Alternatives with higher priority are not working on converters

[Turini]

as reported here https://groups.google.com/forum/#!topic/caelum-vraptor/6SoCRx2tEBM

VRaptor/CDI still run CalendarConverter instead of CustomCalendarConverter:

@Alternative 
@Priority(Interceptor.Priority.APPLICATION)
@Convert(Calendar.class)
public class CustomCalendarConverter implements Converter<Calendar>{

    @Override
    public Calendar convert(String value, Class<? extends Calendar> type) {
        return null; // anything;
    }
}

[nykolaslima]

This should be happening because DefaultConverters is registering all Converters implementations that CDI founds.
Using @Alternative we do not "remove" the old implementation, so the both CalendarConverter and CustomCalendarConverter are registered.
Using @Specializes we tell to CDI to "remove" other implementations and only consider this implementation CustomCalendarConverter. This way DefaultConverters only register the CustomCalendarConverter.

When we are registering the converter, we may need to check if there is another converter for the same class and if there is, we need to ask CDI whom we should use.