// Policy configuration file.
	bucketPolicyConfig = "policy.json"
)

// PutBucketPolicyHandler - This HTTP handler stores given bucket policy configuration as per
// https://docs.aws.amazon.com/AmazonS3/latest/dev/access-policy-language-overview.html
func (api objectAPIHandlers) PutBucketPolicyHandler(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "PutBucketPolicy")

一般情况下可能不会需要在代码中直接使用响应头。

但对于某些高级应用场景，还是需要添加自定义响应头：

{* ../../docs_src/handling_errors/tutorial002.py hl[14] *}

## 安装自定义异常处理器

添加自定义处理器，要使用 [Starlette 的异常工具](https://www.starlette.dev/exceptions/)。

假设要触发的自定义异常叫作 `UnicornException`。

且需要 FastAPI 实现全局处理该异常。

此时，可以用 `@app.exception_handler()` 添加自定义异常控制器：

{* ../../docs_src/handling_errors/tutorial003.py hl[5:7,13:18,24] *}

///

/// note | Detalles Técnicos

También podrías usar `from starlette.requests import Request`.

      val prop = Properties()
      Main::class.java.getResourceAsStream("/okcurl-version.properties")?.use {
        prop.load(it)
      }
      return prop.getProperty("version", "dev")
    }

    @Suppress("TrustAllX509TrustManager", "CustomX509TrustManager")
    private fun createInsecureTrustManager(): X509TrustManager =
      object : X509TrustManager {
        override fun checkClientTrusted(

And those two things, `scope` and `receive`, are what is needed to create a new `Request` instance.

To learn more about the `Request` check <a href="https://www.starlette.dev/requests/" class="external-link" target="_blank">Starlette's docs about Requests</a>.

///

The only thing the function returned by `GzipRequest.get_route_handler` does differently is convert the `Request` to a `GzipRequest`.

    """


class FastAPIDeprecationWarning(UserWarning):
    """
    A custom deprecation warning as DeprecationWarning is ignored
    Ref: https://sethmlarson.dev/deprecations-via-warnings-dont-work-for-python-libraries

You can achieve that using <a href="https://docs.pydantic.dev/latest/concepts/validators/#field-after-validator" class="external-link" target="_blank">Pydantic's `AfterValidator`</a> inside of `Annotated`.

/// tip

Pydantic also has <a href="https://docs.pydantic.dev/latest/concepts/validators/#field-before-validator" class="external-link" target="_blank">`BeforeValidator`</a> and others. 🤓

///

/// info | Informação

Você também pode usar:

* `response_model_exclude_defaults=True`
* `response_model_exclude_none=True`

{* ../../docs_src/sql_databases/tutorial001_an_py310.py ln[66:73] hl[71] *}

### Executar o App { #run-the-app }

Você pode executar o app:

<div class="termy">

```console
$ fastapi dev main.py

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

</div>

但是如果你想让浏览器中的客户端看到你的自定义请求头, 你需要把它们加到 CORS 配置 ([CORS (Cross-Origin Resource Sharing)](cors.md){.internal-link target=_blank}) 的 `expose_headers` 参数中,在 <a href="https://www.starlette.dev/middleware/#corsmiddleware" class="external-link" target="_blank">Starlette's CORS docs</a>文档中.

///

/// note | 技术细节

你也可以使用 `from starlette.requests import Request`.