Get exception object in custom error controller - spring-boot

I am using spring boot and write a global exception handler use AbstractErrorController. How could i get an exception object in controller?
#Controller
public class MyCustomErrorController extends AbstractErrorController {
public MyCustomErrorController(ErrorAttributes errorAttributes) {
super(errorAttributes);
}
#RequestMapping("/error")
public void handleError(HttpServletRequest req, HttpServletResponse resp) {
Exception e = ...; // how to get exception here
log.error(e);
displayError(req, resp, e);
}
#Override
public String getErrorPath() {
return "/error";
}
}

You can get the exception from the HttpServletRequest as follows:
#Controller
public class MyCustomErrorController extends AbstractErrorController {
#RequestMapping("/error")
public void handleError(HttpServletRequest request) {
Exception e = (Exception) request.getAttribute(RequestDispatcher.ERROR_EXCEPTION);
...
}
}

An handler intercepts an Exception generated or re-thrown by a controller. It doesn't have an endpoint because it usually does it for all the controllers in your application. The Handler instructs the application server to return a specific error when a specific Exception is thrown.
Here is an example:
#ControllerAdvice // Specialization of #Component for classes that declare #ExceptionHandler, #InitBinder, or #ModelAttribute methods to be shared across multiple #Controller classes.
public class ResourceNotFoundExceptionHandler {
#ExceptionHandler(value = { ResourceNotFoundException.class })
public ResponseEntity<Object> handleResourceNotFoundException(ResourceNotFoundException ex, WebRequest request) {
ApiError error = new ApiError(HttpStatus.NOT_FOUND, ex.getLocalizedMessage(), ex);
HttpHeaders headers = new HttpHeaders();
headers.setContentType(MediaType.APPLICATION_JSON_UTF8);
ResponseEntity<Object> response = new ResponseEntity<>(error, headers, HttpStatus.NOT_FOUND);
return response;
}
}
In this example ApiError is a data structure that reports the error to the UI. What this code does is intercepting the Exception "ResourceNotFoundException", create an appropriate error Data transfer object, set the response HttpStatus and headers and return the error.
you can find a different example here: https://github.com/otrebor/springbootseed-openshift/blob/master/src/main/java/com/company/example/springbootseed/core/errorhandling/handlers/

Add Exception as an extra parameter to handleError()

Related

Make Spring's #RequestBody annotation return a custom response on-fail

I have a controller as follows:
public void createEntity(#Valid #RequestBody final MyEntity myEntity) {}
However, when the object transformation fails, the API automatically returns a 400 with the Java stack trace. How can I modify this on-failure response? (I wish to change or remove the response message).
Here is an example how to do this with an #ExceptionHandler annotation
#RestController
public class Controller {
#RequestMapping(value = "/", method = RequestMethod.POST)
public void createEntity(#Valid #RequestBody final MyEntity myEntity) {
//
}
#ControllerAdvice
public class RestEndpointExceptionHandler {
#ExceptionHandler(MethodArgumentNotValidException.class)
public ResponseEntity<Object> handleNotValidExceptionException(HttpServletRequest req, MethodArgumentNotValidException ex) {
Object customException = "Validation failed";
return new ResponseEntity<Object>(customException, HttpStatus.BAD_REQUEST);
}
}
}
I pushed the code in here
You can use #ExceptionHandler with #ResponseStatus and leave handler empty so that only Status Code is returned back.
#ExceptionHandler(EmptyResultDataAccessException.class)
#ResponseStatus(HttpStatus.NOT_FOUND)
public void notFoundException() {
}

How to validated rest url in spring boot?

