I'm trying to show custom error pages depending on the HTTP status code. What I have done is implementing Spring's ErrorController interface in a CustomErrorController but it seems that Spring Boot is not recognizing it.
I have followed this tutorial to do that: https://www.baeldung.com/spring-boot-custom-error-page (section 3.1).
There I have read that first you need to get rid of the famous Spring's default Whitelabel Error Page. So I did this:
#SpringBootApplication(exclude = { ErrorMvcAutoConfiguration.class })
public class MyApplication {
public static void main(String[] args) {
SpringApplication.run(MyApplication.class, args);
}
}
This seems to work since the Whitelabel error page hasn't appeared anymore but now when an error happens the Apache Tomcat error page (that ugly one with the stack trace included) appears instead of mine.
Then I've just implemented my CustomErrorController like this:
#Controller
#RequestMapping("/error")
public class CustomErrorController implements ErrorController {
#RequestMapping
public String handleError(HttpServletRequest request) {
Integer statusCode = (Integer) request.getAttribute(RequestDispatcher.ERROR_STATUS_CODE);
if (statusCode != null) {
// Specific error page
return "redirect:/error/" + statusCode;
}
// Global error page
return "error/error";
}
#Override
public String getErrorPath() {
return "/error";
}
#GetMapping("/404")
public String notFoundErrorPage() {
return "error/404";
}
// Other error codes mapping methods
}
I'm using Thymeleaf and my error views are under src/main/resources/views/error, where every specific error page name follows the recommended format of <error_code>.html so, for instance, a 404 error would have a 404.html page associated.
I haven't had any problem with other application views resolving so far. Actually, I have configured my Spring Security to call the /error/403 endpoint if access denied occurs and the error page is shown properly.
Same happens with /error/500, that is called when an internal server exception occurs since I have also implemented the following #ControllerAdvice #ExceptionHandler method:
#ControllerAdvice
#Log4j2
public class GlobalDefaultExceptionHandler {
#ExceptionHandler(Exception.class)
public String defaultErrorHandler(Exception exception) throws Exception {
if (AnnotationUtils.findAnnotation(exception.getClass(), ResponseStatus.class) != null) {
throw exception;
}
log.catching(exception);
return "redirect:/error/500";
}
}
So, if each of these endpoints works individually, why if Spring throws an error the handleError method is not called ever?
Thank you.
Seems as if your GlobalDefaultExceptionHandler is catching every Exception upfront. That's why handleError is never called.
Your other endpoints work, cause you are calling them directly - as you describe it.
I would recommend using #ControllerAdvice to handle specific Exceptions an let your CustomErrorController implementation handle all not already handled Exceptions. Spring boot will wrap them inside NestedServletException with Http Status 500. You can get the root cause inside handleError with:
Object exception = request.getAttribute("javax.servlet.error.exception");
if (String.valueOf(exception) != null) {
log.info("Nested Exception: " + String.valueOf(exception));
}
Check those answers for further information on ordering and the error work flow in spring boot:
order
spring boot error handling flow
Related
When using Spring Boot, I am unsure if error handling is already being taken care of by the Spring Framework, or if I have to implement it. For example, consider a controller method, which handles a DELETE request:
#DeleteMapping("/{studentId}")
public ResponseEntity<Long> deleteProfilePicture(#PathVariable Long studentId) {
return ResponseEntity.ok(profilePictureService.deleteprofilePictureByStudentId(studentId));
}
Is this fine, or should I instead wrap it inside a try-catch block:
#DeleteMapping("/{studentId}")
public ResponseEntity<Long> deleteProfilePicture(#PathVariable Long studentId) throws Exception {
try {
profilePictureService.deleteProfilePictureByStudentId(studentId));
} catch (DataAccessException e) {
throw new Exception("cannot delete profile picture of student: " + studentId);
}
}
Also: If I let my method deleteProfilePicture throw this Exception, who is handling the Exception? This must somehow be taken care of by Spring Boot, since it is possible to implement it without yielding any errors. Anyhow, what is the correct way of error handling in this scenario?
Spring Boot will turn the exception into an error response to the caller of the REST API. This does not mean that you shouldn't implement your own error handling logic, which you definitely should. As an example, you could use #ControllerAdvice to have a global exception handling for your application. Something along the following lines:
#ControllerAdvice
#Slf4j
public class GlobalExceptionHandler extends ResponseEntityExceptionHandler {
#ExceptionHandler(value = {Exception.class})
public ResponseEntity<Object> handleGenericExceptions(Exception exception, WebRequest webRequest) {
log.error("Handling: ", exception);
HttpStatus errorCode = HttpStatus.INTERNAL_SERVER_ERROR;
return this.handleExceptionInternal(exception, new ErrorInfo(errorCode.value(), "Unexpected Internal Server Error"), new HttpHeaders(), errorCode, webRequest);
}
}
You can read more about error handling in Spring Boot at https://www.baeldung.com/exception-handling-for-rest-with-spring.
I was reading the article - https://www.baeldung.com/exception-handling-for-rest-with-spring
which says
Spring 5 introduced the ResponseStatusException class.
We can create an instance of it providing an HttpStatus and optionally
a reason and a cause:
I started implementing it , and the code is
custom exception
#ResponseStatus(code = HttpStatus.NOT_FOUND, reason = "Actor Not Found")
public class ActorNotFoundException extends Exception {
private static final long serialVersionUID = 1L;
public ActorNotFoundException(String errorMessage) {
super(errorMessage);
}
}
method in service
public String updateActor(int index, String actorName) throws ActorNotFoundException {
if (index >= actors.size()) {
throw new ActorNotFoundException("Actor Not Found in Repsoitory");
}
actors.set(index, actorName);
return actorName;
}
controller
#GetMapping("/actor/{id}")
public String getActorName(#PathVariable("id") int id) {
try {
return actorService.getActor(id);
} catch (ActorNotFoundException ex) {
throw new ResponseStatusException(HttpStatus.NOT_FOUND, "Actor Not Found", ex); //agreed it could be optional, but we may need original exception
}
}
repo:
https://github.com/eugenp/tutorials/tree/master/spring-5/src/main/java/com/baeldung/exception
Question:
why ResponseStatusException in controller again has to specify reason - "Actor Not Found" ?, as the service already said - ""Actor Not Found in Repsoitory"
What is the proper way to adapt to ResponseStatusException model?
It looks like a mistake. Ideally the service shouldn't use any HTTP code, so I would remove the annotation in ActorNotFoundException. Everything else seems fine, the exception is caught in the controller and ResponseStatusException is thrown which is good, because it's a proper layer to put HTTP stuff.
Overall it is better to use #ControllerAdvice instead of ResponseStatusException. it gives you a unified exception handling solution. Although it is not a good idea from a design point of view, ResponseStatusException can help you to avoid creating your custom exceptions and use it at the service level to throw in case of an Exception.
to avoid writing the message again you can use the message that is already available in thrown exception:
throw new ResponseStatusException(HttpStatus.NOT_FOUND, ex.getMessage() , ex);
for examples and more info you can refer to the following articles:
Spring Boot Exception Handling — #ControllerAdvice
Spring Boot Exception Handling — ResponseStatusException
due to this tutorial - https://www.baeldung.com/spring-boot-custom-error-page I wanted to customize my error page ie. when someone go to www.myweb.com/blablablalb3 I want to return page with text "wrong url request".
All works fine:
#Controller
public class ApiServerErrorController implements ErrorController {
#Override
public String getErrorPath() {
return "error";
}
#RequestMapping("/error")
public String handleError() {
return "forward:/error-page.html";
}
}
But I dont know how to test it:
#Test
public void makeRandomRequest__shouldReturnErrorPage() throws Exception {
this.mockMvc.perform(get(RANDOM_URL))
.andDo(print());
}
print() returns:
MockHttpServletResponse:
Status = 404
Error message = null
Headers = {X-Application-Context=[application:integration:-1]}
Content type = null
Body =
Forwarded URL = null
Redirected URL = null
Cookies = []
So I cant created something like this:
.andExpect(forwardedUrl("error-page"));
because it fails, but on manual tests error-page is returned.
Testing of a custom ErrorController with MockMvc is unfortunately not supported.
For a detailed explanation, see the official recommendation from the Spring Boot team (source).
To be sure that any error handling is working fully, it's necessary to
involve the servlet container in that testing as it's responsible for
error page registration etc. Even if MockMvc itself or a Boot
enhancement to MockMvc allowed forwarding to an error page, you'd be
testing the testing infrastructure not the real-world scenario that
you're actually interested in.
Our recommendation for tests that want to be sure that error handling
is working correctly, is to use an embedded container and test with
WebTestClient, RestAssured, or TestRestTemplate.
My suggestion is to use #ControllerAdvice
In this way you can work around the problem and you can continue to use MockMvc with the big advantage that you are not required to have a running server.
Of course to test explicitly the error page management you need a running server. My suggestion is mainly for those who implemented ErrorController but still want to use MockMvc for unit testing.
#ControllerAdvice
public class MyControllerAdvice {
#ExceptionHandler(FileSizeLimitExceededException.class)
public ResponseEntity<Throwable> handleFileException(HttpServletRequest request, FileSizeLimitExceededException ex) {
return new ResponseEntity<>(ex, HttpStatus.PAYLOAD_TOO_LARGE);
}
#ExceptionHandler(Throwable.class)
public ResponseEntity<Throwable> handleUnexpected(HttpServletRequest request, Throwable throwable) {
return new ResponseEntity<>(throwable, HttpStatus.INTERNAL_SERVER_ERROR);
}
}
I have implemented a Spring Rest Controller that streams back large files using the StreamingResponseBody. However, these files are coming from another system and there is the potential for something to go wrong while streaming them back. When this occurs I am throwing a custom Exception (MyException). I am handling the exception in an #ExceptionHandler implementation which is below. I am attempting to set the response httpstatus and error message but I am always receiving http status 406. What is the proper way to handle errors/exceptions while returning a StreamingResponseBody?
#ExceptionHandler(MyException.class)
public void handleParsException( MyException exception, HttpServletResponse response) throws IOException
{
response.sendError(HttpStatus.INTERNAL_SERVER_ERROR.value(),exception.getMessage());
}
You should handle all errors in the same way. There are many options.
I prefer next:
Controller Advice
It is a good idea to have an entity to send a generic error response, an example:
public class Error {
private String code;
private int status;
private String message;
// Getters and Setters
}
Otherwise, to handle exceptions you should create a class annotated with #ControllerAdvice and then create methods annotated with #ExceptionHandler and the exception or exceptions (it could be more than one) you want to handle. Finally return ResponseEntity<Error> with the status code you want.
public class Hanlder{
#ExceptionHandler(MyException.class)
public ResponseEntity<?> handleResourceNotFoundException(MyException
myException, HttpServletRequest request) {
Error error = new Error();
error.setStatus(HttpStatus.CONFLICT.value()); //Status you want
error.setCode("CODE");
error.setMessage(myException.getMessage());
return new ResponseEntity<>(error, null, HttpStatus.CONFLICT);
}
#ExceptionHandler({DataAccessException.class, , OtherException.class})
public ResponseEntity<?> handleResourceNotFoundException(Exception
exception, HttpServletRequest request) {
Error error = new Error();
error.setStatus(HttpStatus.INTERNAL_ERROR.value()); //Status you want
error.setCode("CODE");
error.setMessage(myException.getMessage());
return new ResponseEntity<>(error, null, HttpStatus.INTERNAL_ERROR);
}
}
Other ways:
Annotate exception directly
Other way is annotating directly the excetion with the status and the reason to return:
#ResponseStatus(value=HttpStatus.CONFLICT, reason="Error with StreamingResponseBody")
public class MyError extends RuntimeException {
// Impl ...
