* even in the same order. (It is guaranteed to return true for instances constructed from the
   * same values in the same order if {@code strictfp} is in effect, or if the system architecture
   * guarantees {@code strictfp}-like semantics.)
   */
  @Override
  public boolean equals(@Nullable Object obj) {
    if (obj == null) {
      return false;
    }

    assertTrue(Double.isNaN(DoubleMath.log2(Double.NEGATIVE_INFINITY)));
    assertTrue(Double.isNaN(DoubleMath.log2(Double.NaN)));
  }

  @GwtIncompatible // StrictMath
  @SuppressWarnings("strictfp") // Guava still supports Java 8
  private strictfp double trueLog2(double d) {
    double trueLog2 = StrictMath.log(d) / StrictMath.log(2);
    // increment until it's >= the true value
    while (StrictMath.pow(2.0, trueLog2) < d) {

    assertTrue(Double.isNaN(DoubleMath.log2(Double.NEGATIVE_INFINITY)));
    assertTrue(Double.isNaN(DoubleMath.log2(Double.NaN)));
  }

  @GwtIncompatible // StrictMath
  @SuppressWarnings("strictfp") // Guava still supports Java 8
  private strictfp double trueLog2(double d) {
    double trueLog2 = StrictMath.log(d) / StrictMath.log(2);
    // increment until it's >= the true value
    while (StrictMath.pow(2.0, trueLog2) < d) {

   * same order. (It is guaranteed to return true for instances constructed from the same values in
   * the same order if {@code strictfp} is in effect, or if the system architecture guarantees
   * {@code strictfp}-like semantics.)
   */
  @Override
  public boolean equals(@Nullable Object obj) {
    if (obj == null) {
      return false;
    }

# Vérifier strictement le Content-Type { #strict-content-type-checking }

Par défaut, FastAPI applique une vérification stricte de l’en-tête `Content-Type` pour les corps de requêtes JSON ; cela signifie que les requêtes JSON doivent inclure un en-tête `Content-Type` valide (par ex. `application/json`) pour que le corps soit analysé comme JSON.

## Risque CSRF { #csrf-risk }

# 严格的 Content-Type 检查 { #strict-content-type-checking }

默认情况下，FastAPI 对 JSON 请求体使用严格的 `Content-Type` 头检查。这意味着，JSON 请求必须包含有效的 `Content-Type` 头（例如 `application/json`），其请求体才会被按 JSON 解析。

## CSRF 风险 { #csrf-risk }

此默认行为在一个非常特定的场景下，可防御一类跨站请求伪造（CSRF）攻击。

这类攻击利用了浏览器的一个事实：当请求满足以下条件时，浏览器允许脚本在不进行任何 CORS 预检的情况下直接发送请求：

- 没有 `Content-Type` 头（例如使用 `fetch()` 携带 `Blob` 作为 body）
- 且不发送任何认证凭据。

这种攻击主要在以下情况下相关：

- 应用在本地（如 `localhost`）或内网中运行

# Строгая проверка HTTP-заголовка Content-Type { #strict-content-type-checking }

По умолчанию **FastAPI** использует строгую проверку HTTP-заголовка `Content-Type` для JSON-тел запросов. Это означает, что JSON-запросы должны включать корректный заголовок `Content-Type` (например, `application/json`), чтобы тело запроса было обработано как JSON.

## Риск CSRF { #csrf-risk }

# Chequeo estricto de Content-Type { #strict-content-type-checking }

Por defecto, **FastAPI** usa un chequeo estricto del header `Content-Type` para request bodies JSON, esto significa que las requests JSON deben incluir un header `Content-Type` válido (p. ej. `application/json`) para que el request body se parse como JSON.

## Riesgo de CSRF { #csrf-risk }

# Strict Content-Type Checking { #strict-content-type-checking }

By default, **FastAPI** uses strict `Content-Type` header checking for JSON request bodies, this means that JSON requests **must** include a valid `Content-Type` header (e.g. `application/json`) in order for the body to be parsed as JSON.

## CSRF Risk { #csrf-risk }

This default behavior provides protection against a class of **Cross-Site Request Forgery (CSRF)** attacks in a very specific scenario.

# Sıkı Content-Type Kontrolü { #strict-content-type-checking }

Varsayılan olarak FastAPI, JSON request body'leri için sıkı Content-Type header kontrolü uygular. Bu, JSON request'lerin body'lerinin JSON olarak parse edilebilmesi için geçerli bir Content-Type header'ı (örn. application/json) içermesi gerektiği anlamına gelir.

## CSRF Riski { #csrf-risk }