validate Rest URL in spring boot.
Requirement: If I hit the wrong URL then it should throw a custom exception.
ex. Correct URL is "/fulfillment/600747l/send_to_hub" If I hit "/api/600747l/send_to_hub_1" then it should return exception like
"404:- URL not Found.".
Right now it returning "500 : -
{
"timestamp": 1531995246549,
"status": 500,
"error": "Internal Server Error",
"message": "Invalid Request URL.",
"path": "/api/600747l/send_to_hub_1"
}"
you need to write NewClass with annotation #ControllerAdvice which will redirect all exceptions to this NewClass.
example
Your Custom Exception Class:
#Data
#AllArgsConstructor
#EqualsAndHashCode(callSuper = false)
public class IOApiException extends IOException {
private ErrorReason errorReason;
public IOApiException(String message, ErrorReason errorReason) {
super(message);
this.errorReason = errorReason;
}
}
Now the CustomExceptionHandler Class -
#ControllerAdvice
#RestController
public class GlobalExceptionHandler {
Logger logger = LoggerFactory.getLogger(this.getClass());
#ResponseStatus(HttpStatus.UNAUTHORIZED)
#ExceptionHandler(value = IOApiException.class)
public GlobalErrorResponse handleException(IOApiException e) {
logger.error("UNAUTHORIZED: ", e);
return new GlobalErrorResponse("URL Not Found", HttpStatus.UNAUTHORIZED.value(), e.getErrorReason());
}
//this to handle customErrorResponseClasses
public GlobalErrorResponse getErrorResponseFromGenericException(Exception ex) {
if (ex == null) {
return handleException(new Exception("INTERNAL_SERVER_ERROR"));
}
else if (ex instanceof IOApiException) {
return handleException((IOApiException) ex);
}
}
Now Your error response class:
public class GlobalErrorResponse {
private String message;
#JsonIgnore
private int statusCode;
private ErrorReason reason;
}
ErrorReason Class
public enum ErrorReason {
INTERNAL_SERVER_ERROR,
INVALID_REQUEST_PARAMETER,
INVALID_URL
}
add and register one filter who calls the GlobalExceptionHandler in exception case like this
public class ExceptionHandlerFilter implements Filter {
private final GlobalExceptionHandler globalExceptionHandler;
public ExceptionHandlerFilter(GlobalExceptionHandler globalExceptionHandler) {
this.globalExceptionHandler = globalExceptionHandler;
}
#Override
public void init(FilterConfig filterConfig) throws ServletException {
}
#Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
try {
chain.doFilter(request, response);
} catch (Exception exception) {
HttpServletResponse httpResponse = (HttpServletResponse) response;
GlobalErrorResponse errorResponse = globalExceptionHandler.getErrorResponseFromGenericException(exception);
httpResponse.setStatus(errorResponse.getStatusCode());
response.getWriter().write(new ObjectMapper().writeValueAsString(errorResponse));
}
}
#Override
public void destroy() {
}
}
Like this you can add as many exceptions you want.. and can handle it manually.
As per your question first of all you need to define a base url(e.g.-/api) so that any url must be handled through your controller.Now after base url as shown /api/600747l/send_to_hub_1 #PathVariable int id. This circumstance is important, because Spring documentation said that if method argument annotated with #PathVariable can’t be casted to specified type (in our case to int), it will be exposed as String. Hence it can cause a TypeMismatchException.
To handle this I will use #ExceptionHandler annotation on #Controller level. Such approach suits for this situation as no one else. I just need to make 2 changes in the Controller:
1.Add MessageSource field
2.Add exception handler method
#Autowired
private MessageSource messageSource;
...
#ExceptionHandler(TypeMismatchException.class)
#ResponseStatus(value=HttpStatus.NOT_FOUND)
#ResponseBody
public ErrorInfo handleTypeMismatchException(HttpServletRequest req, TypeMismatchException ex) {
Locale locale = LocaleContextHolder.getLocale();
String errorMessage = messageSource.getMessage("error.bad.smartphone.id", null, locale);
errorMessage += ex.getValue();
String errorURL = req.getRequestURL().toString();
return new ErrorInfo(errorURL, errorMessage);
}
...

