problem-details-rfc9457

# Problem Details — RFC 9457 Spring Boot 4.x includes native RFC 9457 support via `ProblemDetail` on Spring Framework 7. ## Enable in application.yml ```yaml spring: mvc: problemdetails: enabled: true # enables Spring's built-in RFC 9457 handler ``` ## ProblemDetail Response Shape ```json { "type": "https://api.example.com/errors/order-not-found", "title": "Order Not Found", "status": 404, "detail": "No order found with id: 550e8400-e29b-41d4-a716-446655440000", "instance": "/api/v1/orders/550e8400-e29b-41d4-a716-446655440000", "errorCode": "ORDER_NOT_FOUND", "timestamp": "2026-04-13T10:00:00Z" } ``` ## Global Exception Handler ```java @RestControllerAdvice public class GlobalExceptionHandler extends ResponseEntityExceptionHandler { @ExceptionHandler(EntityNotFoundException.class) public ProblemDetail handleNotFound(EntityNotFoundException ex, HttpServletRequest request) { ProblemDetail problem = ProblemDetail.forStatusAndDetail(HttpStatus.NOT_FOUND, ex.getMessage()); problem.setType(URI.create("https://api.example.com/errors/not-found")); problem.setTitle("Resource Not Found"); problem.setInstance(URI.create(request.getRequestURI())); problem.setProperty("errorCode", "NOT_FOUND"); problem.setProperty("timestamp", Instant.now()); return problem; } @ExceptionHandler(BusinessRuleViolationException.class) public ProblemDetail handleBusinessRule(BusinessRuleViolationExc...