原始dao的开发方法（程序员需要写dao接口和dao实现类）

dao接口

package cn.iven.mybatis.dao;
/**
 * dao接口实现
 */
import cn.iven.mybatis.po.User;

public interface UserDao {

    //根据id查询用户信息
    public User findUserById(int id) throws Exception;
    
    //添加用户信息
    public void  insertUser(User user) throws Exception;
    
    //删除用户信息
    public void deleteUser(int id) throws Exception;
}

dao实现类

package cn.iven.mybatis.dao;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;

/**
 * dao接口实现类
 */
import cn.iven.mybatis.po.User;

public class UserDaoImpl implements UserDao{

    //需要向dao实现类中注入SqlSessionFactory
    //这里通过构造方法注入
    private SqlSessionFactory sqlSessionFactory;
    public UserDaoImpl(SqlSessionFactory sqlSessionFactory) {
        this.sqlSessionFactory = sqlSessionFactory;
    }
    
    @Override
    public User findUserById(int id) throws Exception {
        SqlSession sqlSession = sqlSessionFactory.openSession();
        
        User user = sqlSession.selectOne("test.findUserById", id);
        
        //释放资源
        sqlSession.close();
        
        return user;
    }

    @Override
    public void insertUser(User user) throws Exception {

        SqlSession sqlSession = sqlSessionFactory.openSession();
        
        //执行插入操作
        sqlSession.insert("test.insertUser", user);
        
        //事务提交
        sqlSession.commit();
        
        //释放资源
        sqlSession.close();
    }

    @Override
    public void deleteUser(int id) throws Exception {
        
        SqlSession sqlSession = sqlSessionFactory.openSession();
        
        //执行插入操作
        sqlSession.delete("test.deleteUser", id);
        
        //事务提交
        sqlSession.commit();
        
        //释放资源
        sqlSession.close();
        
    }

}

Test

package cn.iven.mybatis.dao;

import java.io.InputStream;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Before;
import org.junit.Test;

import cn.iven.mybatis.po.User;

public class UserDaoImplTest {

    private SqlSessionFactory sqlSessionFactory;
    
    //此方法在执行testFindUserById()之前执行
    @Before
    public void setUp() throws Exception{
        //mybatis配置文件
        String resource = "SqlMapConfig.xml";
        //得到配置文件流
        InputStream inputStream = Resources.getResourceAsStream(resource);
        
        //创建会话工厂，传入mybatis的配置信息
        sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
    }
    
    @Test
    public void testFindUserById() throws Exception {
        
        //创建UserDao的对象
        UserDao userDao = new UserDaoImpl(sqlSessionFactory);
        
        //调用UserDao的方法
        User user = userDao.findUserById(28);
        
        System.out.println(user);
    }

}