GWT JSR303 Validation, validate method OR use custom annotations

Question

I'm trying to use GWT's 2.5 in-build validation feature. I have a few complex validations. Cross field validation with Hibernate Validator (JSR 303) suggests that I could either include methods which do the validation OR write my own annotations. However, both don't work.

public class PageData extends Serializable
    @NotNull(message="Cannot be null!")
    Boolean value

    @AssertTrue(message="isValid() is false!")
    private boolean isValid() {
        return false;
    }

    //Getters and Setters
}

Boolean value is validated. However, isValid() is never called/validated. But why? Is this a GWt specific problem?

Then I tried to write my own annotation, The @FieldMatch example in Cross field validation with Hibernate Validator (JSR 303) uses Beans.getProperty() from Apache Commons BeanUtils, which I cannot use in GWT. Is there any way to make these kind of complex annotations work in GWT?

Answer 1

Here is how I created a custom validation that works across multiple fields of one bean. It checks that when the field ContactProfile for a Contact bean is set to COMPANY, then company name must be filled out, otherwise when set to PERSON, the first name or last name must be filled out :

Annotation definition :

@Target({ ElementType.TYPE })
@Retention(RetentionPolicy.RUNTIME)
@Constraint(validatedBy = ValidCompanyOrPersonValidator.class)
public @interface ValidCompanyOrPerson {

    String message() default "{contact.validcompanyorperson}";

    Class<?>[] groups() default {};

    Class<? extends Contact>[] payload() default {};
}

Implementation :

public class ValidCompanyOrPersonValidator implements ConstraintValidator<ValidCompanyOrPerson, Contact> {

    ValidCompanyOrPerson annotation;

    public void initialize(ValidCompanyOrPerson annotation) {
        this.annotation = annotation;
    }

    @SuppressWarnings("nls")
    public boolean isValid(Contact contact, ConstraintValidatorContext context) {
        boolean ret = false;
        if (contact.getContactProfile() == null) {
        } else if (contact.getContactProfile().equals(ContactProfile.COMPANY)) {
            ret = (contact.getCompanyName() != null);
        } else if (contact.getContactProfile().equals(ContactProfile.PERSON)) {
            ret = (contact.getGivenName() != null || contact.getFamilyName() != null);
        }
        return ret;
    }
}

Now I can set

@ValidCompanyOrPerson
public class Contact  {
 ...
}

I can use this validation both client (GWT) and server side.

Hope that helps ....