本文介绍了Content-Type仅限charset的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

我遇到了这个有趣的标题:

I came across this interesting header:

Content-Type: charset=utf-8

回答者说这个语法是由,但我不是在提供的链接中看到它的
。这是有效的语法,如果是这样,那么
具体是这个定义的吗?

The answerer says that this syntax is defined by RFC 2616, but I am notseeing it in the provided link. Is this valid syntax, and if so wherespecifically is this defined?

推荐答案

是这样的:

And the media-type production is this:

media-type     = type "/" subtype *( ";" parameter )
type           = token
subtype        = token

这表示虽然参数部分(例如 charset = utf-8 是可选的,但类型/subtype part不是 - 也就是说,媒体类型必须有一个斜杠后跟一个子类型。

That says that while the parameter part (e.g., charset=utf-8 is optional, the type "/" subtype part is not—that is, a media type must have type followed by a slash followed by a subtype.

所以 Content-Type:charset = utf-8 无效每个语法都没有特别定义,也没有在规范/权威的任何地方特别定义。

So Content-Type: charset=utf-8 isn’t valid syntax per that, and not specially defined anywhere else normatively/authoritatively to be either.

RFC 2616实际上已被RFC 7231和其他几个RFC(当前的HTTP RFC)淘汰。

RFC 2616 is actually obsoleted by RFC 7231 and several other RFCs (the current HTTP RFCs).

但是RFC 7231的相应部分为这种情况定义了基本相同的产品:

But the corresponding parts of RFC 7231 define essentially the same productions for this case:

是这样的:

The production in RFC 7231 for the value of the Content-Type header is this:

Content-Type = media-type

并且是这样的:

And the media-type production is this:

media-type = type "/" subtype *( OWS ";" OWS parameter )
type       = token
subtype    = token

没有其他规范废弃或取代该部分 - RFC 7231仍然是授权ive on this。

And no other spec obsoletes or supersedes that part—RFC 7231 remains authoritative on this.

大多数编程语言都有良好的媒体类型解析库,用于
语法检查;示例:

Most programming languages have good media-type parsing libs forsyntax checking; example:

npm install content-type
node -e "var ct = require('content-type'); ct.parse('charset=utf-8')"
=> TypeError: invalid media type
node -e "var ct = require('content-type'); ct.parse('image; charset=utf-8')"
=> TypeError: invalid media type

这篇关于Content-Type仅限charset的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!

07-30 19:08