Javax 约束：如果字段“类型”为 XXX，则应用 @NotNull 注释

Question

I have a Spring Boot app with Postgres that has the following entity:

 @Entity
 @Table(name = "message")
 public class Message {

  public enum MessageType {
    TEXT,
    LOCATION,
    IMAGE,
    REPLY,
    LIST,
    BUTTON
  }

  @Id
  @GeneratedValue(generator = "uuid")
  @GenericGenerator(name = "uuid", strategy = "uuid2")
  private String id;

  @Column(nullable = false)
  private MessageType type;

  private String text;

  @Embedded
  private LocationRequest location;

  @Embedded
  private ImageRequest image;

  @Embedded
  private ContextRequest reply;

What I need to do is apply some given constraints depending on the value of the MessageType. For Example, if type is equal to " LOCATION ", then I want to make sure all the fields of LocationRequest are required (ie not blank) Similarly, if instead the type is Image, I want that every field of ImageRequest is required.

Can this be achieved with Javax Constraints? If not, are there other ways to achieve it, perhaps using Hibernate?

Since my colleagues may add a record to the DB directly with an INSERT, I need those constraints to be generated for the table and not for my app (I'm using Hibernate schema autogeneration feature, ddl-auto=true ).

Answer 1

You can do that with check constraints, although it is a bit cumbersome. Something like this:

@Entity
@Table(name = "message")
@org.hibernate.annotations.Check("case type when 'LOCATION' then location_col1 is not null and locatoin_col2 is not null when 'IMAGE' then image_col1 is not null else true end")
public class Message {
...
}