Spring validation returns long error messages, not just the customized message

Spring validation returns long error message instead of the customized once.
This is the section of code in the dto.
public class RequestDto implements Serializable {
#NotNull(message="{id.required}")
private Long id;
}
In controller added the #Valid for input.
#RequestMapping(value = ApiPath.PATH, method = RequestMethod.POST, produces = { "application/xml",
"application/json" })
public #ResponseBody ResultDecorator saveRequest(
#Valid #RequestBody RequestDto msaDisabScreenRequestDto) throws Exception {
}
API returns the following error.
<message>Validation failed for argument at index 0 in method: public om.gov.moh.msa.framework.resolver.ResultDecorator om.controller.MaController.saveRequest(om..dto.RequestDto) throws java.lang.Exception, with 1 error(s): [Field error in object 'requestDto' on field 'id': rejected value [null]; codes [NotNull.requestDto.id,NotNull.id,NotNull.java.lang.Long,NotNull]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [requestDto.id,id]; arguments []; default message [civilId]]; **default message [ID is required.]]** </message>
Here the custom message is present at the end. (default message [ID is required.)
Using Controller advice for global exception and I'm overriding handleMethodArgumentNotValid. How can I return only the custom message here?
#Order(Ordered.HIGHEST_PRECEDENCE)
#ControllerAdvice
public class RestExceptionHandler extends ResponseEntityExceptionHandler {
/**
* Spring validation related exception
*/
#Override
protected ResponseEntity<Object> handleMethodArgumentNotValid(
MethodArgumentNotValidException ex,
HttpHeaders headers,
HttpStatus status,
WebRequest request) {
ApiError apiError = new ApiError(HttpStatus.BAD_REQUEST);
apiError.setMessage(ex.getMessage());
return buildResponseEntity(apiError);
}
}
You can get default/custom message like result.getFieldError("yourFieldName").getDefaultMessage()
You can catch error messages either through controller method which should look like this
#RequestMapping(value = ApiPath.PATH, method = RequestMethod.POST, produces = { "application/xml", "application/json" })
public #ResponseBody ResultDecorator saveRequest(#Valid #RequestBody RequestDto msaDisabScreenRequestDto, BindingResult result) throws Exception {
if(result.hasErrors()){
String errorMessage = result.getFieldError("yourFieldName").getDefaultMessage();
}
}
Or through Global Exception handler
Updated
#Order(Ordered.HIGHEST_PRECEDENCE)
#ControllerAdvice
public class RestExceptionHandler extends ResponseEntityExceptionHandler {
/**
* Spring validation related exception
*/
#Override
protected ResponseEntity<Object> handleMethodArgumentNotValid(
MethodArgumentNotValidException ex,
HttpHeaders headers,
HttpStatus status,
WebRequest request) {
//New Code
BindingResult bindingResult = ex.getBindingResult();
String errorMessage = result.getFieldError("yourFieldName").getDefaultMessage();
//---------------
ApiError apiError = new ApiError(HttpStatus.BAD_REQUEST);
apiError.setMessage(errorMessage);
return buildResponseEntity(apiError);
}
}
Thanks Afridi,
Created a string buffer and added all the error messages into that.
/**
* Spring validation related exception
*/
#Override
protected ResponseEntity<Object> handleMethodArgumentNotValid(
MethodArgumentNotValidException ex,
HttpHeaders headers,
HttpStatus status,
WebRequest request) {
final StringBuffer errors = new StringBuffer();
ApiError apiError = new ApiError(HttpStatus.BAD_REQUEST);
for (final FieldError error : ex.getBindingResult().getFieldErrors()) {
errors.append("\n");
errors.append(error.getField() + ": " + error.getDefaultMessage());
}
apiError.setMessage(errors.toString());
return buildResponseEntity(apiError);
}
As Afridi said in #ControllerAdvice can do this also:
#ExceptionHandler(value = MethodArgumentNotValidException.class)
#SuppressWarnings("unchecked")
#ResponseBody
public Result methodArgumentNotValidExceptionHandler(HttpServletRequest req, HttpServletResponse response, MethodArgumentNotValidException e) throws IOException {
String message = e.getBindingResult().getAllErrors().get(0).getDefaultMessage();
// todo return to your custom result
}
There are two point :
Exception class is MethodArgumentNotValidException
The first Error getDefaultMessage() can get your custom message in Annotation
In WebFlux :
Handle WebExchangeBindException for customising the default error message of #Valid
#ControllerAdvice
public class ValidationHandler {
#ExceptionHandler(WebExchangeBindException.class)
public ResponseEntity<List<String>> handleException(WebExchangeBindException e) {
var errors = e.getBindingResult()
.getAllErrors()
.stream()
.map(DefaultMessageSourceResolvable::getDefaultMessage)
.collect(Collectors.toList());
return ResponseEntity.badRequest().body(errors);
}
}
Reference : https://www.vinsguru.com/spring-webflux-validation/

