mybatis学习：mybatis的注解开发CRUD操作

Dao层：

public interface IUserDao {

    /**
     * 查询所有结果
     * @return
     */
    @Select("select * from user")
    List<User> findAll();

    /**
     * 保存用户
     * @param user
     */
    @Insert("insert into user(username,address,sex,birthday) values(#{username},#{address},#{sex},#{birthday})")
    void saveUser(User user);

    /**
     * 更新用户
     * @param user
     */
    @Update("update user set username = #{username},address = #{address},sex = #{sex},birthday = #{birthday} where id = #{id}")
    void updateUser(User user);

    /**
     * 删除用户
     * @param id
     */
    @Delete("delete from user where id = #{id}")
    void deleteUser(Integer id);

    /**
     * 根据id查询用户
     * @param userId
     * @return
     */
    @Select("select * from user where id = #{id}")
    User findById(Integer userId);

    /**
     * 根据用户模糊查询
     * @param username
     * @return
     */
//    @Select("select * from user where username like #{username}")     //参数占位符
    @Select("select * from user where username like '%${value}%'")      //字符串拼接
    List<User> findUserByName(String username);

    /**
     * 查询总用户数量
     * @return
     */
    @Select("select count(*) from user")
    int findTotalUser();

}

test：

public class AnnotationCRUDTest {

    private InputStream in;
    private SqlSessionFactory factory;
    private SqlSession session;
    private IUserDao userDao;

    @Before
    public void init() throws IOException {
        in = Resources.getResourceAsStream("SqlMapConfig.xml");
        factory = new SqlSessionFactoryBuilder().build(in);
        session = factory.openSession();
        userDao = session.getMapper(IUserDao.class);
    }

    @After
    public  void  destory() throws IOException {
        session.commit();
        session.close();
        in.close();
    }

    @Test
    public  void testSave(){
        User user = new User();
        user.setUsername("flypig");
        user.setAddress("中国");

        userDao.saveUser(user);
    }

    @Test
    public void testUpdate(){
        User user = new User();
        user.setId(49);
        user.setUsername("flypighhh");
        user.setAddress("China");
        user.setSex("男");
        user.setBirthday(new Date());

        userDao.updateUser(user);
    }

    @Test
    public void testDelete(){
        userDao.deleteUser(49);
    }

    @Test
    public void testFindOne(){
        User user = userDao.findById(48);
        System.out.println(user);
    }

    @Test
    public void testFindUserByName(){
        //List<User> users = userDao.findUserByName("%王%");
        List<User> users = userDao.findUserByName("王");
        for (User user : users) {
            System.out.println(user);
        }
    }

    @Test
    public void testFindTotal(){
        int total = userDao.findTotalUser();
        System.out.println(total);
    }

}

 解决实体类属性和数据库表字段不对应：

@Results(id="userMap",value={
             @Result(id=true,column = "id",property = "userId"),
             @Result(column = "username",property = "userName"),
             @Result(column = "address",property = "userAddress"),
             @Result(column = "sex",property = "userSex"),
             @Result(column = "birthday",property = "userBirthday"),
})    

//其他可根据id调用
@ResultMap(value={"userMap"})
//@ResultMap("userMap")