While implementing a global exception handler in Spring, I noticed that in case of a not recognized Accept header, Spring would throw it's own internal error. What I need is to return a custom JSON error structure instead. Works fine for application specific exceptions and totally fails for Spring HttpMediaTypeNotAcceptableException.
This code tells me "Failed to invoke #ExceptionHandler method: public java.util.Map RestExceptionHandler.springMalformedAcceptHeaderException()" when I try to request a page with incorrect Accept header. Any other way to return custom JSON for spring internal exceptions?
#ControllerAdvice
public class RestExceptionHandler {
#ExceptionHandler(value = HttpMediaTypeNotAcceptableException.class)
#ResponseBody
public Map<String, String> springMalformedAcceptHeaderException() {
Map<String, String> test = new HashMap<String, String>();
test.put("test", "test");
return test;
}
}
Eventually figured that the only way is to do the json mapping manually.
#ExceptionHandler(value = HttpMediaTypeNotAcceptableException.class)
#ResponseBody
public String springMalformedAcceptHeaderException(HttpServletResponse response) {
// populate errorObj, set response headers, etc
ObjectWriter jsonWriter = new ObjectMapper().writer();
try {
return jsonWriter.writeValueAsString(errorObj);
} catch(Exception e){}
return "Whatever";
}
Related
I'm working on a spring-boot application. I tried handling exceptions .But i guess there is something wrong about how I'm doing it because it always throws internal server error 500.
I tried setting up custom exception classes and also used response status codes with #ResponseStatus. But regardless of what the exception is it throws an internal server error only.
I'm using intellij and the message i've given in the exception is printed there but the response body is empty.This i guess must be because it is throwing an internal server error.
Controller class
#RequestMapping(value = "/attendance",method = RequestMethod.POST)
public ResponseEntity<?> enterAttendance(#RequestBody ViewDTO viewDTO) throws CustomException{
return new ResponseEntity<>(tempResultServices.handleAttendance(viewDTO),HttpStatus.OK);
}
}
Service layer
#Override
public TempResult handleAttendance(ViewDTO viewDTO) throws CustomException {
TempIdentity tempIdentity=new TempIdentity();
tempIdentity.setRegistrationNo(viewDTO.getRegistrationNo());
tempIdentity.setCourseId(viewDTO.getCourseId());
tempIdentity.setYear(viewDTO.getYear());
tempIdentity.setSemester(viewDTO.getSemester());
User user=userService.findByUserId(viewDTO.getUserId());
tempIdentity.setUser(user);
if(!viewDTO.isAttendance()){
TempResult tempResultUser =new TempResult(tempIdentity,viewDTO.isAttendance(),0);
ResultIdentity resultIdentity=new ResultIdentity(tempIdentity.getRegistrationNo(),tempIdentity.getCourseId(),tempIdentity.getYear(),tempIdentity.getSemester());
Result result=new Result(resultIdentity,0,"E*");
AttendanceDraft attendanceDraft=atteDraftService.findDraft(viewDTO.getRegistrationNo(),viewDTO.getCourseId(),viewDTO.getYear(),viewDTO.getSemester(),viewDTO.getUserId());
if(attendanceDraft!=null){
attendanceDraft.setStatus(true);
atteDraftService.save(attendanceDraft);
//atteDraftService.delete(attendanceDraft);
tempResultRepository.save(tempResultUser);
resultRepository.save(result);
return tempResultUser;
}
else{
throw new CustomException("No draft available");
}
}
else{
TempResult tempResultUser =new TempResult(tempIdentity,viewDTO.isAttendance());
AttendanceDraft attendanceDraft=atteDraftService.findDraft(viewDTO.getRegistrationNo(),viewDTO.getCourseId(),viewDTO.getYear(),viewDTO.getSemester(),viewDTO.getUserId());
if(attendanceDraft!=null){
attendanceDraft.setStatus(true);
atteDraftService.save(attendanceDraft);
//atteDraftService.delete(attendanceDraft);
tempResultRepository.save(tempResultUser);
return tempResultUser;
}
else{
throw new CustomException("No draft available");
}
}
}
The exception class
#ResponseStatus(code= HttpStatus.NOT_FOUND)
public class CustomException extends RuntimeException {
public CustomException(String message){
super(message);
}
}
The terminal in the intellij prints "No draft available ". But i want it not as an internal server error.
Can some one tell me how i should be handling these errors please?
I tried using the #RestControllerAdvice
#RestControllerAdvice
public class WebRestControllerAdvice {
#ExceptionHandler(CustomException.class)
public ResponseMsg handleNotFoundException(CustomException ex) {
ResponseMsg responseMsg = new ResponseMsg(ex.getMessage());
return responseMsg;
}
}
And this is my response message class
public class ResponseMsg {
private String message;
//getters and setters
}
This is another simple request in the application
#RequestMapping(value = "/user/view",method = RequestMethod.POST)
public ResponseEntity<?> getUser(#RequestBody UserDTO userDTO) throws CustomException{
User user=userService.findByUsername(userDTO.getUsername());
if(user!=null){
return ResponseEntity.ok(user);
}
//
throw new CustomException("User not found");
}
But still the custom exception is not thrown. The response body is empty. but intellij says "user not found" and postman returns the status code 500.
Spring boot has a very convenient way to handle exceptions in any layer of your application which is defining a #ControllerAdvice bean. Then you can throw any type of exception in your code and it will be "captured" on this class.
After this you can handle and return whatever your app needs to return.
By the way, you can return your custom object and it will be parsed to json automatically.
Documentation: https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/
Sample code:
#ControllerAdvice
public class ErrorHandler {
#ExceptionHandler(BadRequestException.class)
#ResponseStatus(HttpStatus.BAD_REQUEST)
#ResponseBody
public Object processValidationError(BadRequestException ex) {
//return whatever you need to return in your API
}
}
I am doing validation for request object in spring boot rest. I have to validate data type of request. The request has multiple boolean values and trying to validate if string in passed for boolean data type.
I have handling HttpMessageNotReadableException in my ControllerAdvice class and sending list of error message. But in my response only first field is throwing exception. If clue ,please help.
#Vishnu Dubey use this .....
#RestControllerAdvice
public class ServiceControllerAdvice {
private static final Logger log = LoggerFactory.getLogger(ServiceControllerAdvice.class);
#ExceptionHandler(value = { ConstraintViolationException.class })
#ResponseStatus(value = HttpStatus.BAD_REQUEST)
public ServiceResponse<?> constraintViolationException(final ConstraintViolationException ex) {
log.error("Validation failed", ex);
final ServiceResponse<?> response = new ServiceResponse<>(-1);
final Error error = new Error();
error.setCode("PS01");
error.setContext(ex);
error.setMessage(ex.getMessage());
response.setError(error);
return response;
}
}
I'm using Spring to create an API, but I'm having some trouble introducing custom error reporting on (a part of) the validation of the request body.
When parsing/validation errors occur, I want to give a custom response back to the user.
This works well for fields annotated with #Valid along with validators like #javax.validation.constraints.NotNull by using a custom ResponseEntityExceptionHandler annotated with #ControllerAdvice.
It does not work however if an Exception is thrown while parsing the request body (before the validations even run). In that case I get an html error page with status 500 (Server Error)
How can I make sure the exceptions during parsing lead to the same kind of response as the (custom) one I return for validation failures?
My endpoint's code looks like this:
#RequestMapping(value= "/endpoint"
produces = { "application/json" },
consumes = { "application/json" },
method = RequestMethod.POST)
default ResponseEntity<Object> postSomething(#Valid #RequestBody MyRequestBody requestData){
// ...
}
MyRequestBody class looks like this:
#Validated
public class MyRequestData {
#JsonProperty("stringValue")
private String stringValue = null;
#NotNull
#Valid
public String getStringValue() {
return stringValue;
}
// ...
public enum EnumValueEnum {
VALUE_1("value 1"),
VALUE_1("value 2");
private String value;
EnumValueEnum(String value) {
this.value = value;
}
#Override
#JsonValue
public String toString() {
return String.valueOf(value);
}
#JsonCreator
public static EnumValueEnum fromValue(String text) {
if(text == null){
return null;
}
for (EnumValueEnum b : EnumValueEnum.values()){
if (String.valueOf(b.value).equals(text)) {
return b;
}
}
throw new HttpMessageNotReadableException("EnumValueEnum \"" + text + "\" does not exist");
}
}
#JsonProperty("enumValue")
private EnumValueEnum enumValue = null;
}
The custom validation error handling (and reporting) looks like this:
#Order(Ordered.HIGHEST_PRECEDENCE)
#ControllerAdvice
public class MyValidationHandler extends ResponseEntityExceptionHandler {
#Override
protected ResponseEntity<Object> handleMethodArgumentNotValid(MethodArgumentNotValidException ex, HttpHeaders headers, HttpStatus status, WebRequest request) {
// return status(BAD_REQUEST).body(new ValidationResponse(ex.getBindingResult().getFieldErrors()));
}
#Override
protected ResponseEntity<Object> handleHttpMessageNotReadable(HttpMessageNotReadableException ex, HttpHeaders headers, HttpStatus status, WebRequest request) {
// return status(BAD_REQUEST).body(new ValidationResponse((JsonMappingException) ex.getCause()));
}
}
In this code, if a user sends a request with an enum value that doesn't exist, an HttpMessageNotReadableException is thrown. I would like to catch that somewhere and replace it with a custom response that is consistent with the other exception handling I do. Where/How can I do that?
I found a solution to my own problem.
You can actually use Spring MVC's normal exception handling:
Annotating a method with #ExceptionHandler will make Spring try to use it for exception handling for the exception type specified (in the annotation's value field or the method's argument). This method can be placed in the controller or even in the ResponseEntityExceptionHandler I use for the other validation response handling.
#ExceptionHandler
public ResponseEntity handle(HttpMessageConversionException e){
// return status(BAD_REQUEST).body(new ValidationResponse((JsonMappingException) e.getCause()));
}
Mind which type of exception you handle:
The catch here was that the exception thrown while parsing is wrapped in (some subtype of) a JsonMappingException which in turn is wrapped again in a HttpMessageConversionException.
e instanceof HttpMessageConversionException
e.getCause() instanceof JsonMappingException
e.getCause().getCause() // == your original exception
The #ExceptionHandler should therefor accept HttpMessageConversionException instead of the originally thrown exception (which in my case was HttpMessageNotReadableException)
It will not work if you write an #ExceptionHandler that only accepts your original Exception!
i have one REST API method :which will return Xml as response . Just for simplicity assume it throws simple Exception.
#RequestMapping(value = "machine/xmlData", method = RequestMethod.GET, produces = "application/xml")
public ResponseEntity<String> getXml(HttpServletRequest request)
throws Exception {
return getDataFromService();
}
Now i am handling the Exception in REST Controller like this.
This is generic Exception Handle method, for other API methods as well.(Xml or JSON Response)
#ExceptionHandler(Exception.class)
#ResponseStatus(value = HttpStatus.INTERNAL_SERVER_ERROR)
public ResponseEntity HandleException(Exception ex, HttpServletRequest request) {
ex.printStackTrace();
// here logic to generate Custom error Object
return new ResponseEntity<Object>(customErrorObject, HttpStatus.INTERNAL_SERVER_ERROR);
}
Case 1: Accept :"application/xml" and valid Response from Service
Everything works fine.
Case 2: Accept :"application/xml" and Exception from Service
then i get 406 Not Representable
As per my understanding it is
because ResponseEntity from HandleException is JSON and accept header
is "application/xml" thats why i am getting 406.
Is there anyway that i can send the error Response from HandleException method as xml and json ?
I know on REST API methods we can define something like this produces={"application/json","application/xml"} i am struggling to put this on HandleException Method.
Any tip would be of great help.
Thanks.
You could take advantage of the spring-mvc HttpMessageConverters by using the #ResponseBody annotation( https://spring.io/blog/2013/05/11/content-negotiation-using-spring-mvc). This annotation is responsible for choosing the correct messageConverter for a given response type.