Spring-MVC Exception handler returns OK when writing into response

I'm using spring-webmvc : 3.2.3.RELEASE (and its related dependencies).
I have this controller:
#Controller
#RequestMapping("/home")
public class HomeController {
#Autowired
MappingJacksonHttpMessageConverter messageConverter;
#RequestMapping(method = RequestMethod.GET)
public String get() {
throw new RuntimeException("XXXXXX");
}
#ExceptionHandler(value = java.lang.RuntimeException.class)
#ResponseStatus(HttpStatus.CONFLICT)
public ModelAndView runtimeExceptionAndView(ServletWebRequest webRequest) throws Exception {
ModelAndView retVal = handleResponseBody("AASASAS", webRequest);
return retVal;
}
#SuppressWarnings({ "resource", "rawtypes", "unchecked" })
private ModelAndView handleResponseBody(Object body, ServletWebRequest webRequest) throws ServletException, IOException {
ServletServerHttpResponse outputMessage = new ServletServerHttpResponse(webRequest.getResponse());
messageConverter.write(body, MediaType.APPLICATION_JSON, outputMessage);
return new ModelAndView();
}
}
since the "/home" method throws RuntimeException that is being handled with the #ExceptionHandler, when the get() method is invoked, I'm expectin to get HttpStatus.CONFLICT, but instead, I'm getting HttpStatus.OK.
Can someone please tell me what should I do in order to get the response status from
the annotated exception handler?
The reason is because you are explicitly writing to the output stream, instead of letting the framework handle it. The header has to go before the body content is written, if you are explicitly handling writing to the output stream, you will have to write the header also yourself.
To let the framework handle the entire flow, you can instead do this:
#ExceptionHandler(value = java.lang.RuntimeException.class)
#ResponseStatus(HttpStatus.CONFLICT)
#ResponseBody
public TypeToBeMarshalled runtimeExceptionAndView(ServletWebRequest webRequest) throws Exception {
return typeToBeMarshalled;
}
Modify ExceptionHandler method like this
#ExceptionHandler(value = java.lang.RuntimeException.class)
public ModelAndView runtimeExceptionAndView(ServletWebRequest webRequest, HttpServletResponse response) throws Exception {
response.setStatus(HttpStatus.CONFLICT.value());
ModelAndView retVal = handleResponseBody("AASASAS", webRequest);
return retVal;
}
If you want to handle exception by json result, I suggest to use #ResponseBody with Automatic Json return.
#ExceptionHandler(value = java.lang.RuntimeException.class)
#ResponseBody
public Object runtimeExceptionAndView(ServletWebRequest webRequest, HttpServletResponse response) throws Exception {
response.setStatus(HttpStatus.CONFLICT.value());
return new JsonResult();
}

