Mybatis 控制层常用方法例子

以下是 Mybatis 控制层常用方法的示例：

1. 查询单个对象

public User getUserById(int id) {
    try(SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession()) {
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        return userMapper.getUserById(id);
    }
}

2. 查询多个对象

public List<User> getAllUsers() {
    try(SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession()) {
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        return userMapper.getAllUsers();
    }
}

3. 插入单个对象

public void addUser(User user) {
    try(SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession()) {
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        userMapper.addUser(user);
        sqlSession.commit();
    }
}

4. 更新单个对象

public void updateUser(User user) {
    try(SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession()) {
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        userMapper.updateUser(user);
        sqlSession.commit();
    }
}

5. 删除单个对象

public void deleteUser(int id) {
    try(SqlSession sqlSession = MyBatisUtil.getSqlSessionFactory().openSession()) {
        UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
        userMapper.deleteUser(id);
        sqlSession.commit();
    }
}

其中，`UserMapper` 是 Mybatis 的 Mapper 接口，具体实现可以参考 Mybatis 的官方文档。`MyBatisUtil` 是一个用于获取 SqlSessionFactory 的工具类，具体实现可以参考以下代码：

public class MyBatisUtil {
    private static SqlSessionFactory sqlSessionFactory;

    static {
        try {
            Reader reader = Resources.getResourceAsReader("mybatis-config.xml");
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);
        } catch (IOException e) {
            throw new RuntimeException(e.getMessage());
        }
    }

    public static SqlSessionFactory getSqlSessionFactory() {
        return sqlSessionFactory;
    }
}

其中，`mybatis-config.xml` 是 Mybatis 的配置文件，具体内容可以参考 Mybatis 的官方文档。