For your response to be xml or json compatible you need to do the following:
#XmlRootElement
#XmlAccessorType(XmlAccessType.FIELD)
public class WrappedExceptionResponse {
public String respone;
public String getRespone() {
return respone;
}
public void setRespone(String respone) {
this.respone = respone;
}
}
And change your exception handler method to
#ExceptionHandler(Exception.class)
#ResponseStatus(value = HttpStatus.INTERNAL_SERVER_ERROR)
public #ResponseBody WrappedExceptionResponse HandleException(Exception ex, HttpServletRequest request) {
// ex.printStackTrace();
// here logic to generate Custom error Object
WrappedExceptionResponse resp=new WrappedExceptionResponse();
resp.setRespone(ex.getMessage());
return resp;
And then your exception response would be dependent on the content-type you give.
I have an API built with Spring Boot. By default the default JSON structure when an error is thrown by Spring is;
{
"timestamp": 1477425179601,
"status": 404,
"error": "Not Found",
"message": "No message available",
"path": "/categoriess"
}
This structure is different to error responses returning myself in the API, so I'd like to change Spring to use the same structure as my own for consistency.
My error response are structured like this;
{
"errors": [
{
"code": 999404,
"message": "The resource you were looking for could not be found"
}
]
}
How would I go about doing this? I've tried using an Exception Handler, but I can't figure out the correct exception to set it up for. I'd like to also make sure that the Http status is still correctly returned as 404, or whatever the error is (500 etc).
I had another look at this and did manage to put something together that works for me.
#Bean
public ErrorAttributes errorAttributes() {
return new DefaultErrorAttributes() {
#Override
public Map<String, Object> getErrorAttributes(RequestAttributes requestAttributes, boolean includeStackTrace) {
Map<String, Object> errorAttributes = super.getErrorAttributes(requestAttributes, includeStackTrace);
Map<String, Object> error = new HashMap<>();
error.put("code", errorAttributes.get("status"));
error.put("message", errorAttributes.get("error"));
Map<String, Object> errorResponse = new HashMap<>();
errorResponse.put("errors", error);
return errorResponse;
}
};
}
This returns the following JSON response along with whatever header/http status code spring was going to return.
{
"errors": {
"code": 404,
"message": "Not Found"
}
}
This seems to work great for errors generated by spring, while my own Exceptions I'm handling in Controllers or in a specific ControllerAdmin class with ExceptionHandlers.
A possible way to do something like this is to use the #ExceptionHandler annotation to create a handler method inside your controller.
#RestController
#RequestMapping(produces = APPLICATION_JSON_VALUE)
public class MyController {
#RequestMapping(value = "/find", method = GET)
public Object find() {
throw new UnsupportedOperationException("Not implemented yet!");
}
#ExceptionHandler
public ErrorListModel handleException(Exception exception) {
ExceptionModel exceptionModel = new ExceptionModel(1337, exception.getMessage());
ErrorListModel list = new ErrorListModel();
list.add(exceptionModel);
return list;
}
private class ErrorListModel {
private List<ExceptionModel> errors = new ArrayList<>();
public void add(ExceptionModel exception) {
errors.add(exception);
}
public List<ExceptionModel> getErrors() {
return errors;
}
}
private class ExceptionModel {
private int code;
private String message;
public ExceptionModel(int code, String message) {
this.code = code;
this.message = message;
}
public int getCode() {
return code;
}
public String getMessage() {
return message;
}
}
}
The private classes ErrorListModel and ExceptionModel just help defining how the resulting JSON body should look, and I assume you already have your own, similar classes.
The find method just throws an exception for us to handle, which gets intercepted by the handleException method because it's annotated with #ExceptionHandler. In here, we create an ExceptionModel, populate it with information from the original exception, and add it to an ErrorListModel, which we then return.
This blog post from 2013 explains the features better than I ever could, and it also mentions an additional option, #ControllerAdvice. It basically allows you to re-use the exception handling in other controllers as well.