Spring 4: cannot get arguments annotations at interception?

I have this method:

@Override
public ClientDomain addClient(@Valid ClientDomain client) throws ValidationException {
    Client clientEntity = this.transformer.transform(client);
    Client clientEntityResponse = this.dao.save(clientEntity);
    return this.transformer.revert(clientEntityResponse);
}

To intercept it, i am using Spring 4 AOP. This is what i have:

import java.lang.annotation.Annotation;
import java.util.Set;

import javax.validation.ConstraintViolation;
import javax.validation.Validator;

import org.aopalliance.intercept.MethodInterceptor;
import org.aopalliance.intercept.MethodInvocation;
public class ValidationInterceptor
    implements MethodInterceptor {

    @Override
    public Object invoke(MethodInvocation invocation) throws Throwable {
        System.out.println("Validating " + invocation.getMethod().getName() + " method");

        Object[] asd = invocation.getArguments(); // Get object arguments
        invocation.proceed();
        return null;
    }

}

So, i want to get the arguments annotations, in this case, i would expect to recieve the @Valid annotation, and i couldn't find the way to do it. I've already tried this

    for (int i = 0; i < asd.length; i++) {
        System.out.println("Param: " + asd[i].toString());

        Annotation[][] annotations = invocation.getMethod().getParameterAnnotations();
        for (Annotation annotation : annotations[i]) {
            System.out.println("---" + annotation.getClass().getSimpleName());
        }
    }

But i am recieving an empty annotation object on getParametersAnnotations()

Do you know how i can do it ?