Custom Validator(Hibernate)

Olá,
estou recebendo a seguinte mensagem de error ao tentar criar um Custom validator…

HTTP Status 500 - exception raised, check root cause for details: javax.validation.ValidationException: Unexpected exception during isValid call
type Exception report
message exception raised, check root cause for details: javax.validation.ValidationException: Unexpected exception during isValid call
description The server encountered an internal error that prevented it from fulfilling this request.
exception
br.com.caelum.vraptor.InterceptionException: exception raised, check root cause for details: javax.validation.ValidationException: Unexpected exception during isValid call
br.com.caelum.vraptor.interceptor.ExecuteMethodInterceptor.intercept(ExecuteMethodInterceptor.java:96)
br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:54)
br.com.caelum.vraptor.core.LazyInterceptorHandler.execute(LazyInterceptorHandler.java:61)
br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:54)
br.com.caelum.vraptor.interceptor.ParametersInstantiatorInterceptor.intercept(ParametersInstantiatorInterceptor.java:96)
br.com.caelum.vraptor.core.LazyInterceptorHandler.execute(LazyInterceptorHandler.java:59)
br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:54)
br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:56)
br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:54)
br.com.caelum.vraptor.interceptor.ExceptionHandlerInterceptor.intercept(ExceptionHandlerInterceptor.java:67)
br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:54)
br.com.caelum.vraptor.interceptor.FlashInterceptor.intercept(FlashInterceptor.java:83)
br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:54)
br.com.caelum.vraptor.interceptor.InstantiateInterceptor.intercept(InstantiateInterceptor.java:48)
br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:54)
br.com.caelum.vraptor.plugin.hibernate4.HibernateTransactionInterceptor.intercept(HibernateTransactionInterceptor.java:49)
br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:54)
br.com.caelum.vraptor.core.LazyInterceptorHandler.execute(LazyInterceptorHandler.java:61)
br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:54)
br.com.caelum.vraptor.interceptor.ResourceLookupInterceptor.intercept(ResourceLookupInterceptor.java:69)
br.com.caelum.vraptor.core.ToInstantiateInterceptorHandler.execute(ToInstantiateInterceptorHandler.java:54)
br.com.caelum.vraptor.core.DefaultInterceptorStack.next(DefaultInterceptorStack.java:54)
br.com.caelum.vraptor.core.EnhancedRequestExecution.execute(EnhancedRequestExecution.java:44)
br.com.caelum.vraptor.VRaptor$1.insideRequest(VRaptor.java:91)
br.com.caelum.vraptor.ioc.guice.GuiceProvider.provideForRequest(GuiceProvider.java:82)
br.com.caelum.vraptor.VRaptor.doFilter(VRaptor.java:88)

Minhas classes sao as seguintes:

[code]import static java.lang.annotation.ElementType.ANNOTATION_TYPE;
import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.Target;
import javax.validation.Constraint;
import javax.validation.Payload;

@Target({FIELD, TYPE, ANNOTATION_TYPE})
@Retention(RUNTIME)
@Constraint(validatedBy = ConfirmValidator.class)
@Documented

public @interface Confirm {
String message() default "Teste Validação";
Class<?>[] groups() default {};
Class<? extends Payload>[] payload() default {};
} [/code]

import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;
public final class ConfirmValidator implements
		ConstraintValidator&lt;Confirm, String&gt; {

	
	public void initialize(Confirm constraintAnnotation) {
		
	}
	public boolean isValid(String value, ConstraintValidatorContext context) {
		context.disableDefaultConstraintViolation();
		boolean isValid;
		
		if(value.toString().isEmpty()){
			//context.buildConstraintViolationWithTemplate(message).addConstraintViolation();
			
			isValid = false;
		}else{
			isValid = true;
		}
		return isValid;
		
	}
}

E a outra classe seria a bean…

com a annotation

@Confirm(message="Faltando a descrição")
@Column(nullable=false, length=50)
private String descricao;

Alguém sabe qual seria a causa do erro?

desde já agradeço! :wink: