Get Content Type of Request

问题

To find the incoming content type, docs say:

 request.headers["Content-Type"] # => "text/plain"

But I found by trial-and-error, that doesn't work, but this does:

 request.headers["CONTENT_TYPE"]=='application/json'

So what's the most robust+portable way to do it?

回答1:

I would usually go for request.format and request.content_type for reading these header fields.

EDIT: found a bit more on this that might help: https://stackoverflow.com/a/1595453/624590

回答2:

You don't need to parse the content_type string, Rails has already done this for you. Just check:

request.format.symbol == :json

回答3:

Another way of writing it:

request.format.json?

回答4:

No need to call #symbol since equals is overloaded:

request.format == :json

回答5:

request.format == 'application/json'

回答6:

For me the best way to check if incoming request is a json was:

    if request.content_type =~ /json/

来源：https://stackoverflow.com/questions/15227145/get-content-type-of-request