I am new to String, SpringBoot.
Can we suppress thrown exception in a method annotated with #AfterThrowing?
I mean when an exception is thrown, it will suppress that and will return a default value on behalf of the invoking method?
Say, I have a controller -
#RestController
public class MyRestController implements IRestController{
#Override
#GetMapping("hello-throw")
public String mustThrowException(#RequestParam(value = "name")final String name) throws RuntimeException {
System.out.println("---> mustThrowException");
if("Bakasur".equals(name)) {
throw new RuntimeException("You are not welcome here!");
}
return name + " : Welcome to the club!!!";
}
}
I have created a #AspectJ, as follows -
#Aspect
#Component
public class MyAspect {
#Pointcut("execution(* com.crsardar.handson.java.springboot.controller.IRestController.*(..))")
public void executionPointcut(){
}
#AfterThrowing(pointcut="executionPointcut()",
throwing="th")
public String afterThrowing(JoinPoint joinPoint, Throwable th){
System.out.println("\n\n\tMyAspect : afterThrowing \n\n");
return "Exception handeled on behalf of you!";
}
}
If I run this & hit a ULR like - http://localhost:8080/hello-throw?name=Bakasur
I will get RuntimeException, but, I want to return a default message like - Exception handeled on behalf of you!, can we do it using #AfterThrowing?
I know it can be done using #Around, but around will be called on every hit of the url, that I do not want
What you want to do is Exception Handling on the controller. You don't need to build it yourself, Spring already supports you with some annotations like #ExceptionHandler and #ControllerAdvice. Best would be to follow this example: https://spring.io/blog/2013/11/01/exception-handling-in-spring-mvc#using-controlleradvice-classes
#ControllerAdvice
class GlobalControllerExceptionHandler {
#ResponseStatus(HttpStatus.CONFLICT) // 409
#ExceptionHandler(DataIntegrityViolationException.class)
public void handleConflict() {
// Nothing to do
}
}
#ControllerAdvice
class GlobalDefaultExceptionHandler {
public static final String DEFAULT_ERROR_VIEW = "error";
#ExceptionHandler(value = Exception.class)
public ModelAndView
defaultErrorHandler(HttpServletRequest req, Exception e) throws Exception {
// If the exception is annotated with #ResponseStatus rethrow it and let
// the framework handle it - like the OrderNotFoundException example
// at the start of this post.
// AnnotationUtils is a Spring Framework utility class.
if (AnnotationUtils.findAnnotation
(e.getClass(), ResponseStatus.class) != null)
throw e;
// Otherwise setup and send the user to a default error-view.
ModelAndView mav = new ModelAndView();
mav.addObject("exception", e);
mav.addObject("url", req.getRequestURL());
mav.setViewName(DEFAULT_ERROR_VIEW);
return mav;
}
}
You should use the fully qualified name of the class before method's name when you're referring to a pointcut. So, you should change #AfterThrowing something like this.
#AfterThrowing(pointcut="packageName.MyAspect.executionPointcut()",
throwing="th")
Please note that packageName is full package name of MyAspect.
Related
I use javax.mail dependency spring-boot-starter-mail and i want to override the error message that user get when they provide wrong email or email with domain that dose not exist. How can i override the error message of javax.mail.SendFailedException from the method getInvalidAddresses?
I want to override and pass the user a nice error message. I have my own GlobalExceptionClass which i use for all diffrent Exceptions inside my app:
#ControllerAdvice
public class GlobalExceptionHandler extends ResponseEntityExceptionHandler {
#ExceptionHandler({SendFailedException.class})
private ResponseEntity<MessageResponse> handleSendFailException(SendFailedException sfe){
if (sfe.getInvalidAddresses() != null) {
System.out.println("INVALID ADRESSS");
return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(new
MessageResponse("adress is inavlid"));
}
return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR).body(new
MessageResponse("invalidadress"));
}
}
My Controller Class
#PostMapping("/offers")
public ResponseEntity<MessageResponse> mailOffer(#Valid #RequestBody OffersDto offersDto) throws
MessagingException {
String succMessage = "success.";
offersService.addOffer(offersDto);
offersService.sendMail(offersDto);
return ResponseEntity.ok(new MessageResponse(succMessage));
}
Services class
public Offers sendMail(OffersDto offersDto) throws MessagingException {
///messaging methods, attributes
}
i just replicated this exception handling the same as for other methods, but above code dose not overrides the exception message
You have to try/catch checked exception and in catch or finally block throw new unchecked custom exception, after that handle your Custom exception(you must add attributes of MessagingException to your custom exception for checking statements)
#ExceptionHandler({CustomException.class})
I implemented feign client and hystrix to my spring boot microservice application.
I first tried to test to communicate users service to albums service with feign client,
so I threw an exception at albums service to check if users service Error Decoder can catch the exception and then make the fallback method triggered.
It worked, but the cause is always null only at the first time, and after that I can see the error message that I wanted to see.
Can anyone tell me if something is wrong or not.
