Support javax.validation annotation with Validator for Repository Entity [DATAJDBC-482]

[spring-projects-issues]

MyeongHyeonLee opened DATAJDBC-482 and commented

When an Entity is saved to a Repository, it would be nice to have a javax.validation annotation with the Validator. (like JPA BeanValidationEventListener)

https://github.com/hibernate/hibernate-orm/blob/master/hibernate-core/src/main/java/org/hibernate/cfg/beanvalidation/BeanValidationEventListener.java#L103

 

 

@Table
public class Person {
   @Id
   private Long id;
   
   @Size(min = 1, max = 100)
   private String name;

   @PositiveOrZero
   private int age;
}

 

I have implemented Validation with EntityCallback.

However, it would be nice to apply it as a basic  feature in Spring Data JDBC.

Please review the appropriateness of this proposal.

 

 

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Affects: 2.0 M2 (Neumann)

[spring-projects-issues]

Jens Schauder commented

Why should validation be tied to persistence?

Shouldn't validation happen at the very beginning of any processing of input while persisting changes happens pretty much at the end?

 

[spring-projects-issues]

MyeongHyeonLee commented

In complex business processes, input data and persistent data can be different.

AggregateRoot is responsible for the invarient of Aggregate.

https://docs.microsoft.com/en-us/dotnet/architecture/microservices/microservice-ddd-cqrs-patterns/infrastructure-persistence-layer-design#define-one-repository-per-aggregate

 

I think Aggregate should check the invarient of the final state before it is persisted.

In Spring Data there are features to change entity state inside repository.

(EntityCallback, AuditAware ...)

 

I think the Repository needs validation of the change state on the EntityCallback before giving it persistence.

 

 

[spring-projects-issues]

Jens Schauder commented

I think Aggregate should check the invarient of the final state before it is persisted.

Exactly. But this issue asks to move it into the repository where it doesn't belong in my opinion

[spring-projects-issues]

MyeongHyeonLee commented

Changed the Component in this issue to Repository.

Does it match your request? Or was it another intension?

[spring-projects-issues]

Jens Schauder commented

No my comment wasn't about the component field of Jira it was about where to put validation logic in an application.

There is a very valid use case to put it on the boundary of the system. For example when data enters the system you probably want to validate it. This might be done through bean validation (Spring MVC has support for it https://spring.io/guides/gs/validating-form-input/) or as part of the implementation of an aggregate root as you stated yourself.

But I don't think validating an object when persisting it in the database makes any sense in a well structured application.
If it doesn't match the constraints encoded in the database this is a bug and not a case for validation.
If it is invalid according to your business rules it shouldn't have been created in the first place.

[spring-projects-issues]

MyeongHyeonLee commented

Jens Schauder

Thanks for the feedback.

I will perform validation where I need it.

I will close this issue.

Thank you