You must include “Content-type: application/json” in the message header when submitting a POST request with a JSON body to my REST service via the AWS API Gateway. You will receive an error from the service if you don’t have this header.
Just what the content is encoded in is indicated in the header. In other words, you can’t always just glance at the material and know what to do with it. It is not always easy to determine the kind of the content from the content alone. The purpose of HTTP headers is to inform the recipient of the type of content they are (supposed to be) receiving.
The content is described as being in JSON format and encoded in UTF-8 character encoding by the header “Content-type: application/json”. Since UTF-8 is the default (and possibly the only?) encoding for JSON, specifying the encoding is somewhat superfluous. Because it works with or without the header, it appears that the receiving server in this instance is content with the fact that it is working with JSON and expects that the encoding is UTF-8 by default.
The number of characters that can be in the message body is actually unrestricted by encoding. The body and header can both include any content you like. However, if the two don’t line up, you might get inaccurate results. The receiver may output junk data while attempting to translate Latin1 encoded data as UTF-8 if you state in the header that the content is UTF-8 encoded but are actually delivering Latin1 encoded material. Yes, you are constrained to the 256 characters that Latin1 can encode if you explicitly state that you’re sending Latin1-encoded data and you really do so.
