I m trying to understand the core concepts of DDD and I m having some troubles dealing with validations.In fact, I m actually wondering where and when should I use specification pattern instead of Entity / ValueObject validations.Moreover, I m trying to find a way to avoid this kind of validation in my Application service :if(Email.isValid(emailString)){  User usr = new User(emailString);}In fact, what could happen if I have multiple validation like 10 - 20 on certain field ? I don't neither want to throw multiple exceptions, which are, in my sense, dedicated to critical errors.Any ideas ?
Specification pattern or entity / value object validation
java;domain driven design;validation;business rules