Vous pouvez remplacer ces gestionnaires d'exception par les vôtres.

### Remplacer les exceptions de validation de la requête { #override-request-validation-exceptions }

Lorsqu'une requête contient des données invalides, **FastAPI** lève en interne une `RequestValidationError`.

Et il inclut également un gestionnaire d'exception par défaut pour cela.

    }

    @Test
    @DisplayName("Should fail validation when not received")
    void testIsValidNotReceived() {
        // When
        boolean valid = response.isValid(mockContext, mockRequest);

        // Then
        assertFalse(valid);
    }

    @Test
    @DisplayName("Should fail validation when signing enforced but not enabled")

        if (errors.isEmpty()) {
            Files.writeString(getReport().toPath(), "Success! No validation errors found.", StandardOpenOption.CREATE);
        } else {
            try (PrintWriter printWriter = new PrintWriter(getReport())) {
                printWriter.printf("Schema: %s%n", jsonSchemaOnDisk);
                printWriter.println("----------Validation Errors-----------");

        // Looks like the failure case also is just reflecting back the signature we sent

        // with SMB3's negotiation validation it's no longer possible to ignore this (on the validation response)
        // make sure that validation is performed in any case
        final Smb2SigningDigest dgst = getDigest();

)


def create_model_field(
    name: str,
    type_: Any,
    default: Any | None = Undefined,
    field_info: FieldInfo | None = None,
    alias: str | None = None,
    mode: Literal["validation", "serialization"] = "validation",
) -> ModelField:
    if annotation_is_pydantic_v1(type_):
        raise PydanticV1NotSupportedError(
            "pydantic.v1 models are no longer supported by FastAPI."

# Body - Fields { #body-fields }

The same way you can declare additional validation and metadata in *path operation function* parameters with `Query`, `Path` and `Body`, you can declare validation and metadata inside of Pydantic models using Pydantic's `Field`.

## Import `Field` { #import-field }

First, you have to import it:

{* ../../docs_src/body_fields/tutorial001_an_py310.py hl[4] *}


/// warning

                                "content": {"application/json": {"schema": {}}},
                            },
                            "422": {
                                "description": "Validation Error",
                                "content": {
                                    "application/json": {
                                        "schema": {

*   Fixes a missing validation which causes `TensorSummaryV2` to crash ([CVE-2022-29193](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-29193))
*   Fixes a missing validation which crashes `QuantizeAndDequantizeV4Grad` ([CVE-2022-29192](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-29192))

    }
    return registrySuffixIndexLocal;
  }

  /**
   * Returns an instance of {@link InternetDomainName} after lenient validation. Specifically,
   * validation against <a href="http://www.ietf.org/rfc/rfc3490.txt">RFC 3490</a>
   * ("Internationalizing Domain Names in Applications") is skipped, while validation against <a
   * href="http://www.ietf.org/rfc/rfc1035.txt">RFC 1035</a> is relaxed in the following ways:
   *
   * <ul>

            throw e;
        }
    }

    /**
     * Static method to create a synonym item from form data with validation.
     *
     * @param action the base action for validation operations
     * @param form the create form containing synonym data
     * @param hook the validation error hook for handling errors
     * @return OptionalEntity containing the created synonym item or empty if creation failed
     */