05.SpringBoot 集成

Spring Boot 中集成 MyBatis

多类型支持

Optional

在 Mybatis 3.5 支持 Optional 之后，我们还可以将判断优雅化为如下形式：

@Mapper
public interface UserMapper {
  @Select("select * from user where id = #{id}")
  Optional<User> selectById(Long id);
}

public class UserController {
  @Autowired
  private UserMapper userMapper;

  @GetMapping("/{id}")
  public User findById(@PathVariable Long id) {
    User user = this.userMapper.selectById(id);
    if (user == null) {
      // 抛异常，或者做点其他事情
    }
  }
}

public class UserController {
  @Autowired
  private UserMapper userMapper;

  @GetMapping("/{id}")
  public User findById(@PathVariable Long id) {
    return this.userMapper.selectById(id)
      .orElseThrow(
        () -> new IllegalArgumentException("This user does not exit!")
      );
  }
}

最近更新于 0001-01-01