I am using Spring Boot to handle REST calls. In this context, I have implemented a controller class with the following method:

@GetMapping("/{id}")
public ResponseEntity<employeeDetails> getEmployee(@PathVariable Long id) {
    Optional<Employee> employee = employeeService.getEmployee(id);
    if (employee.isPresent()) {
        return ResponseEntity.ok(employee.get());
    } else {
        throw new ApiRequestException("Could not find requested employee");
    }
}

I am now sending a request, asking for a non-existent employee. I have verified that the else-block is executed. My issue is that I am not returned a custom error message, instead I see the same old error message in my Browser console that I have seen before implementing the ApiRequestException:

I cannot understand why I don't see my custom error message. Here is how I have implemented the ApiRequestException:

1. I have implemented the ApiRequestException class:

   public class ApiRequestException extends RuntimeException {
   
     public ApiRequestException(String message) {
       super(message);
     }
   }
   

2. I have implemented an Exception handler:

   @ControllerAdvice
   public class ApiExceptionHandler {
   
     @ExceptionHandler(value = { ApiRequestException.class })
     public ResponseEntity<Object> handleApiRequestException(ApiRequestException e) {
       HttpStatus badRequestStatus = HttpStatus.BAD_REQUEST;
       ApiRequestError apiRequestError = new ApiRequestError(badRequestStatus, e.getMessage());
       return ResponseEntity.status(badRequestStatus)
                            .body(apiRequestError);
     }
       }
   

3. Well, as you can see, the exception handler is using an ApiRequestError class. I have implemented this as well: It's just a class that stores a message-string and an httpStatus.

When debugging my application, I have verified that the exception handler is called. Setting a breakpoint inside my GET-Controller shows that the ApiRequestException is thrown. The exception is handled by the ExceptionHandler. But the return statement of this method does not get me straight back to my controller, which is what I would have thought, but instead the doInvoke-method inside InvocableHandlerMethod class is called and the following line is being executed:

return KotlinDetector.isSuspendingFunction(method) ? CoroutinesUtils.invokeSuspendingFunction(method, this.getBean(), args) : method.invoke(this.getBean(), args);

This seems a bit weird to me - why is there even a KotlinDetector, what does my Java code have to do with Kotlin?

So, anyways, I cannot explain why there is no custom error message in my browser console, but instead what seems to be a default message generated by Spring Boot. Can somebody help?

CodePudding user response：

Try extending ResponseEntityExceptionHandler

@ControllerAdvice
public class ApiExceptionHandler extends ResponseEntityExceptionHandler{
    ...
}

CodePudding user response：

Did you add these configs in the properties file?

server.error.include-message=always
server.error.include-binding-errors=always