Spring boot 404 error custom error response ReST

I wanted to have the same error format (json) structure across all possible error scenarios, so I just registered my own ErrorController reusing the code from AbstractErrorController:

@Controller
@RequestMapping(path = "/error", produces = MediaType.APPLICATION_JSON_VALUE)
@ResponseBody
public class ErrorController extends AbstractErrorController {

public ErrorController(ErrorAttributes errorAttributes, ObjectProvider<ErrorViewResolver> errorViewResolvers) {
super(errorAttributes, errorViewResolvers.orderedStream().collect(Collectors.toUnmodifiableList()));
}

@RequestMapping
public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) {
final var status = getStatus(request);
if (status == HttpStatus.NO_CONTENT) {
return new ResponseEntity<>(status);
}
return new ResponseEntity<>(getErrorAttributes(request, ErrorAttributeOptions.defaults()), status);
}

@Override
public String getErrorPath() {
return null;
}
}

with this you dont need any controller advice, all errors go to error method by default

It is worked for me in case of @RestControllerAdvice with spring boot

spring.mvc.throw-exception-if-no-handler-found=true
server.error.whitelabel.enabled=false
spring.resources.add-mappings=false

@RestControllerAdvice
public class ErrorHandlerController {

@ExceptionHandler(NoHandlerFoundException.class)
@ResponseStatus(value = HttpStatus.NOT_FOUND )
public String handleNotFoundError(NoHandlerFoundException ex) {
return "path does not exists";
}
}

**Summing up all answers and comment, I think the best way to do this is-**

First, tell spring boot to throw exception in case of no handler found in ```application.properties```

spring.mvc.throw-exception-if-no-handler-found=true

Then handle ```NoHandlerFoundException``` in your application. I handle this by following way

@ControllerAdvice
public class GlobalExceptionHandler {
@ExceptionHandler(NoHandlerFoundException.class)
public void handleNotFoundError(HttpServletResponse response, NoHandlerFoundException ex) {
ErrorDto errorDto = Errors.URL_NOT_FOUND.getErrorDto();
logger.error("URL not found exception: " + ex.getRequestURL());
prepareErrorResponse(response, HttpStatus.NOT_FOUND, errorDto);
}
}

If you are using **Swagger** then you can view my [other answer][1] to exclude swagger URL from this exception handler


[1]:

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