java - Hibernate 真的需要无参数构造函数吗？

Question

众所周知，Hibernate 需要无参数构造函数，但我试图删除它，令人惊讶的是一切正常。我在我的项目中使用 Spring-Boot，当我运行程序时，我收到了这条消息：

2020-09-04 00:13:24.749  INFO 12825 --- [         task-1] org.hibernate.tuple.PojoInstantiator     : HHH000182: No default (no-argument) constructor for class: com.jb.couponSystem.data.entity.Coupon (class must be instantiated by Interceptor)

实例化我的类的拦截器是什么？如果我没有 args 构造函数，为什么在其他项目中 Hibernate 会抛出异常（如预期的那样）？

这是课程，我使用 Lombok @Data 来减少样板代码：

@Entity
@Data
public class Coupon {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
@Setter(AccessLevel.NONE)
private long id;
@Setter(AccessLevel.NONE)
@Column(nullable = false)
private  String title;
@Setter(AccessLevel.NONE)
@Column(nullable = false)
private LocalDate startDate;
@Setter(AccessLevel.NONE)
@Column(nullable = false)
private LocalDate endDate;
@Setter(AccessLevel.NONE)
@Column(nullable = false)
private Category category;
private int amount;
@Setter(AccessLevel.NONE)
@Column(nullable = false)
private String description;
@Setter(AccessLevel.NONE)
@Column(nullable = false)
private double price;
@Setter(AccessLevel.NONE)
private String imageURL;
@ManyToOne
@JoinColumn(name = "company_id")
@JsonProperty(access = JsonProperty.Access.WRITE_ONLY)
private Company company;
@JsonProperty(access = JsonProperty.Access.WRITE_ONLY)
@ManyToMany
@JoinTable(name = "customer_coupon",
        joinColumns = @JoinColumn(name = "coupon_id"),
        inverseJoinColumns = @JoinColumn(name = "customer_id"),
        uniqueConstraints = @UniqueConstraint(columnNames
                = {"customer_id", "coupon_id"}))
private List<Customer> customers;


public Coupon(String title, LocalDate startDate, LocalDate endDate,
              Category category, int amount, String description, double price, String imageURL) {
    this.title = title;
    this.startDate = startDate;
    this.endDate = endDate;
    this.category = category;
    this.amount = amount;
    this.description = description;
    this.price = price;
    this.imageURL = imageURL;
}


public boolean isOutOfStock() {
    return amount <= 0;
}

}

更新：为了清楚起见，这种行为肯定与 lombok @Data 无关。即使我删除了该注释并添加了 getter 和 setter，它仍然可以使用相同的 Hibernate 消息。

这是关于这个问题的一些有趣的答案，但它假设你必须自己实现拦截器——我没有做。也许 Spring-Boot 本身在创建会话工厂时传递了一个已经实现的拦截器？

标签： javaspring-boothibernate