# 自訂 Request 與 APIRoute 類別 { #custom-request-and-apiroute-class }

在某些情況下，你可能想要覆寫 `Request` 與 `APIRoute` 類別所使用的邏輯。

特別是，這可能是替代中介軟體（middleware）中實作邏輯的一個好方法。

例如，如果你想在應用程式處理之前讀取或操作請求本文（request body）。

/// danger

這是進階功能。

如果你剛開始使用 **FastAPI**，可以先跳過本節。

///

## 使用情境 { #use-cases }

可能的使用情境包括：

* 將非 JSON 的請求本文轉換為 JSON（例如 [`msgpack`](https://msgpack.org/index.html)）。
* 解壓縮以 gzip 壓縮的請求本文。
* 自動記錄所有請求本文。

type metacache struct {
	// do not re-arrange the struct this struct has been ordered to use less
	// space - if you do so please run https://github.com/orijtech/structslop
	// and verify if your changes are optimal.
	ended        time.Time  `msg:"end"`
	started      time.Time  `msg:"st"`
	lastHandout  time.Time  `msg:"lh"`
	lastUpdate   time.Time  `msg:"u"`
	bucket       string     `msg:"b"`

import org.opensearch.search.aggregations.bucket.missing.MissingAggregationBuilder;
import org.opensearch.search.aggregations.bucket.range.IpRangeAggregationBuilder;
import org.opensearch.search.aggregations.bucket.range.RangeAggregationBuilder;
import org.opensearch.search.aggregations.bucket.sampler.SamplerAggregationBuilder;

     * to resolve SIDs using a cache and cache the results of any SIDs that
     * required resolving with the authority. SID cache entries are currently not
     * expired because under normal circumstances SID information never changes.
     *
     * @param tc
     *            context to use
     * @param authorityServerName
     *            The hostname of the server that should be queried. For maximum efficiency this should be the hostname

			return n, VerifyError{
				Expected: r.checksum,
				Computed: etag,
			}
		}
	}
	return n, err
}

// ETag returns the ETag of all the content read
// so far. Reading more content changes the MD5
// checksum. Therefore, calling ETag multiple
// times may return different results.
func (r *Reader) ETag() ETag {
	sum := r.md5.Sum(nil)
	return ETag(sum)
}

distributed under this Agreement, and

      b) in the case of each subsequent Contributor:

         i) changes to the Program, and

         ii) additions to the Program;

where such changes and/or additions to the Program originate from and are
distributed by that particular Contributor. A Contribution 'originates' from

constraints.NotBlank.message = {item} आवश्यक है।
constraints.NotEmpty.message = {item} आवश्यक है।
constraints.ParametersScriptAssert.message = स्क्रिप्ट अभिव्यक्ति "{script}" सही नहीं है।
constraints.Range.message = {item} {min} और {max} के बीच होना चाहिए।
constraints.SafeHtml.message = {item} में असुरक्षित HTML सामग्री है।
constraints.ScriptAssert.message = स्क्रिप्ट अभिव्यक्ति "{script}" सही नहीं है।

             <b>fastapi run</b>

             Logs:

     <span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Will watch for changes in these directories:
             <b>[</b><font color="#4E9A06">&apos;/home/user/code/awesomeapp&apos;</font><b>]</b>

             <b>fastapi run</b>

             Logs:

     <span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Will watch for changes in these directories:
             <b>[</b><font color="#4E9A06">&apos;/home/user/code/awesomeapp&apos;</font><b>]</b>

constraints.NotBlank.message = {item} gereklidir.
constraints.NotEmpty.message = {item} gereklidir.
constraints.ParametersScriptAssert.message = "{script}" betik ifadesi doğru değil.
constraints.Range.message = {item}, {min} ile {max} arasında olmalıdır.
constraints.SafeHtml.message = {item} güvenli olmayan HTML içeriği içeriyor.
constraints.ScriptAssert.message = "{script}" betik ifadesi doğru değil.