spring boot对无效请求的自定义错误响应

Question

我有一个实现REST API的spring boot应用程序。我有一个POSTendpoint，它通过@requestbody接收一个对象，这个对象有几个字段，其中一些字段的类型为long。我面临的问题是，当我接收到一个包含字母字符串作为long类型字段值的无效请求有效负载时，应用程序返回一个带有空有效负载的HTTP 400响应，但我希望能够自定义该响应（例如通过@controlleradvice)并提供一些错误描述。然而，直到现在我都没能做到。

请求有效负载对象：

public final class ExchangeRateDTO {
    public final Long provider;
    public final String from;
    public final String to;
    public final BigDecimal amount;
    public final String date;

    public ExchangeRateDTO(Long provider, String from, String to, BigDecimal amount, String date) {
        this.provider = provider;
        this.from = from;
        this.to = to;
        this.amount = amount;
        this.date = date;
    }
}

控制器：

@RestController
@RequestMapping("/v1/exchangerate")
public class ExchangeRateController {
    private CommandBus commandBus;

    @Autowired
    public ExchangeRateController(CommandBus commandBus) {
        this.commandBus = commandBus;
    }

    @PostMapping
    @ResponseStatus(HttpStatus.CREATED)
    @Loggable(operationName="AddExchangeRateRequest")
    public void create(@RequestBody ExchangeRateDTO exchangeRate) {
        commandBus.dispatch(new AddExchangeRateCommand(exchangeRate.provider, exchangeRate.from, exchangeRate.to, exchangeRate.amount, exchangeRate.date));
    }
}

ControllerAdvice类：

@RestControllerAdvice
public class ExchangeRateStoreExceptionHandler extends ResponseEntityExceptionHandler {
    private ErrorResponseAdapter errorResponseAdapter;
    private ErrorStatusAdapter errorStatusAdapter;

    public ExchangeRateStoreExceptionHandler() {
        this.errorResponseAdapter = new ErrorResponseAdapter();
        this.errorStatusAdapter = new ErrorStatusAdapter();
    }

    @ExceptionHandler({ValidationError.class})
    protected ResponseEntity<ValidationErrorResponse> handleValidationError(ValidationError error) {
        ValidationErrorResponse errorResponse = errorResponseAdapter.fromValidationError(error);
        return new ResponseEntity<>(errorResponse, HttpStatus.BAD_REQUEST);
    }

    @ExceptionHandler({DomainError.class})
    protected ResponseEntity<ErrorResponse> handleDomainError(DomainError error) {
        ErrorResponse errorResponse = errorResponseAdapter.fromDomainError(error);
        HttpStatus errorStatus = errorStatusAdapter.fromDomainError(error);
        return new ResponseEntity<>(errorResponse, errorStatus);
    }

    @ExceptionHandler({Exception.class})
    protected ResponseEntity<ErrorResponse> handleAllOtherExceptions(Exception exception) {
        String message = "There was an unexpected error. Please retry later.";
        ErrorResponse errorResponse = new ErrorResponse(INTERNAL.toString(), message);
        return new ResponseEntity<>(errorResponse, HttpStatus.INTERNAL_SERVER_ERROR);
    }
}

示例请求：

curl -vX POST http://localhost:8081/v1/exchangerate \
  -H 'Content-Type: application/json' \
  -d '{
    "provider": 1,
    "from": "USD",
    "to": "EUR",
    "amount": "as",
    "date": "2018-11-22T00:00:00Z"
}'

及其回应：

< HTTP/1.1 400
< Content-Length: 0
< Date: Mon, 11 Mar 2019 16:53:40 GMT
< Connection: close

知道吗？

Answer 1

您已经扩展了ResponseEntityExceptionHandler，所以您所需要的只是@overridehandleHttpMessageNotReadable方法：

@ControllerAdvice
public class ExchangeRateStoreExceptionHandler extends ResponseEntityExceptionHandler {

    @Override
    protected ResponseEntity<Object> handleHttpMessageNotReadable(HttpMessageNotReadableException ex, HttpHeaders headers, HttpStatus status, WebRequest request) {
        return new ResponseEntity<>(ex.getLocalizedMessage(), status);
    }

}