如何在 SpringBoot REST Api 中调用重写的 handleMethodArgumentNotValid？

Question

I am struggling to invoke the overridden MethodArgumentNotValidException in my spring boot REST api. My other exception handlers work like a charm, however overriding the standard handleMethodArgumentNotValid is never getting triggered?

Anyone got a clue what I missed?

Pojo

public class FundsConfirmationRequest {
  @NotNull(message = "Required Parameter: Account Identifier.")
  private String accountId;
  @NotNull(message = "Required Parameter: Transaction Amount.")
  @Digits(integer=12, fraction=5, message = "Fractions limited to 5 digits.")
  private BigDecimal amount;
  @NotNull(message = "Required Paramater: Currency Code.")
  @Size(min = 3, max = 3, message = "Use ISO4217 Currency Code standard.")
  private String ccy;
  private String cardNumber;
  private String payee;

   public FundsConfirmationRequest() { } 
}

Controller-Method:

@RestController("fundsConfirmationController")
@RequestMapping(
        value="/accounts/{accountId}/funds-confirmations"
)
public class FundsConfirmationController implements FundsConfirmationControllerI {

    @GetMapping(
            headers = {"X-CAF-MSGID", "X-AccessToken"},
            consumes = MediaType.APPLICATION_JSON_VALUE,
            produces = MediaType.APPLICATION_JSON_VALUE
    )
    public ResponseEntity<?> fundsConfirmation(@RequestHeader(value="X-CAF-MSGID") String messageId,
                                               @RequestHeader(value="X-AccessToken") String accessToken,
                                               @Valid FundsConfirmationRequest requestParams) throws FIClientException, FIParseException {

Exception handler via @RestControllerAdvice

@RestControllerAdvice
public class FundsConfirmationExceptionHandler extends ResponseEntityExceptionHandler {

    //Existing Exception Handlers
    @Override
    public ResponseEntity<Object> handleMethodArgumentNotValid(MethodArgumentNotValidException ex, HttpHeaders headers, HttpStatus status, WebRequest request) {
        System.out.println("Custom handleMethodArgumentNotValid method");
        FundsConfirmationError responseBody = new FundsConfirmationError(HttpStatus.BAD_REQUEST.toString(), "Input Validation Failed. Parameter.: " + ex.getParameter().getParameterName() + " Value.: " + ex.getParameter().getParameter().toString() + " " + ex.getMessage(), Severity.ERROR.toString(), Sources.LOCAL_CAF_API.toString() );
        return ResponseEntity
                .status(HttpStatus.BAD_REQUEST)
                .header("X-CAF-ResponseID", request.getHeader("X-CAF-MSGID"))
                .body(responseBody);
    }

Answer 1

Apparently this is happening due to some Spring 'magic'. This is touching various concepts I was not very familiar with because the framework 'hides' this complexity away.

In my example I have a 'GET' request for which I map the pathParams/requestParams to a complex object. As an extra I want to do validation on these Params.

However due to how 'data binding to complex objects' works in Spring there is no annotation required. As a result this is 'Data Binding' and not 'Method Mapping'. The resulting exception being triggered by this specific case is not MethodArgumentNotValid but it is a BindException.

How exactly Spring maps data to objects in a REST call is dependent on various things like ContentType, Annotations Used, ...

Answer 2

I think you need to add @Order(Ordered.HIGHEST_PRECEDENCE) annotation with @ControllerAdvice

@Order(Ordered.HIGHEST_PRECEDENCE)
@RestControllerAdvice
public class FundsConfirmationExceptionHandler extends ResponseEntityExceptionHandler