#RestControllerAdvice vs #ControllerAdvice - spring

What are the major difference between #RestControllerAdvice and #ControllerAdvice ??
Is it we should always use #RestControllerAdvice for rest services and #ControllerAdvice MVC ?

#RestControllerAdvice is just a syntactic sugar for #ControllerAdvice + #ResponseBody, you can look here.
Is it we should always use #RestControllerAdvice for rest services and
#ControllerAdvice MVC?
Again, as mentioned above, #ControllerAdvice can be used even for REST web services as well, but you need to additionally use #ResponseBody.

In addition, we can just understand it as:
#RestControler = #Controller + #ResponseBody
#RestControllerAdvice = #ControllerAdvice + #ResponseBody.
Keeping in mind that #RestControllerAdvice is more convenient annotation for handling Exception with RestfulApi.
Example os usage:
#RestControllerAdvice
public class WebRestControllerAdvice {
#ExceptionHandler(CustomNotFoundException.class)
public ResponseMsg handleNotFoundException(CustomNotFoundException ex) {
ResponseMsg responseMsg = new ResponseMsg(ex.getMessage());
return responseMsg;
}
}
In that case any exception instanceOf CustomNotFoundException will be thrown in body of response.
Example extracted here:
https://grokonez.com/spring-framework/spring-mvc/use-restcontrolleradvice-new-features-spring-framework-4-3

Exception: A good REST API should handle the exception properly and send the proper response to the user. The user should not be rendered with any unhandled exception.
A REST API developer will have two requirements related to error handling.
Common place for Error handling
Similar Error Response body with a proper HTTP status code across APIs
#RestControllerAdvice is the combination of both #ControllerAdvice and #ResponseBody
The #ControllerAdvice annotation was first introduced in Spring 3.2.
We can use the #ControllerAdvice annotation for handling exceptions in the RESTful Services but we need to add #ResponseBody separately.
Note:
GlobalExceptionHandler was annotated with #ControllerAdvice, thus it is going to intercept exceptions from controllers accross the application.

The differences between #RestControllerAdvice and #ControllerAdvice is :
#RestControllerAdvice = #ControllerAdvice + #ResponseBody. - we can
use in REST web services.
#ControllerAdvice - We can use in both MVC and Rest web services, need to
provide the ResponseBody if we use this in Rest web services.
For Example :
Exception Class:
#ResponseStatus(value = HttpStatus.NOT_FOUND)
public class ResourceNotFoundException extends Exception{
private static final long serialVersionUID = 1L;
public ResourceNotFoundException(String message){
super(message);
}
}
usage of the above exception in Rest Web Service.
#RestControllerAdvice
public class MyRestControllerAdviceHandler {
#ExceptionHandler(ResourceNotFoundException.class)
public ResponseMsg resourceNotFoundException(ResourceNotFoundException ex) {
ResponseMsg resMsg = new ResponseMsg(ex.getMessage());
return resMsg;
}
}
usage of the above exception in MVC.
#ControllerAdvice
public class GlobalExceptionHandler extends ResponseEntityExceptionHandler {
#ExceptionHandler(ResourceNotFoundException.class)
public ResponseEntity<?> resourceNotFoundException(ResourceNotFoundException ex) {
return new ResponseEntity<>(ex.getMessage(), HttpStatus.NOT_FOUND);
}
}

If you use #ControllerAdvice and return your error object from a method then it will look for a view with the name of your error object so instead of returning the expected response it will return 404 for not founding a view page with that name
#ControllerAdvice
public class CustomizedExceptionHandler {
#ExceptionHandler({ UserNotFoundException.class })
#ResponseStatus(code = HttpStatus.BAD_REQUEST)
public ExceptionResponce handleUserNotException(Exception ex, WebRequest request) throws Exception {
ExceptionResponce exceptionResponce = new ExceptionResponce(new Date(), ex.getMessage(),
request.getDescription(false));
return exceptionResponce;
}
}
As in the above code, I want to return 400 (BAD_REQUEST) but
instead of 400, it is returning 404(NOT_FOUND)
You can solve this issue by using any of the below ways
add #ResponseBody to your method or class.
Use #RestControllerAdvice.
Or you can wrap your error object in ResponseEntity.
After using either of the above ways it returns the correct response

Related

Http status code from a global #ExceptionHandler with the #ControllerAdvice annotation

