String aa = "<row>"+
                      "<user>"+
                        "<userid>1000</userid>"+
                        "<username>aaa</username>"+
                        "</user>"+
                      "<user>"+
                        "<userid>1001</userid>"+
                        "<username>bbb</username>"+
                      "</user>"+
                    "</row>";

这是一个字符串，不是一个XML文档，只是该字符串里面的内容是XML格式，该怎么解析呢？
假如我有一个User对象，有userid和username属性，然后把该字符串里面的数据解析到User对象来。
思路：把该字符串先解析为docment树形文档，然后获取根元素row，再然后获取根元素的第一个子元素user,然后获取user元素的第一个子元素userid并把该值存入user对象里
看代码：

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.dom4j.Document;
import org.dom4j.DocumentException;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;

public class test {    

    /** *//**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub

        String aa = "<row>"+
                      "<user>"+
                        "<userid>1000</userid>"+
                        "<username>aaa</username>"+
                        "</user>"+
                      "<user>"+
                        "<userid>1001</userid>"+
                        "<username>bbb</username>"+
                      "</user>"+
                    "</row>";
        test t = new test();
        List<User> lu = new ArrayList<User>();
        User user = new User();
        lu = t.Analysis(aa, lu, user);
        for(User u : lu){;
            System.out.println(u.getUserid()+"  "+u.getUsername());
        }
    }
    
    public test(){
        
    }
    
    public List<User> Analysis(String s,List<User> lu,User user){
        Document doc = null;             
        try {
            doc = DocumentHelper.parseText(s);// 将字符串转为document树形格式
        } catch (DocumentException e) {
            e.printStackTrace();
        }         
        Element rootElt = doc.getRootElement(); // 获取根节点
        Iterator iter = rootElt.elementIterator("user"); // 获取根节点下的子节点user
        while (iter.hasNext()) {
            user = new User();
            Element recordEle = (Element) iter.next();
            Iterator iters = recordEle.elementIterator("userid"); // 获取子节点user下的子节点userId
            while(iters.hasNext()){
                Element userId = (Element) iters.next();
                user.setUserid(Long.parseLong(userId.getText()));
            }
            iters = recordEle.elementIterator("username"); // 获取子节点user下的子节点username
            while(iters.hasNext()){
                Element username = (Element) iters.next();
                user.setUsername(username.getText());
            }
            lu.add(user);
        } 
        return lu;
    }

}

class User {
    private Long userid;
    private String username;
    public Long getUserid() {
        return userid;
    }
    public void setUserid(Long userid) {
        this.userid = userid;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }    
}

整个解析过程及思路在Analysis方法里面，注释写清楚了，可以自己去琢磨！

  <groupId>com.loubing.test</groupId>
  <artifactId>myhibernate</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>myhibernate</name>
<!--依赖包来源，这里是我自己建立的一个私服。也可以用https://repo1.maven.org/maven2/  -->
  <url>http://localhost:10000/nexus/content/groups/public</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
    <!-- hibernate -->
    <dependency>
 <groupId>c3p0</groupId>
 <artifactId>c3p0</artifactId>
 <version>0.9.1.2</version>
  </dependency>
            
   <!-- 添加Hibernate依赖 -->   
    <dependency> 
      <groupId>org.hibernate</groupId> 
      <artifactId>hibernate3</artifactId> 
      <version>3.0.2</version> 
    </dependency> 
    <!--以下的包其实可以用hibernate-core，但是我觉得太多了，根据需要，就把几个重要的单独添加进来-->
    <dependency>
        <groupId>org.hibernate.javax.persistence</groupId>
        <artifactId>hibernate-jpa-2.0-api</artifactId>
        <version>1.0.1.Final</version>
    </dependency>
    <dependency>
     <groupId>commons-collections</groupId>
     <artifactId>commons-collections</artifactId>
     <version>3.1</version>
 </dependency>
 <dependency>
     <groupId>javax.transaction</groupId>
     <artifactId>jta</artifactId>
     <version>1.1</version>
 </dependency>
    <dependency>   
        <groupId>dom4j</groupId>   
        <artifactId>dom4j</artifactId>   
        <version>1.1</version>
    </dependency>
    <dependency>   
        <groupId>org.slf4j</groupId>   
        <artifactId>slf4j-api</artifactId>   
        <version>1.4.2</version>
    </dependency>
    <dependency>   
        <groupId>org.slf4j</groupId>   
        <artifactId>slf4j-log4j12</artifactId>   
        <version>1.4.2</version>
    </dependency>
    <dependency>   
        <groupId>javassist</groupId>   
        <artifactId>javassist</artifactId>   
        <version>3.11.0.GA</version>
    </dependency>
    <!-- 添加oracle10g jdbc driver --> 
    <dependency>   
        <groupId>com.oracle</groupId>   
        <artifactId>ojdbc14</artifactId>   
        <version>10.2.0.1.0</version>
    </dependency>
  </dependencies>
</project>