HTTP 301 和 308 状态代码有什么区别？

Question

HTTP 301 和 308 状态码有什么区别？

• 301（永久移动）：此请求和所有未来请求都应定向到给定的 URI。

• 308（永久重定向）：应该使用另一个 URI 重复请求和所有未来的请求。

他们好像很像。

Answer 1

301、302 和 307

概览

不允许将请求方法从POST更改为GET的RFC 7231, the current reference for semantics and content of the HTTP/1.1 protocol, defines the 301 (Moved Permanently) and 302 (Found) status code, that allows the request method to be changed from POST to GET. This specification also defines the 307（临时重定向）状态代码。

查看下面的更多详细信息：

6.4.2. 301 Moved Permanently

The 301 (Moved Permanently) status code indicates that the target resource has been assigned a new permanent URI and any future references to this resource ought to use one of the enclosed URIs. [...]

Note: For historical reasons, a user agent MAY change the request method from POST to GET for the subsequent request. If this behavior is undesired, the 307 (Temporary Redirect) status code can be used instead.

6.4.3. 302 Found

The 302 (Found) status code indicates that the target resource resides temporarily under a different URI. Since the redirection might be altered on occasion, the client ought to continue to use the effective request URI for future requests. [...]

Note: For historical reasons, a user agent MAY change the request method from POST to GET for the subsequent request. If this behavior is undesired, the 307 (Temporary Redirect) status code can be used instead.

6.4.7. 307 Temporary Redirect

The 307 (Temporary Redirect) status code indicates that the target resource resides temporarily under a different URI and the user agent MUST NOT change the request method if it performs an automatic redirection to that URI. Since the redirection can change over time, the client ought to continue using the original effective request URI for future requests. [...]

Note: This status code is similar to 302 (Found), except that it does not allow changing the request method from POST to GET. This specification defines no equivalent counterpart for 301 (Moved Permanently) (RFC 7238, however, defines the status code 308 (Permanent Redirect) for this purpose).

需要308

RFC 7238 has been created to define the 308 (Permanent Redirect) status code, that is similar to 301（永久移动）但不允许将请求方法从 POST 更改为 GET。

308 status code is now defined by the RFC 7538 (that obsoleted the RFC 7238).

3. 308 Permanent Redirect

The 308 (Permanent Redirect) status code indicates that the target resource has been assigned a new permanent URI and any future references to this resource ought to use one of the enclosed URIs. Clients with link editing capabilities ought to automatically re-link references to the effective request URI to one or more of the new references sent by the server, where possible. [...]

Note: This status code is similar to 301 (Moved Permanently), except that it does not allow changing the request method from POST to GET.

我们有以下内容：

                                                             +-----------+-----------+
                                                             | Permanent | Temporary |
+------------------------------------------------------------+-----------+-----------+
| Allows changing the request method from POST to GET        | 301       | 302       |
+------------------------------------------------------------+-----------+-----------+
| Doesn't allow changing the request method from POST to GET | 308       | 307       |
+------------------------------------------------------------+-----------+-----------+

选择最合适的状态码

Michael Kropat put together a set of decision charts 有助于确定每种情况的最佳状态代码。请参阅以下 2xx 和 3xx 状态代码：