I'm implementing a global exception handler inside a Spring Boot App, with the #ControllerAdvice annotation, and I'd like to know, how could I get the http status code for showing a different message when it's 404 and to persist a log with the error, in other cases.
This is a simplified version of the code:
#ControllerAdvice
public class GlobalExceptionHandler {
#ExceptionHandler(RuntimeException.class)
public ModelAndView handleException(Exception ex, HttpServletRequest request, HttpServletResponse response) {
...
ModelAndView model = new ModelAndView();
model.addObject("message", ex.getMessage());
model.addObject("trace", trace);
model.addObject("path", path);
//model.addObject("status", response.getStatus());
model.setViewName("error");
return model;
}
I've tried this approach, without success:
Object status = request.getAttribute(RequestDispatcher.ERROR_STATUS_CODE);
Integer statusCode = Integer.valueOf(status.toString());
To get the request attribute, this other name; javax.servlet.error.status_code doesn't work either.
You have to set your own status code corresponding every exception that you are handling. If any exception missed, default will be 5.x.x server error.
I remember doing this by extracting the expected exception to a separate class that extends Exception.
By doing this, you can add #ResponseStatus to set your required status code.
This custom exception can be thrown in your controller needed.
#ResponseStatus(value=HttpStatus.NOT_FOUND, reason="Person Not Found")
public class PersonNotFoundException extends Exception {
public PersonNotFoundException (int id){
super("PersonNotFoundException with id="+id);
}
}
Instead of specifying the generic RunTime exception, handle the PersonNotFoundException in your #ExceptionHandler and add the exception object to your ModelAndView.

Spring MVC - ExceptionHandler

I am using Spring Boot 1.5.7.
I have an ExceptionHandler for my exception that returns a ResponseEntity
#ExceptionHandler(MyException.class)
public ResponseEntity<ResponseExceptionEntity> handleException(MyException e) {
return ResponseEntity
.status(HttpStatus.BAD_REQUEST)
.body(new ResponseExceptionEntity(e));
}
This works well in situations where the exception occurs during an api call returning a ResponseEntity / #ResponseBody (JSON/XML response)
I would like to return a ModelAndView in situations where the exception occurs during a request where HTML is returned. In my situation all Controllers are annotated with #Controller and not #RestController
how can I write a ExceptionHandler for both cases (api/html)?
Or How can I determine what the resolved view is for a controller method?
Or how can I determine what the return type of the Controller Method
is?
Or How can I determine what the resolved view is for the controller
method?
I've tried the suggestion in this answer, but it doesn't return a JSON response when the Controller Method is annotated with #ResponseBody.
https://stackoverflow.com/a/32071252/461055
Yes, you can write two exception handler to handle api and html request exception. Here is sample code to illustrate the solution.
#ControllerAdvice(annotations = RestController.class)
#Order(1)
class RestExceptionHandler {
#ExceptionHandler(MyException.class)
#ResponseBody
ResponseEntity<ErrorResponse> exceptionHandler() {
....
}
}
#ControllerAdvice(annotations = Controller.class)
#Order(2)
class ExceptionHandler {
#ExceptionHandler(Exception.class)
public ModelAndView handleError500(HttpServletRequest request, HttpServletResponse response, Exception ex) {
ModelAndView mav = new ModelAndView("error");
mav.addObject("error", "500");
return mav;
}
}

Does ControllerAdvice increase response time?

Is there any speed difference when using ControllerAdvice throwing RuntimeException, and when manually returning ResponseEntity to handle client errors?
1) ControllerAdvice
#RestController
public class ObjectController {
#PostMapping
public Object save(#RequestBody Object object) {
if (service.isInvalid(object))
throw new ObjectException("Client error");
return service.save(object);
}
}
public class ObjectException extends RuntimeException {
}
#ControllerAdvice
public class ObjectControllerAdvice extends ResponseEntityExceptionHandler {
#ExceptionHandler(value = {ObjectException.class})
protected ResponseEntity<Object> handleConflict(ObjectException ex, WebRequest request) {
return handleExceptionInternal(ex, ex.getLocalizedMessage(), new HttpHeaders(),
HttpStatus.BAD_REQUEST, request);
}
}
2) Manually returning ResponseEntity
#RestController
public class ObjectController {
#PostMapping
public ResponseEntity<Object> save(#RequestBody Object object) {
if (service.isInvalid(object))
return new ResponseEntity<>("Client error", HttpStatus.BAD_REQUEST);
return new ResponseEntity<Object>(service.save(object), HttpStatus.OK);
}
}
I imagine the difference is response time is negligible with the second approach possibly being very slightly faster. But the real advantage of having a #ControllerAdvice class with #ExceptionHandlers is that these can be used for multiple endpoints over multiple #Controllers and you won't have to repeat the code everywhere.
No, it's not that much different. And I think using the #ControllerAdvice is a best practice when you would like to handle your Custom Exception or to centralize the Exception to a Global class. There is a simple sample in this answer: Error page registrar and Global exception handling
Hope this help.

