rest - 是否仍然有 HTTP 301 而不是 HTTP 308 的用例来指示资源已移动(特别是在 ReST 服务器中)？

Question

我正在指定一个 ReST 服务。我最近偶然发现了这个 IETF draft document这可以解释为建议 ReST 服务应始终返回 308。请注意，该文档似乎已过期而未被取代(我对 IETF 流程不是很清楚)。

我早些时候想到，服务应该为 GET 返回“301 Moved Permanently”，为 POST 返回“308 Permanent Redirect”，以确保它不会不恰本地转换为 GET(通过某些试图变得聪明的东西).

301 和 308 的使用似乎是用“应该”和“不应该”来表达的，而不是“必须”和“不能”，因此从哲学上讲，“正确的事情”是什么还不清楚。

GET 的 301 和 POST 的 308 应该有效。 GET 的 308 没有错误，因为 current revision在撰写本文时，包含响应 GET 生成 308 的示例。 现在有一个部署问题，如果客户端不理解 308，它应该将其视为 300(而不是 301，这对我来说更有意义)，但 308 现在已被广泛理解，所以问题变成了你是否或为什么应该使用 HTTP 301？

如果 308 本质上是 301 的错误修复，为什么 301 没有在 HTTP/1.1 中正式弃用？是否存在将 POST 转换为 GET 以在 ReST 或更普遍的 HTTP 中重定向的合法用例？

对于 301 HTTP/1.1 说:

Note: For historical reasons, a user agent MAY change the request method from POST to GET for the subsequent request.

为什么这是个好主意？它在任何地方仍然有效吗？

另见:

• What's the difference between HTTP 301 and 308 status codes? 它很好地涵盖了 301 和 308 之间的差异，但没有涵盖这一点。
• How should client of Restful API handle http status 301 redirect upon POST?
• What's the deal with HTTP status code 308?

Answer 1

If 308 is essentially a bug fix for 301, why isn't 301 officially deprecated in HTTP/1.1?

不，不是。

RFC 7538 ，它定义了 308 状态代码，不会使 301 失效或过时。它只是定义另一个 状态代码来填补 RFC 7231 上的空白，它没有定义永久 状态码 307 的变体:

+-------------------------------------------+-----------+-----------+
|                                           | Permanent | Temporary |
+-------------------------------------------+-----------+-----------+
| Allows changing the request method from   | 301       | 302       |
| POST to GET                               |           |           |
| Does not allow changing the request       | -         | 307       |
| method from POST to GET                   |           |           |
+-------------------------------------------+-----------+-----------+

实际上，我仍然看到 301 主要用于 SEO。我还看到一些 HTTP 客户端无法识别 308。

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除了RFC，让我们看看Mozilla 的MDN Web 文档say关于301:

The HyperText Transfer Protocol (HTTP) 301 Moved Permanently redirect status response code indicates that the resource requested has been definitively moved to the URL given by the Location headers. A browser redirects to this page and search engines update their links to the resource (in 'SEO-speak', it is said that the 'link-juice' is sent to the new URL).

Even if the specification requires the method (and the body) not to be altered when the redirection is performed, not all user-agents align with it - you can still find this type of bugged software out there. It is therefore recommended to use the 301 code only as a response for GET or HEAD methods and to use the 308 Permanent Redirect for POST methods instead, as the method change is explicitly prohibited with this status.

现在看看Mozilla says关于308:

The HyperText Transfer Protocol (HTTP) 308 Permanent Redirect redirect status response code indicates that the resource requested has been definitively moved to the URL given by the Location headers. A browser redirects to this page and search engines update their links to the resource (in 'SEO-speak', it is said that the 'link-juice' is sent to the new URL).

The request method and the body will not be altered, whereas 301 may incorrectly sometimes be changed to a GET method.

^{Note: Some Web applications may use the 308 Permanent Redirect in a non-standard way and for other purposes. For example, Google Drive uses a 308 Resume Incomplete response to indicate to the client when an incomplete upload stalled. (reference)}