Spring MVC - RestTemplate launch exception when http 404 happens

I have a rest service which send an 404 error when the resources is not found.
Here the source of my controller and the exception which send Http 404.
#Controller
#RequestMapping("/site")
public class SiteController
{
#Autowired
private IStoreManager storeManager;
#RequestMapping(value = "/stores/{pkStore}", method = RequestMethod.GET, produces = "application/json")
#ResponseBody
public StoreDto getStoreByPk(#PathVariable long pkStore) {
Store s = storeManager.getStore(pkStore);
if (null == s) {
throw new ResourceNotFoundException("no store with pkStore : " + pkStore);
}
return StoreDto.entityToDto(s);
}
}
#ResponseStatus(value = HttpStatus.NOT_FOUND)
public class ResourceNotFoundException extends RuntimeException
{
private static final long serialVersionUID = -6252766749487342137L;
public ResourceNotFoundException(String message) {
super(message);
}
}
When i try to call it with RestTemplate with this code :
ResponseEntity<StoreDto> r = restTemplate.getForEntity(url, StoreDto.class, m);
System.out.println(r.getStatusCode());
System.out.println(r.getBody());
I receive this exception :
org.springframework.web.client.RestTemplate handleResponseError
ATTENTION: GET request for "http://........./stores/99" resulted in 404 (Introuvable); invoking error handler
org.springframework.web.client.HttpClientErrorException: 404 Introuvable
I was thinking I can explore my responseEntity Object and do some things with the statusCode. But exception is launch and my app go down.
Is there a specific configuration for restTemplate to not send exception but populate my ResponseEntity.
As far as I'm aware, you can't get an actual ResponseEntity, but the status code and body (if any) can be obtained from the exception:
try {
ResponseEntity<StoreDto> r = restTemplate.getForEntity(url, StoreDto.class, m);
}
catch (final HttpClientErrorException e) {
System.out.println(e.getStatusCode());
System.out.println(e.getResponseBodyAsString());
}
RESTTemplate is quite deficient in this area IMO. There's a good blog post here about how you could possibly extract the response body when you've received an error:
http://springinpractice.com/2013/10/07/handling-json-error-object-responses-with-springs-resttemplate
As of today there is an outstanding JIRA request that the template provides the possibility to extract the response body:
https://jira.spring.io/browse/SPR-10961
The trouble with Squatting Bear's answer is that you would have to interrogate the status code inside the catch block eg if you're only wanting to deal with 404's
Here's how I got around this on my last project. There may be better ways, and my solution doesn't extract the ResponseBody at all.
public class ClientErrorHandler implements ResponseErrorHandler
{
#Override
public void handleError(ClientHttpResponse response) throws IOException
{
if (response.getStatusCode() == HttpStatus.NOT_FOUND)
{
throw new ResourceNotFoundException();
}
// handle other possibilities, then use the catch all...
throw new UnexpectedHttpException(response.getStatusCode());
}
#Override
public boolean hasError(ClientHttpResponse response) throws IOException
{
return response.getStatusCode().series() == HttpStatus.Series.CLIENT_ERROR
|| response.getStatusCode().series() == HttpStatus.Series.SERVER_ERROR;
}
The ResourceNotFoundException and UnexpectedHttpException are my own unchecked exceptions.
The when creating the rest template:
RestTemplate template = new RestTemplate();
template.setErrorHandler(new ClientErrorHandler());
Now we get the slightly neater construct when making a request:
try
{
HttpEntity response = template.exchange("http://localhost:8080/mywebapp/customer/100029",
HttpMethod.GET, requestEntity, String.class);
System.out.println(response.getBody());
}
catch (ResourceNotFoundException e)
{
System.out.println("Customer not found");
}
Since it's 2018 and I hope that when people say "Spring" they actually mean "Spring Boot" at least, I wanted to expand the given answers with a less dust-covered approach.
Everything mentioned in the previous answers is correct - you need to use a custom ResponseErrorHandler.
Now, in Spring Boot world the way to configure it is a bit simpler than before.
There is a convenient class called RestTemplateBuilder. If you read the very first line of its java doc it says:
Builder that can be used to configure and create a RestTemplate.
Provides convenience methods to register converters, error handlers
