原始dao的开发与动态代理开发

1、原始dao的开发

1.1 创建映射文件

1.2 新建Dao接口

public interface UserDao {
	
	/**根据用户ID查询用户信息
	 */
	User getUserById(Integer id);
	
	/**
	 * 根据用户名查找用户列表
	 */
	List<User> getUserByUserName(String name);
	
	/**
	 * 添加用户
	 */
	void insertUser(User user);
}

1.3新建接口实现类

public class UserDaoImpl implements UserDao {

	@Override
	public User getUserById(Integer id) {
		SqlSession sqlSession = SqlSessionFactoryUtils.getSqlSessionFactory().openSession();
		User user = sqlSession.selectOne("user.getUserById", id);
		sqlSession.close();
		return user;
	}

	@Override
	public List<User> getUserByUserName(String name) {
		SqlSession sqlSession = SqlSessionFactoryUtils.getSqlSessionFactory().openSession();
		List<User> list = sqlSession.selectList("user.getUserByName", name);
		sqlSession.close();
		return list;
	}

	@Override
	public void insertUser(User user) {
		SqlSession sqlSession = SqlSessionFactoryUtils.getSqlSessionFactory().openSession();
		sqlSession.insert("user.insertUser", user);
		sqlSession.commit();
		sqlSession.close();
	}

}

1.4 使用dao进行测试

public class UserDaoTest {

	@Test
	public void testGetUserById() {
		UserDao userDao = new UserDaoImpl();
		User user = userDao.getUserById(30);
		System.out.println(user);
	}

	@Test
	public void testGetUserByUserName() {
		UserDao userDao = new UserDaoImpl();
		List<User> list = userDao.getUserByUserName("张");
		for (User user : list) {
			System.out.println(user);
		}
	}

	@Test
	public void testInsertUser() {
		UserDao userDao = new UserDaoImpl();
		User user = new User();
		user.setUsername("张飞3");
		user.setAddress("深圳市黑马");
		user.setBirthday(new Date());
		user.setSex("1");
		userDao.insertUser(user);
	}

}

2 动态代理dao开发规则

2.1 动态代理dao开发规则

1. namespace必需是接口的全路径名
2. 接口的方法名必需与映射文件的sql id一致
3. 接口的输入参数必需与映射文件的parameterType类型一致
4. 接口的返回类型必须与映射文件的resultType类型一致

2.2 开发步骤

2.2.1 创建映射文件

2.2.2 创建接口，注意开发规则

2.2.3 在核心配置文件中加载映射文件

2.2.4 测试动态代理Dao

public class UserMapperTest {

	@Test
	public void testGetUserById() {
		// 加载配置得到SqlSession
		SqlSession sqlSession = SqlSessionFactoryUtils.getSqlSessionFactory().openSession();
		// 获取代理对象
		UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
		// 查询数据
		User user = userMapper.getUserById(30);
		System.out.println(user);
		// 关闭资源
		sqlSession.close();
	}

	@Test
	public void testGetUserByUserName() {
		SqlSession sqlSession = SqlSessionFactoryUtils.getSqlSessionFactory().openSession();
		// 获取代理对象
		UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
		// 查询数据
		List<User> list = userMapper.getUserByName("张");
		for (User user : list) {
			System.out.println(user);
		}
		// 关闭资源
		sqlSession.close();
	}

	@Test
	public void testInsertUser() {
		SqlSession sqlSession = SqlSessionFactoryUtils.getSqlSessionFactory().openSession();
		UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
		User user = new User();
		user.setUsername("张飞飞");
		user.setAddress("上海市");
		user.setBirthday(new Date());
		user.setSex("1");
		userMapper.insertUser(user);
		// 提交事务
		sqlSession.commit();
		// 关闭资源
		sqlSession.close();
	}
}