RangeValidator Question (there in 3.1.0.GA, not 4.0.2.GA)

bootlaces · **Joined:** Fri Apr 09, 2010 3:55 pm **Posts:** 8

Hi,

We are using Hibernate Validator to augment the UI code that constructs a form (using Vaadin as the UI framework). We are scanning our beans looking for validation annotations, then marking the field (constructed by Vaadin) with a special "do validation this way" method.

we have something like this:

Code:

annotation = attribute.getAnnotation(Range.class);
if (annotation != null) {
    final Range rangeAnnotation = (Range)annotation;
    field.addValidator(new RangeValidator(getI18nValidationMessage(rangeAnnotation.message()), rangeAnnotation));
}

Then, in our RangeValidator, we have something that *should* be like this:

Code:

public RangeValidator(final String message, final Range rangeAnnotation) {
    super(message);
    rangeValidator = new org.hibernate.validator.constraints.impl.RangeValidator();
    rangeValidator.initialize(rangeAnnotation);
}

I say *should* because org.hibernate.validator.constraints.impl.RangeValidator does not exist, whereas another class that we *are* using, org.hibernate.validator.constraints.impl.EmailValidator does exist.

All this is okay (sort of :-)), I can easy write my own RangeValidator like the Reference documentation says, but I have a few questions:

1. Should org.hibernate.validator.constraints.impl.RangeValidator not be there? (it's in Validator 3.1.0.GA)
2. If it has been removed, what replaces it? Would @Size offer the equivalent functionality?

Thank you.

-=bootlaces=-

bootlaces · **Joined:** Fri Apr 09, 2010 3:55 pm **Posts:** 8

Hi,

For those interested (and whilst I'm still waiting an answer :-), this may be of help:

Code:

@SuppressWarnings("serial")
public class RangeValidator extends AbstractStringValidator {

    private final MinValidatorForString minValidator;
    private final MaxValidatorForString maxValidator;

    public RangeValidator(final String message, final Range rangeAnnotation) {
        super(message);

        minValidator = new MinValidatorForString();
        maxValidator = new MaxValidatorForString();

        final ClassLoader classLoader = getClass().getClassLoader();

        final Min min = (Min)Proxy.newProxyInstance(classLoader, new Class<?>[]{Min.class}, new InvocationHandler() {

            public Object invoke(final Object proxy, final Method method, final Object[] args) throws Throwable {
                return rangeAnnotation.min();
            }
        });

        final Max max = (Max)Proxy.newProxyInstance(classLoader, new Class<?>[]{Max.class}, new InvocationHandler() {

            public Object invoke(final Object proxy, final Method method, final Object[] args) throws Throwable {
                return rangeAnnotation.max();
            }
        });

        minValidator.initialize(min);
        maxValidator.initialize(max);

    }

    @Override
    protected boolean isValidString(final String value) {
        return minValidator.isValid(value, null) && maxValidator.isValid(value, null);
    }
}

AbstractStringValidator is a Vaadin class, the system calls isValidString.

-=bootlaces=-

Gunnar · **Joined:** Sat Jan 24, 2009 12:46 pm **Posts:** 388

As of Hibernate Validator 4 @Range is realized as so-called composed constrained (based on @Min and @Max), therefore there is no need for a dedicated validator anymore. Btw. I would suggest to work with @Size, as it is the standard annotation from the JSR 303 API.

I don't know Vaadin, but your approach for integrating Bean Validation/Hibernate Validator seems a bit unusual to me. Did you take a look at javax.validation.Validator#validateValue() already? This method checks, whether a given value would be valid for a given attribute of a class, without the need to actually write this value into the model. This allows for a more generic integration of the BV API, and also is the approach followed by JSF 2.

Gunnar

bootlaces · **Joined:** Fri Apr 09, 2010 3:55 pm **Posts:** 8

Hi Gunnar,

Thank you for your helpful reply :-)

-=bootlaces=-