}
Exception Handler in a specific controller
Use a method annotated with #ExceptionHandler in a method of a #Controller to handle #RequestMapping exceptions:
#ResponseStatus(value=HttpStatus.CONFLICT,
reason="Error with StreamingResponse Body")
#ExceptionHandler(MyError.class)
public void entitiyExists() {
}
I figured the problem out. The client was only accepting the file type as an acceptable response. Therefore, when returning an error in the form of an html page I was getting httpstatus 406. I just needed to tell the client to accept html as well to display the message.
I am not able to override default spring boot error response in REST api. I have following code
#ControllerAdvice
#Controller
class ExceptionHandlerCtrl {
#ResponseStatus(value=HttpStatus.UNPROCESSABLE_ENTITY, reason="Invalid data")
#ExceptionHandler(BusinessValidationException.class)
#ResponseBody
public ResponseEntity<BusinessValidationErrorVO> handleBusinessValidationException(BusinessValidationException exception){
BusinessValidationErrorVO vo = new BusinessValidationErrorVO()
vo.errors = exception.validationException
vo.msg = exception.message
def result = new ResponseEntity<>(vo, HttpStatus.UNPROCESSABLE_ENTITY);
result
}
Then in my REST api I am throwing this BusinessValidationException. This handler is called (I can see it in debugger) however I still got default spring boot REST error message. Is there a way to override and use default only as fallback? Spring Boot version 1.3.2 with groovy. Best Regards
Remove #ResponseStatus from your method. It creates an undesirable side effect and you don't need it, since you are setting HttpStatus.UNPROCESSABLE_ENTITY in your ResponseEntity.
From the JavaDoc on ResponseStatus:
Warning: when using this annotation on an exception class, or when setting the reason attribute of this annotation, the HttpServletResponse.sendError method will be used.
With HttpServletResponse.sendError, the response is considered complete and should not be written to any further. Furthermore, the Servlet container will typically write an HTML error page therefore making the use of a reason unsuitable for REST APIs. For such cases it is preferable to use a ResponseEntity as a return type and avoid the use of #ResponseStatus altogether.
I suggest you to read this question: Spring Boot REST service exception handling
There you can find some examples that explain how to combine ErrorController/ ControllerAdvice in order to catch any exception.
In particular check this answer:
https://stackoverflow.com/a/28903217/379906
You should probably remove the annotation #ResponseStatus from the method handleBusinessValidationException.
Another way that you have to rewrite the default error message is using a controller with the annotation #RequestMapping("/error"). The controller must implement the ErrorController interface.
This is the error controller that I use in my app.
#RestController
#RequestMapping("/error")
public class RestErrorController implements ErrorController
{
private final ErrorAttributes errorAttributes;
#Autowired
public MatemoErrorController(ErrorAttributes errorAttributes) {
Assert.notNull(errorAttributes, "ErrorAttributes must not be null");
this.errorAttributes = errorAttributes;
}
#Override
public String getErrorPath() {
return "/error";
}
#RequestMapping
public Map<String, Object> error(HttpServletRequest aRequest) {
return getErrorAttributes(aRequest, getTraceParameter(aRequest));
}
private boolean getTraceParameter(HttpServletRequest request) {
String parameter = request.getParameter("trace");
if (parameter == null) {
return false;
}
return !"false".equals(parameter.toLowerCase());
}
private Map<String, Object> getErrorAttributes(HttpServletRequest aRequest, boolean includeStackTrace)
{
RequestAttributes requestAttributes = new ServletRequestAttributes(aRequest);
return errorAttributes.getErrorAttributes(requestAttributes, includeStackTrace);
} }