Validating a Spring ResourceSupport-ed parent resource as a not empty property in a child resource - rest

Question

I'm looking for guidelines into validating a parent admin resource (AdminResource extending the Spring ResourceSupport class) as not being empty (#NotEmpty) in a child admin module resource (AdminModuleResource extending the Spring ResourceSupport class).
I understand the AdminResource class should also implement the Serializable interface ? Is that the way to go with Spring ResourceSupport-ed resources ?
Here are my resources:
public class AdminResource extends AbstractResource {
private String firstname;
private String lastname;
#NotEmpty
#Email
private String email;
private String password;
private String passwordSalt;
}
public class AdminModuleResource extends AbstractResource {
#NotEmpty
private String module;
#NotEmpty
private AdminResource adminResource;
}
public abstract class AbstractResource extends ResourceSupport {
#JsonProperty("id")
private Long resourceId;
public AbstractResource() {
}
public Long getResourceId() {
return resourceId;
}
public void setResourceId(Long resourceId) {
this.resourceId = resourceId;
}
}
As of now, the #NotEmpty validator annotation gives me the error: No validator could be found for type...
But adding the "implements Serializable" to the resources did not help and the exception remained when using the #NotEmpty validator annotation.
public abstract class AbstractResource extends ResourceSupport implements Serializable {
}
Of course, commenting out the #NotEmpty validator annotation makes the Maven build successful.
Thanks for any directions tips !
Kind Regards,
Stephane

Answer 1

#NotEmpty is only supported for CharSequences (String), Collections, Maps and arrays. It either checks whether the string or collection/array is empty. What does it even mean that a AdminResource is not empty. Do you mean #NotNull?
If it really would make semantically sense to have a #NotEmpty for AdminResource, you would have to implement a custom ConstraintValidator for it and registering it via XML (see also http://beanvalidation.org/1.1/spec/#xml-mapping-constraintdefinition).