML文档中实现增、删、改、查 
* @author TigerLee 
* 
*/ 
public class HandleXML { 

/** 
  * 采用DOM方式 
  * @author TigerLee 
  * 
  */ 
public class DOMForXml{ 
  /** 
   * 获得doc对象 
   * @param fileName 
   * @return 
   */ 
  public Document getDocument(String fileName){ 
   Document document = null; 
   try{ 
    DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance(); 
    DocumentBuilder builder = factory.newDocumentBuilder(); 
    document = builder.parse(new File(fileName)); 
    
   }catch(Exception e){ 
    e.printStackTrace(); 
   } 
   
   return document; 
  } 
  /** 
   * 将改动持久到文件 
   * @param doc 
   * @param distFileName 
   */ 
  public void modifyFile(Document doc,String distFileName){ 
   try{ 
    TransformerFactory tf = TransformerFactory.newInstance(); 
    Transformer tfer = tf.newTransformer(); 
    DOMSource dsource = new DOMSource(doc); 
    StreamResult sr = new StreamResult(new File("student.xml")); 
    tfer.transform(dsource, sr); 
   }catch(Exception e){ 
    e.printStackTrace(); 
   } 
   
  } 
  /** 
   * 解析 
   * @param fileName 
   */ 
  public void paseXml(String fileName){ 
   Document document = getDocument(fileName); 
   NodeList nodeList = document.getElementsByTagName("student"); 
   for(int i=0;i<nodeList.getLength();i++){ 
    StringBuilder sb = new StringBuilder(); 
    sb.append("姓名："+document.getElementsByTagName("name").item(i).getFirstChild().getNodeValue()); 
    sb.append(" , "); 
    sb.append("年龄："+document.getElementsByTagName("age").item(i).getFirstChild().getNodeValue()); 
    sb.append(" , "); 
    sb.append("性别："+document.getElementsByTagName("sex").item(i).getFirstChild().getNodeValue()); 
    sb.append(" , "); 
    sb.append("地址："+document.getElementsByTagName("address").item(i).getFirstChild().getNodeValue()); 
    
    System.out.println(sb.toString()); 
   } 
  } 
  /** 
   * 创建一个新的学生 
   * @param name 
   * @param age 
   * @param sex 
   * @param address 
   */ 
  public void addNewNode(String name,String age,String sex,String address){ 
   try{ 
    Document document = getDocument("student.xml"); 
    NodeList nodeList = document.getElementsByTagName("students"); 
    //创建新的节点 
    Node studentNode = document.createElement("student"); 
    Node nameNode = document.createElement("name"); 
    nameNode.appendChild(document.createTextNode(name)); 
    Node ageNode = document.createElement("age"); 
    ageNode.appendChild(document.createTextNode(age)); 
    Node sexNode = document.createElement("sex"); 
    sexNode.appendChild(document.createTextNode(sex)); 
    Node addressNode = document.createElement("address"); 
    addressNode.appendChild(document.createTextNode(address)); 
    // 添加节点 
    studentNode.appendChild(nameNode); 
    studentNode.appendChild(ageNode); 
    studentNode.appendChild(sexNode); 
    studentNode.appendChild(addressNode); 
    nodeList.item(0).appendChild(studentNode); 
    // 此时真正的处理将新数据添加到文件中（磁盘） 
    TransformerFactory tf = TransformerFactory.newInstance(); 
    Transformer tfer = tf.newTransformer(); 
    DOMSource dsource = new DOMSource(document); 
    StreamResult sr = new StreamResult(new File("student.xml")); 
    tfer.transform(dsource, sr); 
   }catch(Exception e){ 
    e.printStackTrace(); 
   } 
   
   paseXml("student.xml"); 
  } 
  /** 
   * 删除一个节点 
   * @param name 
   */ 
  public void deleteNode(String name){ 
   Document document = getDocument("student.xml"); 
   
