问题
When sending a HTTP Response, should I conclude the response body (the content itself) with a newline (line separator)?
And if so, should I include the size of the line separator (I guess increase the count with 2 if sending \r\n) in the Content-Length?
回答1:
When sending a HTTP Response, should I conclude the response body (the content itself) with a newline (line separator)? And if so, should I include the size of the line separator (I guess increase the count with 2 if sending \r\n) in the Content-Length?
NO!
The resource data that is being sent in the HTTP response's message-body may include its own newlines (as is common in text files, etc), but that is arbitrary data as far as HTTP itself is concerned. Newlines inside the message-data are NOT part of the HTTP response itself. The HTTP response is terminated by reaching the Content-Length (which is the byte size of the resource data) unless Transfer-Encoding is used (in which case Content-Length is ignored, and the chunked encoding is used, which is self-terminating), or the connection is closed at the end of the response. This is described in RFC 2616 Section 4.4:
4.4 Message Length
The transfer-length of a message is the length of the message-body as
it appears in the message; that is, after any transfer-codings have
been applied. When a message-body is included with a message, the
transfer-length of that body is determined by one of the following
(in order of precedence):
1.Any response message which "MUST NOT" include a message-body (such
as the 1xx, 204, and 304 responses and any response to a HEAD
request) is always terminated by the first empty line after the
header fields, regardless of the entity-header fields present in
the message.
2.If a Transfer-Encoding header field (section 14.41) is present and
has any value other than "identity", then the transfer-length is
defined by use of the "chunked" transfer-coding (section 3.6),
unless the message is terminated by closing the connection.
3.If a Content-Length header field (section 14.13) is present, its
decimal value in OCTETs represents both the entity-length and the
transfer-length. The Content-Length header field MUST NOT be sent
if these two lengths are different (i.e., if a Transfer-Encoding
header field is present). If a message is received with both a
Transfer-Encoding header field and a Content-Length header field,
the latter MUST be ignored.
4.If the message uses the media type "multipart/byteranges", and the
transfer-length is not otherwise specified, then this self-
delimiting media type defines the transfer-length. This media type
MUST NOT be used unless the sender knows that the recipient can parse
it; the presence in a request of a Range header with multiple byte-
range specifiers from a 1.1 client implies that the client can parse
multipart/byteranges responses.
A range header might be forwarded by a 1.0 proxy that does not
understand multipart/byteranges; in this case the server MUST
delimit the message using methods defined in items 1,3 or 5 of
this section.
5.By the server closing the connection. (Closing the connection
cannot be used to indicate the end of a request body, since that
would leave no possibility for the server to send back a response.)
For compatibility with HTTP/1.0 applications, HTTP/1.1 requests
containing a message-body MUST include a valid Content-Length header
field unless the server is known to be HTTP/1.1 compliant. If a
request contains a message-body and a Content-Length is not given,
the server SHOULD respond with 400 (bad request) if it cannot
determine the length of the message, or with 411 (length required) if
it wishes to insist on receiving a valid Content-Length.
All HTTP/1.1 applications that receive entities MUST accept the
"chunked" transfer-coding (section 3.6), thus allowing this mechanism
to be used for messages when the message length cannot be determined
in advance.
Messages MUST NOT include both a Content-Length header field and a
non-identity transfer-coding. If the message does include a non-
identity transfer-coding, the Content-Length MUST be ignored.
When a Content-Length is given in a message where a message-body is
allowed, its field value MUST exactly match the number of OCTETs in
the message-body. HTTP/1.1 user agents MUST notify the user when an
invalid length is received and detected.
回答2:
I don't see anything like this in RFC 2616:
Response = Status-Line ; Section 6.1
*(( general-header ; Section 4.5
| response-header ; Section 6.2
| entity-header ) CRLF) ; Section 7.1
CRLF
[ message-body ] ; Section 7.2
There are two newlines in a response, both are at the end of the headers, not at the end of the message-body. The headers will describe how the message-body is terminated.
回答3:
When sending a HTTP Response, should I conclude the response body (the content itself) with a newline (line separator)?
The RFC doesn't require you to send a newline. The message length is not calculated based on the presence of such a newline. See Message Length section which describes how the message length is calculated.
来源：https://stackoverflow.com/questions/13821263/should-newline-be-included-in-http-response-content-length