SpringBoot JPA接口的save（）和delete（）不适用于ArrayList或Long

Question

我正在关注使用SpringBoot 1.3的教程。我正在使用SpringBoot 2.0的最新版本。我正在创建REST API。我需要帮助使1.3代码适应2.0规范，save()并且delete()现在期望对象超过long ids。我该如何重写接受接口long id' and 'ArrayList？

现在的代码如下：

基础对象

@Entity
public class HotelBooking {

@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE)
private long id; // could be Long

private String hotelName;
private double pricePerNight;
private int nbOfNights;

public HotelBooking(){} 

public HotelBooking(String hotelName, double pricePerNight, int nbOfNights) {
    this.hotelName = hotelName;
    this.pricePerNight = pricePerNight;
    this.nbOfNights = nbOfNights;
}
// getters omitted
}

介面

@Repository
public interface BookingRepository extends JpaRepository<HotelBooking, Long> {
data/jpa/docs/2.1.0.M1/reference/html/
    List<HotelBooking> findByPricePerNightLessThan(double price);
}

使用a long id删除database

@RequestMapping(value = "/delete/id")
public List<HotelBooking> remove(@PathVariable long id) {
    bookingRepository.delete(id);
    return bookingRepository.findAll();
}

尝试将ArrayList对象保存到 database

 @Override
    public void run(String... strings) throws Exception {

        List<HotelBooking> bookings = new ArrayList<>();

        bookings.add(new HotelBooking("Marrior", 200.50, 3));
        bookings.add(new HotelBooking("Ibis", 90, 4));
        bookings.add(new HotelBooking("Novotel", 140.74, 1));

        bookingRepository.save(bookings);
    }

问题

以上内容在SpringBoot 2.0中不再起作用。尝试通过ID删除时，我收到一条错误消息- Error:(61, 34) java: incompatible types: long cannot be converted to romaniancoder.booking.HotelBooking 现在期望使用对象而不是long id数据库中的对象。

当试图保存一个ArrayList我得到这个错误 - Error:(40, 26) java: method save in interface org.springframework.data.repository.CrudRepository<T,ID> cannot be applied to given types; required: S found: java.util.List<romaniancoder.booking.HotelBooking> reason: inferred type does not conform to upper bound(s) inferred: java.util.List<romaniancoder.booking.HotelBooking> upper bound(s): romaniancoder.booking.HotelBooking 这是因为如果它需要一个类扩展或什么工作？我不确定...

阅读Spring Docs之后，我不明白为什么会更改，以及如何编写代码以接受并long id在中找到内容database。我不明白如何适应save()接受ArrayLists。

Answer 1

您可以使用repository.deleteById(Long)和repository.saveAll(ArrayList)。这些方法在SpringBoot 2.0中引入。