package hdu.terence.dao; 
import java.util.List; 
import hdu.terence.bean.Message; 
public interface IMessage { 
    publicList<Message> queryMessageList(Message message); 
} 

<?xml version="1.0"encoding="UTF-8"?> 
<!DOCTYPE mapper 
  PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" 
  "http://mybatis.org/dtd/mybatis-3-mapper.dtd"> 
<mapper namespace="com.terence.dao.IMessage">  
 <resultMap type="hdu.terence.bean.Message" id="MessageResult">  
  <id column="id" jdbcType="INTEGER"property="id"/> <!--主键标签--> 
  <result column="COMMAND" jdbcType="VARCHAR"property="command"/> 
  <result column="DESCRIPTION" jdbcType="VARCHAR" property="description"/> 
  <result column="CONTENT" jdbcType="VARCHAR"property="content"/> 
 </resultMap>   
 <select id="queryMessageList" parameterType="hdu.terence.bean.Message" resultMap="MessageResult"> 
  SELECTID,COMMAND,DESCRIPTION,CONTENT FROM message WHERE 1=1    
  <if test="command!=null and!"".equals(command.trim())"> 
  andCOMMAND=#{command} 
  </if> 
  <if test="description!=null and!"".equals(description.trim())"> 
  andDESCRIPTION like '%' #{description} '%' 
  </if>  
 </select><span style="color: teal; font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);"> </span> 

public List<Message> queryMessageListByMybatis(Stringcommand,String description) 
  { 
    DBAccess dbAccess =new DBAccess(); 
    SqlSession sqlSession=null; 
    List<Message>messageList=new ArrayList<Message>(); 
    try { 
      sqlSession=dbAccess.getSqlSession(); 
      Message message=new Message(); 
      message.setCommand(command); 
      message.setDescription(description);           
      //方式二：通过接口调用配置文件里面的sql语句 
      IMessageimessage=sqlSession.getMapper(IMessage.class); 
      messageList=imessage.queryMessageList(message); 
    } catch (IOException e) { 
      e.printStackTrace(); 
    } 
    finally{ 
      if(sqlSession!=null) 
      { 
        sqlSession.close(); //要关闭数据库会话 
      } 
    } 
    return messageList; 
  } 

MapperProxy implements InvocationHandler
{
 MapperProxy.invoke();
}

sqlSession.getMapper()==Proxy.newProxyInstance(); 
IMessage imessage=sqlSession.getMapper(IMessage.class);
messageList=imessage.queryMessageList(message);

public SqlSession getSqlSession() throws IOException 
{ 
    //1、通过配置文件获取数据库连接相关信息 
    Readerreader=Resources.getResourceAsReader("hdu/terence/config/Configuration.xml"); 
    //2、通过配置信息构建SqlSessionFactory 
    SqlSessionFactorySSF=newSqlSessionFactoryBuilder().build(reader); 
    //3、通过SqlSessionFactory打开数据库会话 
    SqlSessionsqlSession=SSF.openSession(); 
    return sqlSession; }