This is my code.
Users Service Feign Client
#FeignClient(name = "albums-ws", fallbackFactory = AlbumsFallbackFactory.class)
public interface AlbumServiceClient {
#GetMapping(path = "users/{userId}/albums")
List<AlbumDetailResponse> getAlbums(#PathVariable("userId") String userId);
}
Fallback Factory
#Component
public class AlbumsFallbackFactory implements FallbackFactory<AlbumServiceClient> {
#Override
public AlbumServiceClient create(Throwable cause) {
return new AlbumServiceClientFallback(cause);
}
}
public class AlbumServiceClientFallback implements AlbumServiceClient {
private final Throwable cause;
private final Logger logger = LoggerFactory.getLogger(this.getClass());
public AlbumServiceClientFallback(Throwable cause) {
this.cause = cause;
}
#Override
public List<AlbumDetailResponse> getAlbums(String userId) {
logger.error("An exception took place: " + cause.getMessage());
return new ArrayList<>();
}
}
Feign Error Decoder
#Component
public class FeignErrorDecoder implements ErrorDecoder {
#Override
public Exception decode(String methodKey, Response response) {
switch(response.status()) {
case 400:
break;
case 404:
if(methodKey.contains("getAlbums")) {
return new ResponseStatusException(HttpStatus.valueOf(response.status()), response.reason());
}
break;
default:
return new Exception(response.reason());
}
return null;
}
}
First fallback triggered
2020-08-02 12:42:27.836 ERROR 24772 --- [ HystrixTimer-1] c.a.p.a.u.P.f.AlbumServiceClientFallback : An exception took place: null
After
2020-08-02 12:43:07.672 DEBUG 24772 --- [rix-albums-ws-2] c.a.p.a.u.P.feign.AlbumServiceClient : [AlbumServiceClient#getAlbums] User not found with id: f5b313e2-411f-4fc3-95e7-9aa5c43c286c
Hystrix has class org.springframework.cloud.netflix.feign.HystrixTargeter. There is a comment in targetWithFallbackFactory method:
We take a sample fallback from the fallback factory to check if it
returns a fallback that is compatible with the annotated feign
interface.
and code after:
Object exampleFallback = fallbackFactory.create(new RuntimeException());
It is why you don't have cause in exception.
I have the following RESTful Services method :
#PostMapping("/ajouterNewField")
public String ajouterField(#Valid #ModelAttribute("field") Fields field, Model model) throws IOException {
fieldDao.save(field);
// SOME CODE
return displayListeChamps( model);
}
The method is working fine and my question is how to handle any error (database not connected ...) or every issue that can happen durring the execution of this RESTful Services method.
You can use #ControllerAdvice
Refer to the code below
#ControllerAdvice
public String NyExceptionHandlerAdvice {
private final Logger logger = ...;
#ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
#ExceptionHandler({MyRunTimeException.class})
public void handleMyRunTimeException(Exception e) {
logger.error("Exception : ", e);
}
return MY_ERROR_STRING;
}
Best Practice is:
You can have your code throw RunTimeExceptions and handle all of them together or separately in handler methods similar to handleMyRunTimeException above.
You can decide what status code your request should return upon exception.
Basically you'll have to a sort of exception handler for any kind of exception your method might throw:
public class FooController{
// ...
#ExceptionHandler({ CustomException1.class, CustomException2.class })
public void handleException() {
//
}
}
Here's a nice article about that: https://www.baeldung.com/exception-handling-for-rest-with-spring
I'm able to intercept Async exceptions using the following class.
I need to register exceptions in a database,is there a way to use autowiring in this class ? It seems not to support it.
(Tried #Controller and #Service, does not work)
public class AsyncExceptionHandler implements AsyncUncaughtExceptionHandler {
#Autowired
private IDBEventService dbEventService;
#Override
public void handleUncaughtException(Throwable throwable, Method method, Object... obj) {
System.out.println("Exception message - " + throwable.getMessage());
System.out.println("Method name - " + method.getName());
for (Object param : obj) {
System.out.println("Parameter value - " + param);
}
dbEventService.recordEvent("Something happened");
}
}
A standard way to achieve what you are trying to do would be to log the exception and configure a database appender for the logger.
I'm trying to provide dynamic message for my custom Exception like in code snippet below:
#ResponseStatus(value = HttpStatus.NOT_FOUND, reason = "Entity not found")
public class EntityNotFoundException extends RuntimeException {
public EntityNotFoundException(String msg) {
super(msg);
}
}
But always when I throw it like shown below:
throw new EntityNotFoundException("User entity not found");
in the browser, I get the message "Entity not found" instead of "User entity not found".
How to achieve this?
I was stuck on this, But I just removed the reason side of the #ResponseStatus and It works, so your code should be like this:
#ResponseStatus(value = HttpStatus.NOT_FOUND)
public class EntityNotFoundException extends RuntimeException {
public EntityNotFoundException(String msg) {
super(msg);
}
}
And now you can set custom message by the constructor