问题
Is there any way to know if the message body of an HTTP response is encoded with Base64?
I learnt that content-transfer-encoding is not part of HTTP header.
So, which HTTP header indicates that the content is encoded with Base64? I think Content-encoding is only used for compressions.
回答1:
As far as I understand, an HTTP body may not be encoded in Base64:
HTTP does not use the Content-Transfer-Encoding (CTE) field of RFC 2045. Proxies and gateways from MIME-compliant protocols to HTTP MUST remove any non-identity CTE ("quoted-printable" or "base64") encoding prior to delivering the response message to an HTTP client.
Identity being:
The default (identity) encoding; the use of no transformation whatsoever.
Of course you're allowed to transport Base64-encoded data using HTTP, but that should be something both parties (client and server) agree on, and there doesn't seem to be a header to describe this behavior.
来源：https://stackoverflow.com/questions/13265902/http-content-encoding-base64