import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.Node;
import org.dom4j.io.SAXReader;
public class Dom4jParseDemo {

 public static void main(String[] args) {
     String xml="";
  xml+="<?xml version=\"1.0\" encoding=\"UTF-8\"?>";
  xml+="<root>";
  xml+="<users userId=\"1\">";
  xml+="<username>admin</username>";
  xml+="<password>111</password>";
  xml+="<quanxian>0</quanxian>";
  xml+="<underling><name>under1</name></underling>";
  xml+="</users>";
  
  xml+="<users userId=\"2\">";
  xml+="<username>hehe</username>";
  xml+="<password>张三</password>";
  xml+="<quanxian>1</quanxian>";
  xml+="<underling><name>under1</name></underling>";
  xml+="</users>";
  
  xml+="<users userId=\"3\">";
  xml+="<username>李鹏</username>";
  xml+="<password>111</password>";
  xml+="<quanxian>2</quanxian>";
  xml+="<underling><name>under1</name></underling>";
  xml+="</users>";
  
  xml+="<users userId=\"4\">";
  xml+="<username>java</username>";
  xml+="<password>111</password>";
  xml+="<quanxian>1</quanxian>";
  xml+="<underling><name>under1</name></underling>";
  xml+="</users>";
  xml+="</root>";
  SAXReader saxReader = new SAXReader();
  try {
   //File file=new File("C:\\test.xml");
   //FileInputStream in=new FileInputStream(file);
   //Document document = saxReader.read(in);//从文件流读入xml数据
   StringBufferInputStream strInStream=new StringBufferInputStream(xml);
   Document document = saxReader.read(strInStream);//从STRING对象读入XML数据
   Element root = document.getRootElement();
   List listUsers=root.selectNodes("users");
   for(int i=0;i<listUsers.size();i++){
    Element eleUser=(Element)listUsers.get(i);
    Node nodeUsername=eleUser.selectSingleNode("username");
    Node nodePassword=eleUser.selectSingleNode("password");
    
    System.err.println("username:"+nodeUsername.getText());
    System.err.println("password:"+nodeUsername.getText());
    
    //System.err.println("username:"+nodeUsername.getStringValue());
    //System.err.println("password:"+nodePassword.getStringValue());
   }
  } catch (Exception e) {
   e.printStackTrace();
  }
 }
}
 //示例2
package dom4jdemo;

import java.io.File;
import java.io.FileWriter;
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.io.OutputFormat;
import org.dom4j.io.SAXReader;
import org.dom4j.io.XMLWriter;

public class Dom4jUpdateDemo {

    public int createXMLFile(String filename){

       /** 返回操作结果, 0表失败, 1表成功 */

       int returnValue = 0;

       /** 建立document对象 */

       Document document = DocumentHelper.createDocument();

       /** 建立XML文档的根books */

       Element booksElement = document.addElement("books");

       /** 加入一行注释 */

       booksElement.addComment("This is a test for dom4j, holen, 2004.9.11");

       /** 加入第一个book节点 */

       Element bookElement = booksElement.addElement("book");

       /** 加入show属性内容 */

       bookElement.addAttribute("show","yes");

       /** 加入title节点 */

       Element titleElement = bookElement.addElement("title");

       /** 为title设置内容 */

       titleElement.setText("Dom4j Tutorials");

       /** 类似的完成后两个book */

       bookElement = booksElement.addElement("book");

       bookElement.addAttribute("show","yes");

       titleElement = bookElement.addElement("title");

       titleElement.setText("Lucene Studing");

       bookElement = booksElement.addElement("book");

       bookElement.addAttribute("show","no");

       titleElement = bookElement.addElement("title");

       titleElement.setText("Lucene in Action");

       /** 加入owner节点 */

       Element ownerElement = booksElement.addElement("owner");

       ownerElement.setText("O'Reilly");

       try{

           /** 将document中的内容写入文件中 */

           XMLWriter writer = new XMLWriter(new FileWriter(new File(filename)));

           writer.write(document);

           writer.close();

           /** 执行成功,需返回1 */

           returnValue = 1;

       }catch(Exception ex){

           ex.printStackTrace();

       }

       return returnValue;

