How to apply #ControllerAdvice from a non-controller? - spring-boot

Question

Is there a way in which we can generate the JSON response from within the code that an API endpoint would show when a controller is called.
I basically want the application to call one of its own controllers and generate the response as a JSON string but not by making an HTTP call.
Calling the controller method and applying an objectmapper on it gives back the results just fine, but when there are exceptions it throws it through. However, I want it to generate the error response that would have generated from #ControllerAdvice exception handlers.
Is it possible to apply the exception handlers defined in #ControllerAdvice to an exception caught in a variable from within the application (Not by making an HTTP call)?
I am building a bulk api so that instead of the user calling an api multiple times, they can just put a list of payloads to this new bulk api, and internally I want to save the responses of each subrequest within the bulk api's db entity itself, and for that I need the exact json responses for each subrequest as if the original api was called.
I can do an exception handling separately for this bulk api code but then that would duplicate the code I already have in my controller advice.
One solution I have come up with is given below. However, if I use it I'll have to remove all my current exception handlers and just use one single exception handler accepting Exception.
Controller Advice:
#ExceptionHandler(ConversionFailedException.class)
public ResponseEntity<ErrorResponse> handleConversionFailedException(final ConversionFailedException e) {
return buildResponseEntity(HttpStatus.BAD_REQUEST, e);
}
#ExceptionHandler(value = {ActionNotFoundException.class})
public ResponseEntity<ErrorResponse> handleActionNotFoundException(ActionNotFoundException e) {
return buildResponseEntity(HttpStatus.NOT_FOUND, e);
}
// someone just added it
#ExceptionHandler(value = {NewRuntimeException.class})
public ResponseEntity<ErrorResponse> handleNewRuntimeException(NewRuntimeException e) {
return buildResponseEntity(HttpStatus.INTERNAL_SERVER_ERROR, e);
}
Bulk API code:
try {
}catch(ConversionFailedException e){
return buildResponseEntity(HttpStatus.BAD_REQUEST, e);
}catch(ActionNotFoundException e){
return buildResponseEntity(HttpStatus.NOT_FOUND, e);
}
// they forgot to add it here
My current solution:
Controller Advice:
#ExceptionHandler(Exception.class)
public ResponseEntity<String> handleAllExceptions(final Exception e) {
return ExceptionHandlerUtil.funcA(e);
}
ExceptionHandlerUtil class (New):
private ResponseEntity<ErrorResponse> funcA(Exception e) {
if (e instanceof ConversionFailedException) {
return buildResponseEntity(HttpStatus.BAD_REQUEST, e);
}
else if (e instanceof ActionNotFoundException) {
return buildResponseEntity(HttpStatus.NOT_FOUND, e);
}
// they can add any new exception here, and both the parts of the code will be able to handle it
}
Bulk API code:
try {
}catch(Exception e){
return ExceptionHandlerUtil.funcA(e);
}