   NodeList nodeList = document.getElementsByTagName("name"); 
   for(int i=0;i<nodeList.getLength();i++){ 
    String value = nodeList.item(i).getFirstChild().getTextContent(); 
    if(name!=null && name.equalsIgnoreCase(value)){ 
     Node parentNode = nodeList.item(i).getParentNode(); 
     document.getFirstChild().removeChild(parentNode); 
    } 
   } 
   modifyFile(document,"student.xml"); 
  } 
  /** 
   * 根据name修改某个节点的内容 
   * @param name 
   */ 
  public void updateNode(String name){ 
           
   Document document = getDocument("student.xml"); 
   NodeList nodeList = document.getElementsByTagName("name"); 
   for(int i=0;i<nodeList.getLength();i++){ 
    String value = nodeList.item(i).getFirstChild().getTextContent(); 
    if(name!=null && name.equalsIgnoreCase(value)){ 
     Node parentNode = nodeList.item(i).getParentNode(); 
     NodeList nl = parentNode.getChildNodes(); 
     for(int j=0;j<nl.getLength();j++){ 
      String modifyNode= nl.item(j).getNodeName(); 
      if(modifyNode.equalsIgnoreCase("age")){ 
       nl.item(j).getFirstChild().setTextContent("25"); 
      } 
     } 
    } 
   } 
   modifyFile(document,"student.xml"); 
  } 
  
  
} 
/** 
  * 采用SAX方式 
  * @author TigerLee 
  * 
  */ 
public class SAXForXml extends DefaultHandler{ 
  private Stack tags = new Stack(); 
  private Map contents = new LinkedHashMap(); 
  public  int count = 0; 
  @Override 
  public void characters(char[] ch, int start, int length) 
    throws SAXException { 
   String tag = (String)tags.peek(); 

   if("name".equals(tag)){ 
    String name = new String(ch,start,length); 
     contents.put("name"+count,name); 
   } 
   if("age".equals(tag)){ 
    contents.put("age"+count,new String(ch,start,length)); 
   } 
   if("sex".equals(tag)){ 
    contents.put("sex"+count,new String(ch,start,length)); 
   } 
   if("address".equals(tag)){ 
    contents.put("address"+count,new String(ch,start,length)); 
   } 
  } 

  @Override 
  public void startElement(String uri, String localName, String qName, 
    Attributes attributes) throws SAXException { 
   if("student".equals(qName)){ 
    count++; 
   } 
   tags.push(qName); 
  } 
  
  @Override 
  public void endElement(String uri, String localName, String qName) 
    throws SAXException { 
   tags.pop(); 
  } 

  public Map getContents(){ 
   return contents; 
  } 
} 

/** 
  * 采用JDOM方式 
  * @author TigerLee 
  * 
  */ 
public class JDOMForXml{ 
  
} 

/** 
  * 采用DOM4J方式 
  * @author TigerLee 
  * 
  */ 
public class DOM4JForXml{ 
  /** 
   * 获取doc对象（org.dom4j.Document） 
   * @param fileName 
   * @return 
   */ 
  public org.dom4j.Document getDocument(String fileName){ 
   SAXReader sr = new SAXReader(); 
   org.dom4j.Document doc = null; 
   try { 
    
    doc = sr.read(new File(fileName)); 
    
   } catch (Exception e) { 
    
    e.printStackTrace(); 
   } 
   return doc; 
  } 
  /** 
   * 将文件保存到硬盘 
   * @param doc 
   * @param fileName 
   */ 
  public void writeToFile(org.dom4j.Document doc,String fileName){ 
   try { 
    Writer writer = new FileWriter(fileName); 
    OutputFormat format = OutputFormat.createPrettyPrint(); 
    format.setEncoding("UTF-8"); 
    XMLWriter xmlWriter = new XMLWriter(writer, format); 
    xmlWriter.write(doc); 
    xmlWriter.close(); 
    System.out.println(" 文件已经钝化！"); 
   } catch (Exception e) { 
    
