: Combines @Controller and @ResponseBody , signaling that the class handles web requests and returns data (like JSON) directly.
: Maps the incoming HTTP request body directly to a Java object, automatically handling deserialization (usually from JSON) via libraries like Jackson . Spring REST
: Implement a global exception handler (using @ControllerAdvice ) to return consistent error responses when a POST fails. Consuming POST Services : Combines @Controller and @ResponseBody , signaling that