How to use MethodValidationPostProcessor when having multiple (custom) validators?

Question

In one of my Spring applications, I am planning to use MethodValidationPostProcessor for validating service method parameters. As I know, for this, I'll have to have a MethodValidationPostProcessor object in the ApplicationContext, which in turn will have to have one validator injected. I am doing it like this in a @Configuration class:

@Bean
public LocalValidatorFactoryBean validator() {
    return new LocalValidatorFactoryBean();
}

@Bean
public MethodValidationPostProcessor getMethodValidationPostProcessor(){
    MethodValidationPostProcessor processor = new MethodValidationPostProcessor();
    processor.setValidator(validator());
    return processor;
}

And then, my service classes look like this:

@Service
@Validated
public class SomeService {

    public void someMethod(@Valid SomeForm someForm) {
        .
        .
        .
    }

}

But, a few of my objects would be needing some custom validators. For example, for the signup form, I plan to use a JoinDataValidator extending the LocalValidatorFactoryBean, like this:

@Service("joinDataValidator")
public class JoinDataValidator extends LocalValidatorFactoryBean {

    @Override
    public void validate(final Object target, final Errors errors) {
      super.validate(target, errors);
      // check for duplicate email
    }

    @Override
    public boolean supports(Class<?> clazz) {
      return JoinForm.class.equals(clazz);
    }

}

So, I'll be needing multiple validators, for different service classes. I could not figure out how to tell the configured MethodValidationPostProcessor to use different validators depending on the Service class being validated, or what could be a good way to handle this kind of scenario. I would appreciate help.

Update: Have created a ticket: https://jira.spring.io/browse/SPR-12563