Mastering data validation in Java and Spring. Part 4: Learn how to test validation logic, return structured API error responses, and organize validation code in Spring Boot projects. Covers Bean Validation, custom constraints, and the three layers of validation: Boundary, Domain, and Persistence.
Mastering data validation in Java and Spring. Part 3: Learn the difference between @Valid and @Validated, and how to write custom constraints for domain-specific rules like Swedish personal numbers.
Mastering data validation in Java and Spring. Part 2: How to separate boundary validation, domain invariants, and persistence rules to create maintainable architecture.
Mastering data validation in Java and Spring. Part 1: How to stop scattered null checks and defensive plumbing from complicating your business logic.
Stop using magic numbers in Java. Learn how to improve delimited file parsing readability and maintainability using Enum field mapping. Refactoring guide.