Angular $http - spring - throws Exception but http status 200

Question

I got a behaviour I don't understand on an application using Spring and angular. An exception is Thrown in the http request. I did the test below.

@RequestMapping(value = "/contract/upload/excel", method = RequestMethod.POST)
public String uploadContractExcel(HttpServletRequest request, ModelMap model)   { 
if(true) {
throw new RuntimeException("my code is broken");
}
...

In JavaScript in the $http function instead of going into the error block, it returns to the success block with Status code 200 - OK. So I cannot handle any exception.

$http({
method : 'POST',
url : resolveAjax,
data : formData
}).then(
function successCallback(response) {
var data = response.data;
if (data.upload_error === "true") {
    $scope.busy = false;
    $scope.upload_error_message = data.upload_error_message;
} else {
    $scope.contractSummary = angular
            .fromJson(data.reference_excel_resolved);
    $scope.busy = false;
        $scope.tabindex = $scope.tabindex * 1 + 1;
    }
}, 
function errorCallback(response) {
    $scope.upload_error_message = 'Oups something went wrong';
});

Has anybody got an idea about what happens ? Thanks

Answer 1

If you want your client to receive a bad HTTP status like 400 etc, you should return such status in your controller. Throwing an exception will not suffice. You have a couple of options; don't throw the exception or create a @ControllerAdvice which handles exceptions for you.

PSEUDOCODE:

@RequestMapping(value = "/url", method = POST)
public ResponseEntity postYourObject(@RequestBody YourObject object) {
    if (true) {
        return new ResponseEntity<>("Something happened", HttpStatus.BAD_REQUEST);
    }
}

Or keep throwing your exception and create a controller advice like this.

@ControllerAdvice
public class GlobalControllerBehavior {

    @ExceptionHandler
    public ResponseEntity handleException(YourException e) {
        return new ResponseEntity<>(e.getMessage(), HttpStatus.BAD_REQUEST);
    }
}

Bottom line, if you don't return a HTTP status code like 4xx or 5xx your JavaScript error block will not be excecuted.