dom4j读写xml文件

1. 参考 dom4j-1.6.1\dom4j-1.6.1\docs\guide.html

2. Jom4jTest.java文件

/**
*
*/

package com.jquerypro.test;

import java.io.FileOutputStream;
import java.net.URL;
import java.util.Iterator;
import java.util.List;

import org.dom4j.Attribute;
import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.Node;
import org.dom4j.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

/**
 * @author myhello
 *
 */
public class Jom4jTest {

 private Element rootElm = null; //根结点
 private String FILE_NAME = "com/jquerypro/test/sys-config.xml";
 private Jom4jTest instance = null;
 
 private Jom4jTest(){
  try {
   SAXReader reader = new SAXReader();
   //URL urlFile = Thread.currentThread().getContextClassLoader().getResource(""); //到达class
   Document document = reader.read(Thread.currentThread().getContextClassLoader().getResourceAsStream(FILE_NAME));
   rootElm = document.getRootElement(); 
   System.out.println("根结点名称="+rootElm.getName());
  } catch (Exception e) {
   System.out.println(" 没有找到文件");
  }

 }
 
 public Jom4jTest getInstance(){
  if(instance == null){
   instance = new Jom4jTest();
  }
  return instance;
 }
 // 读取一些信息
 public void getInfo(){

   Node jdbcElm = rootElm.selectSingleNode("//system-config/jdbc-info/driver-name");
   System.out.println("selectNode="+jdbcElm.getText());
  
   //System.out.println(rootElm.asXML());
   //遍历元素
   List nodeList = rootElm.selectNodes("//system-config/beans/bean");
   for ( Iterator it = nodeList.iterator(); it.hasNext(); ) {
    Element elm = (Element)it.next();
   
    System.out.println("元素的内容="+elm.getText());
   
    //属性遍历
    for ( Iterator i = elm.attributeIterator(); i.hasNext(); ) {
              Attribute attribute = (Attribute) i.next();
              System.out.println("元素的属性名和值:"+attribute.getName()+"="+attribute.getStringValue());
       }
   
   } 

 }
 
 //创建document对象 //DocumentHelper
 public Document createDoc(){
   Document document = DocumentHelper.createDocument();
      Element rootElm = document.addElement( "students" );
      Element student1 = rootElm.addElement( "student" )
         .addAttribute( "id", "001" )
         .addAttribute( "username", "hello1" )
         .addText( "学生1" );
    
      Element student2 = rootElm.addElement( "student" )
         .addAttribute( "id", "002" )
         .addAttribute( "username", "hello2" )
         .addText( "学生2" );

      return document;

 }
 
 public void savaXML(String filePath) throws Exception{
  XMLWriter writer = new XMLWriter(new FileOutputStream(filePath));
  Document document = createDoc();
  writer.write(document);
  //查看字符串
  String docStr = document.asXML();
  //System.out.println("docStr="+docStr);
  
      // Pretty print the document to System.out
      OutputFormat format = OutputFormat.createPrettyPrint();  
      format.setEncoding("GBK");
      writer = new XMLWriter( System.out, format );
      writer.write( document );  

 }
 public static void main(String[] args) throws Exception {
  Jom4jTest test= new Jom4jTest();
  test.savaXML("d:/xml_test.xml");
 }
}