#RestControllerAdvice and #ControllerAdvice together

I have an Spring MVC application which has #Controller s and #RestController s.
I was thinking that: When I have some Exception at my #Controller, It gonna be handled by my #ControllerAdvice and when I have some Exception at my #RestController, It gonna be handled by my #RestControllerAdvice... But now I think It's not how things should work, because my #ControllerAdvice are catching everything, even any exception that is thrown by #RestController...I do not know if this should happen. Here my code:
#ControllerAdvice
public class ExceptionHandlerController {
private final String DEFAULT_ERROR_VIEW = "error/default";
#ExceptionHandler(Exception.class)
public ModelAndView defaultErrorHandler(HttpServletRequest req, Exception e)
{
ModelAndView mav = new ModelAndView();
mav.addObject("exception", e);
mav.addObject("danger", e.getMessage());
mav.addObject("url", req.getRequestURL());
mav.setViewName(DEFAULT_ERROR_VIEW);
return mav;
}
}
#RestControllerAdvice
public class ExceptionHandlerRestController {
#ExceptionHandler(Exception.class)
public ResponseEntity<String> defaultErrorHandler(HttpServletRequest req, Exception e) throws Exception {
return new ResponseEntity<>(" test "+e.getMessage(), HttpStatus.INTERNAL_SERVER_ERROR);
}
}
Yeah #RestControllerAdvice doesn't work that way. It's just a #ControllerAdvice with #ResponseBody automatically assumed. See #RestControllerAdvice vs #ControllerAdvice.
If you wanted one #ControllerAdvice to work with one controller and one to work with the other then if you put your controllers in separate packages you should be able to do this by doing:
#ControllerAdvice("my.controller1.package")
However, the whole point of #ControllerAdvice is to share common functionality of your separate #Controllers between each other so if you want them to do separate things you might be better off just putting the methods inside the #Controllers themselves.
If you want #RestControllerAdvice to handle only exceptions thrown from #RestController, then you can qualify it with the annotations attribute:
#RestControllerAdvice(annotations = RestController.class)
You may need #Order tag if you happen to have several other #ControllerAdvice.

Stacktrace of exceptions in Spring Rest responses

I have few Rest web services implemented through Spring. The problem is that if any exception is thrown the webservice returns json object with formatted error message that contains stacktrace. Can I have a single point of handling exceptions, and return my custom json objects with messages that wouldn't contain stacktrace?
I see descriptions for spring mvc but im not really using that for building my views etc.
I know it's too late, but just pointing out some solutions that may help others!
case 1: if you're using application.properties file, add following line to your properties file.
server.error.include-stacktrace=on_trace_param
case 2: if you're using application.yml file, add following line to your yml file.
server:
error:
include-stacktrace: on_trace_param
case 3: In case, none of them works, try following changes:
Try to suppress the stack trace by overriding fillInStackTrace method in your exception class as below.
public class DuplicateFoundException extends RuntimeException {
#Override
public synchronized Throwable fillInStackTrace() {
return this;
}
}
ps1: I referred this article.
Spring provides an out of the box solution to handle all your custom exceptions from a single point. What you need is #ControllerAdvice annotation in your exception controller:
#ControllerAdvice
public class GlobalDefaultExceptionHandler {
#ExceptionHandler(Exception.class)
public String exception(Exception e) {
return "error";
}
}
If you want to go deep into Springs #ExceptionHandler at individual controller level or #ControllerAdvice at global application level here is a good blog.
To handle exceptions thrown from a spring application at a single point, this is the best way to do it. #ControllerAdvice will create an aspect join-point which will intercept all the exceptions with required matching types bound to the corresponding public method.Here, public ResponseEntity handleDataIntegrityViolationException(DataIntegrityViolationException dataIntegrityViolationException,
WebRequest request) is handling DataIntegrityViolationException thrown out of the system at one place.
#ControllerAdvice
public class GlobalControllerExceptionHandler {
private Logger logger = Logger.getLogger(this.getClass());
private HttpHeaders header = new HttpHeaders();
#Autowired
private MessageSource messageSource;
public GlobalControllerExceptionHandler() {
header.set(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_VALUE);
}
/**
* #param dataIntegrityViolationException
* #param request
* #return
*/
#ExceptionHandler({ DataIntegrityViolationException.class })
public ResponseEntity<?> handleDataIntegrityViolationException(DataIntegrityViolationException dataIntegrityViolationException,
WebRequest request) {
String message = ExceptionUtils.getMessage(dataIntegrityViolationException);
logger.error("*********BEGIN**************DataIntegrityViolationException******************BEGIN*******************\n");
logger.error(message, dataIntegrityViolationException.fillInStackTrace());
logger.error("*********ENDS**************DataIntegrityViolationException*******************ENDS*****************************\n");
return ResponseEntity.status(HttpStatus.CONFLICT).headers(header).body(dataIntegrityViolationException);
}
}

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