In Spring MVC, a controller method can return various types of values, each serving different purposes depending on the specific needs of the application. Here are some of the valid return types that a Spring MVC controller method can use:
String: When a controller method returns a String, it typically represents the name of the view to be rendered. The view name is then resolved by the view resolver, and the corresponding view (like a JSP or a Thymeleaf template) is rendered to the user[1].
ModelAndView: This is a container object that includes both the model data and the view name. It allows a controller to return both the data and the view in one return value. This is useful when you need to send data to the view along with the view name[1][2].
HttpEntity or ResponseEntity: These are used to return full HTTP responses, including the status code, headers, and body. ResponseEntity is a subclass of HttpEntity with additional methods to manipulate HTTP headers and status codes, making it useful for RESTful web services[1][2].
HttpHeaders: This return type allows the method to return only HTTP headers, without a body[1].
void: If a controller method returns void, it means that the method handles the response itself (through response.getWriter() or similar), and Spring MVC does not need to do anything further with the response[1].
@ResponseBody: When a method is annotated with @ResponseBody, the return type can be any object. Spring will automatically serialize this object to JSON or...