and UriTemplateHandlers.
It actually has a method just for that:
new RestTemplateBuilder().errorHandler(new DefaultResponseErrorHandler()).build();
On top of that, Spring guys realized the drawbacks of a conventional RestTemplate long time ago, and how it can be especially painful in tests. They created a convenient class, TestRestTemplate, which serves as a wrapper around RestTemplate and set its errorHandler to an empty implementation:
private static class NoOpResponseErrorHandler extends
DefaultResponseErrorHandler {
#Override
public void handleError(ClientHttpResponse response) throws IOException {
}
}
You can create your own RestTemplate wrapper which does not throw exceptions, but returns a response with the received status code. (You could also return the body, but that would stop being type-safe, so in the code below the body remains simply null.)
/**
* A Rest Template that doesn't throw exceptions if a method returns something other than 2xx
*/
public class GracefulRestTemplate extends RestTemplate {
private final RestTemplate restTemplate;
public GracefulRestTemplate(RestTemplate restTemplate) {
super(restTemplate.getMessageConverters());
this.restTemplate = restTemplate;
}
#Override
public <T> ResponseEntity<T> getForEntity(URI url, Class<T> responseType) throws RestClientException {
return withExceptionHandling(() -> restTemplate.getForEntity(url, responseType));
}
#Override
public <T> ResponseEntity<T> postForEntity(URI url, Object request, Class<T> responseType) throws RestClientException {
return withExceptionHandling(() -> restTemplate.postForEntity(url, request, responseType));
}
private <T> ResponseEntity<T> withExceptionHandling(Supplier<ResponseEntity<T>> action) {
try {
return action.get();
} catch (HttpClientErrorException ex) {
return new ResponseEntity<>(ex.getStatusCode());
}
}
}
Recently had a usecase for this. My solution:
public class MyErrorHandler implements ResponseErrorHandler {
#Override
public boolean hasError(ClientHttpResponse clientHttpResponse) throws IOException {
return hasError(clientHttpResponse.getStatusCode());
}
#Override
public void handleError(ClientHttpResponse clientHttpResponse) throws IOException {
HttpStatus statusCode = clientHttpResponse.getStatusCode();
MediaType contentType = clientHttpResponse
.getHeaders()
.getContentType();
Charset charset = contentType != null ? contentType.getCharset() : null;
byte[] body = FileCopyUtils.copyToByteArray(clientHttpResponse.getBody());
switch (statusCode.series()) {
case CLIENT_ERROR:
throw new HttpClientErrorException(statusCode, clientHttpResponse.getStatusText(), body, charset);
case SERVER_ERROR:
throw new HttpServerErrorException(statusCode, clientHttpResponse.getStatusText(), body, charset);
default:
throw new RestClientException("Unknown status code [" + statusCode + "]");
}
}
private boolean hasError(HttpStatus statusCode) {
return (statusCode.series() == HttpStatus.Series.CLIENT_ERROR ||
statusCode.series() == HttpStatus.Series.SERVER_ERROR);
}
There is no such class implementing ResponseErrorHandler in Spring framework, so I just declared a bean:
#Bean
public RestTemplate getRestTemplate() {
return new RestTemplateBuilder()
.errorHandler(new DefaultResponseErrorHandler() {
#Override
public void handleError(ClientHttpResponse response) throws IOException {
//do nothing
}
})
.build();
}
The best way to make a RestTemplate to work with 4XX/5XX errors without throwing exceptions I found is to create your own service, which uses RestTemplate :
public ResponseEntity<?> makeCall(CallData callData) {
logger.debug("[makeCall][url] " + callData.getUrl());
logger.debug("[makeCall][httpMethod] " + callData.getHttpMethod());
logger.debug("[makeCall][httpEntity] " + callData.getHttpEntity());
logger.debug("[makeCall][class] " + callData.getClazz());
logger.debug("[makeCall][params] " + callData.getQueryParams());
ResponseEntity<?> result;
try {
result = restTemplate.exchange(callData.getUrl(), callData.getHttpMethod(), callData.getHttpEntity(),
callData.getClazz(), callData.getQueryParams());
} catch (RestClientResponseException e) {
result = new ResponseEntity<String>(e.getResponseBodyAsString(), e.getResponseHeaders(), e.getRawStatusCode());
}
return result;
}
And in case of exception, simply catch it and create your own ResponseEntity.
This will allow you to work with the ResponseEntity object as excepted.

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