    e.printStackTrace(); 
   } 
  } 
  
  /** 
   * 遍历xml文件输出节点值 
   * 
   * @param fileName 
   */ 
  public void readXml(String fileName){ 
   org.dom4j.Document doc = getDocument(fileName); 
   List nameList = doc.selectNodes("/students/student/name"); 
   List ageList = doc.selectNodes("/students/student/age"); 
   List sexList = doc.selectNodes("/students/student/sex"); 
   List addressList = doc.selectNodes("/students/student/address"); 
   for(int i=0;i<nameList.size();i++){ 
    StringBuilder sb = new StringBuilder(); 
    sb.append("name="+((Element)nameList.get(i)).getTextTrim()); 
    sb.append(",age="+((Element)ageList.get(i)).getTextTrim()); 
    sb.append(",sex="+((Element)sexList.get(i)).getTextTrim()); 
    sb.append(",address="+((Element)addressList.get(i)).getTextTrim()); 
    System.out.println(sb.toString()); 
   } 
   
  } 
  /** 
   * 根据姓名修改一个学生的信息 
   * @param name 
   * @param newValue 
   * @param fileName 
   */ 
  public void updateXml(String name,Map newValue,String fileName){ 
   org.dom4j.Document doc = getDocument(fileName); 
   List nameList = doc.selectNodes("/students/student/name"); 
   Iterator iterator = nameList.iterator(); 
   
   while(iterator.hasNext()){ 
    Element element = (Element)iterator.next(); 
    
    if(name!=null && name.equals(element.getText())){ 
     Element pe = element.getParent(); 
     List childList = pe.elements(); 
     for(int i=0;i<childList.size();i++){ 
      Iterator valueSet = newValue.entrySet().iterator(); 
      while(valueSet.hasNext()){ 
       Map.Entry entry = (Map.Entry)valueSet.next(); 
       String nodeName = ((Element)childList.get(i)).getName(); 
       String key = entry.getKey().toString(); 
       if(key!=null && key.equals(nodeName)){ 
        ((Element)childList.get(i)).setText((String)entry.getValue()); 
       } 
      } 
     } 
    } 
   } 
   writeToFile(doc, fileName); 
  } 
  
} 


} 

3:接下来是测试的java文件 TestXml.java

package com.tigerlee.xml; 

import java.io.File; 
import java.util.HashMap; 
import java.util.Iterator; 
import java.util.Map; 
import java.util.Set; 

import javax.xml.parsers.SAXParserFactory; 

import org.junit.Test; 


public class TestXml{ 

@Test 
public void testDomForXml(){ 
  
  HandleXML handleXml = new HandleXML(); 
  HandleXML.DOMForXml domForXml = handleXml.new DOMForXml(); 
  //解析 
  //domForXml.paseXml("student.xml"); 
  // 新增 
  //domForXml.addNewNode("Sun", "20", "Man", "USA"); 
  //删除 
  //domForXml.deleteNode("sun"); 
  domForXml.updateNode("TigerLee"); 
} 
@Test 
public void testSAXForXml() throws Exception{ 
  HandleXML handleXml = new HandleXML(); 
  HandleXML.SAXForXml saxForXml = handleXml.new SAXForXml(); 
  SAXParserFactory saxFactory = SAXParserFactory.newInstance(); 
  javax.xml.parsers.SAXParser sp = saxFactory.newSAXParser(); 
  sp.parse(new File("student.xml"), saxForXml); 
  Map contents = saxForXml.getContents(); 
  Iterator keys = contents.keySet().iterator(); 
  while(keys.hasNext()){ 
   String key = (String)keys.next(); 
   System.out.println(key+":"+contents.get(key)); 
  } 
} 
@Test 
public void testDom4jForXml(){ 
  HandleXML handleXml = new HandleXML(); 
  HandleXML.DOM4JForXml dom4j = handleXml.new DOM4JForXml(); 
  //解析xml 
  dom4j.readXml("student.xml"); 
  
  Map newValue = new HashMap(); 
  newValue.put("age","26"); 
  dom4j.updateXml("TigerLee", newValue, "student.xml"); 
} 


} 

以上是自己总结的一些处理xml的方式，~~在处理xml的类中使用了内部类，测试类使用的是简单的单元测试方式。

例子中使用的jar包：

dom.jar

xercesImpl.jar

dom4j-1.6.1.jar

jaxen-1.1.1.jar