FEATURE: Add Java Bean Validation Annotations

[Adam1302]

What? https://www.baeldung.com/java-validation

Why? Reducing code, preventing errors in input

How?

• Add @ NotNull(message = “…”) annotations to DTO fields to ensure some fields (ex. title) always exist
  • @ NotEmpty as well for Strings
  • Find some equivalents for numbers maybe
• Add @ Size(min = x, max = y, message = “[whatever field] cannot be more than y characters long)
  • Ex. Positive word count, years published can’t be in the future (use Date.year to ensure it’s reusable), etc.
• This ticket will also involve the creation of an Exception Handler within the @ControllerAdvice class
  • See O’Reilly video “Custom Handlers for Field Level Error” (reach out to lead dev for more details)
• Then, activate these checks by marking each Controller function parameter that is a DTO with “@ Valid”. This triggers the checks on the DTO object.
• Make sure this ticket comes AFTER the Exception Epic/Story
• Add these to the Login ticket, too
• Do this BEFORE the login ticket