java操作xml增删改查

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