    }

    /**

     * 修改XML文件中内容,并另存为一个新文件

     * 重点掌握dom4j中如何添加节点,修改节点,删除节点

     * @param filename 修改对象文件

     * @param newfilename 修改后另存为该文件

     * @return 返回操作结果, 0表失败, 1表成功

     */

    public int ModiXMLFile(String filename,String newfilename){

       int returnValue = 0;

       try{

           SAXReader saxReader = new SAXReader();

           Document document = saxReader.read(new File(filename));

           /** 修改内容之一: 如果book节点中show属性的内容为yes,则修改成no */

           /** 先用xpath查找对象 */

           List list = document.selectNodes("/books/book/@show" );

           Iterator iter = list.iterator();

           while(iter.hasNext()){

              Attribute attribute = (Attribute)iter.next();

              if(attribute.getValue().equals("yes")){

                  attribute.setValue("no");

              }  

           }

           /**

            * 修改内容之二: 把owner项内容改为Tshinghua

            * 并在owner节点中加入date节点,date节点的内容为2004-09-11,还为date节点添加一个属性type

            */

           list = document.selectNodes("/books/owner" );

           iter = list.iterator();

           if(iter.hasNext()){

              Element ownerElement = (Element)iter.next();

              ownerElement.setText("Tshinghua");

              Element dateElement = ownerElement.addElement("date");

              dateElement.setText("2004-09-11");

              dateElement.addAttribute("type","Gregorian calendar");

           }

           /** 修改内容之三: 若title内容为Dom4j Tutorials,则删除该节点 */

           list = document.selectNodes("/books/book");

           iter = list.iterator();

           while(iter.hasNext()){

              Element bookElement = (Element)iter.next();

              Iterator iterator = bookElement.elementIterator("title");

               while(iterator.hasNext()){

                  Element titleElement=(Element)iterator.next();

                  if(titleElement.getText().equals("Dom4j Tutorials")){

                     bookElement.remove(titleElement);

                  }

              }

           }         

           try{

              /** 将document中的内容写入文件中 */

              XMLWriter writer = new XMLWriter(new FileWriter(new File(newfilename)));

              writer.write(document);

              writer.close();

              /** 执行成功,需返回1 */

              returnValue = 1;

           }catch(Exception ex){

              ex.printStackTrace();

           }

       }catch(Exception ex){

           ex.printStackTrace();

       }

       return returnValue;

    }

    /**

     * 格式化XML文档,并解决中文问题

     * @param filename

     * @return

     */

    public int formatXMLFile(String filename){

       int returnValue = 0;

       try{

           SAXReader saxReader = new SAXReader();

           Document document = saxReader.read(new File(filename));

           XMLWriter writer = null;

           /** 格式化输出,类型IE浏览一样 */

           OutputFormat format = OutputFormat.createPrettyPrint();

           /** 指定XML编码 */

           format.setEncoding("GBK");

           writer= new XMLWriter(new FileWriter(new File(filename)),format);

           writer.write(document);

           writer.close();     

           /** 执行成功,需返回1 */

           returnValue = 1;    

       }catch(Exception ex){

           ex.printStackTrace();

       }

       return returnValue;

    }

        public static void main(String[] args) {

            Dom4jUpdateDemo temp = new Dom4jUpdateDemo();

           System.out.println(temp.createXMLFile("c://holen.xml"));   
           System.out.println(temp.ModiXMLFile("c://holen.xml","c://holen2.xml"));

           System.out.println(temp.formatXMLFile("c://holen2.xml"));

        }

}
//示例3
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.DocumentHelper;
import org.dom4j.io.XMLWriter;

public class Dom4JWriteDemo2 {

    public static void main(String[] args) {
       
        String usernames[]={"admin","zhong","yang"};
        String passwords[]={"1984","123","321"};
       
        Document doc = DocumentHelper.createDocument();

        Element root = doc.addElement("root");
       
        for (int i = 0; i < usernames.length; i++) {
            Element users = root.addElement("users");
            users.addAttribute("userId", String.valueOf(i));
            Element username = users.addElement("username");
            username.setText(usernames[i]);
            Element password = users.addElement("password");
            password.setText(passwords[i]);
        }

        try {
            XMLWriter output = new XMLWriter(new FileWriter(new File("c:/Dom4j.xml")));
            output.write(doc);
            output.close();

            System.out.println("XML创建成功!");
        } catch (IOException e) {
            System.out.println("XML创建失败!" + e.getMessage());
        }
    }
}