How to use application.properties values in javax.validation annotations

Question

I have a variable called notification.max-time-to-live in application.yaml file and want to use this as the value of javax.validation.constraints.@Max() annotation.

I've tried in many ways (using env.getProperty(), @Value, etc) and it says it must be a constant value, is there any way to do this?

No. Those annotations are processed by javax.validation not Spring. So no this isn't possible. You could write your own validator which reads this value and validates accordingly. — M. Deinum, Sep 27 '21 at 17:37
To voters: The answer to the question is no, but the question _as a question_ is reasonable to ask. — chrylis -cautiouslyoptimistic-, Sep 27 '21 at 17:40
Does this answer your question? [Javax Validation - Values from Properties](https://stackoverflow.com/questions/61768104/javax-validation-values-from-properties) — damndemon, Aug 11 '22 at 11:58

Ricardo Petronilho · Accepted Answer · 2021-09-28T10:28:22.257

I know this does not directly answer my question and as M. Deinum already said the answer is no. Nonetheless it's a simple workaround.

It's true that @Max and other javax annotations do not let us use dynamic values, however, we can create a custom annotation (as M. Deinum suggested) that uses values from application.yaml with spring @Value.

@Target({ElementType.FIELD})
@Retention(RetentionPolicy.RUNTIME)
@Documented
@Constraint(validatedBy = ValidTimeToLiveValidator.class)
public @interface ValidTimeToLive {

    String message() default "must be less than or equal to %s";

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

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

And the respective validator.

public class ValidTimeToLiveValidator implements ConstraintValidator<ValidTimeToLive, Integer> {

    @Value("${notification.max-time-to-live}")
    private int maxTimeToLive;

    @Override
    public boolean isValid(Integer value, ConstraintValidatorContext context) {
        // leave null-checking to @NotNull
        if (value == null) {
            return true;
        }
        formatMessage(context);
        return value <= maxTimeToLive;
    }

    private void formatMessage(ConstraintValidatorContext context) {
        String msg = context.getDefaultConstraintMessageTemplate();
        String formattedMsg = String.format(msg, this.maxTimeToLive);
        context.disableDefaultConstraintViolation();
        context.buildConstraintViolationWithTemplate(formattedMsg)
               .addConstraintViolation();
    }
}

Now we just need to add this custom annotation in the respective class.

public class Notification {

    private String id;
 
    @ValidTimeToLive
    private Integer timeToLive;

    // ...
}

How to use application.properties values in javax.validation annotations

1 Answers1