Java Bean Validation using Hibernate Validator - HowToDoInJava
Design by contract - Wikipedia
email validator not working on sign up · Issue #4108 · IQSS/dataverse · GitHub
Bean Validation specification
GitHub - OpenLiberty/guide-bean-validation: An introductory guide on how to use bean validation in Open Liberty to create a microservice to validate user input data: https://openliberty.io/guides/bean-validation.html