I have a field that it can have just two values, let us say "A" or "B". If we use FF4J (Fixed format 4J), so we can have a formatter and define an enum for that reason. How abount Apache Camel Bindy. I do not find anything similar to FF4J formatter.
No I don't think Bindy has that supported, but beanio and hence camel-beanio supports adding regex to a field. So you can use regex to restrict values. http://beanio.org/