How can I send raw data in an HTTP GET request?

Question

In the example at http://alx3apps.appspot.com/jsonrpc_example/ when I click the submit button, I notice (by using Firebug) that my browser submits the source:

{"params":["Hello ","Python!"],"method":"concat","id":1}

It's not posting a parameter (eg. json=[encoded string from above]), but rather just posting a raw string with the above value.

Is there an widely accepted way to replicated this via a GET request, or do I need to just urlencode the same string and include it as http://www.example.com/?json=%7b%22params%22%3a%5b%22Hello+%22%2c%22Python!%22%5d%2c%22method%22%3a%22concat%22%2c%22id%22%3a1%7d? I understand that some older browsers cannot handle a URI of more than 250 characters, but I'm OK with that.

Answer 1

You are correct that only POST submits data separately from the URI. So urlencoding it into the querystring is the only way to go, if you must use GET. (Well, I suppose you could try setting custom request headers or using cookies, but the only "widely accepted" way is to use the querystring.)

Answer 2

A GET request doesn't usually transmit data in any other way besides headers, so you should pass the string encoded in the URL if you wish to use GET.

POST http://alx3apps.appspot.com/jsonrpc_example/json_service/ HTTP/1.1
Host: alx3apps.appspot.com
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-GB; rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Accept-Language: en-gb,en;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Connection: keep-alive
Content-Type: application/json-rpc; charset=UTF-8
X-Requested-With: XMLHttpRequest
Referer: http://alx3apps.appspot.com/jsonrpc_example/
Content-Length: 55
Pragma: no-cache
Cache-Control: no-cache

{"params":["Howdy","Python!"],"method":"concat","id":1}

In a normal form post the header Content-Type: application/x-www-form-urlencoded lets the server know to expect the format in key=val format whereas the page you linked sends Content-Type: application/json-rpc; charset=UTF-8. After the headers (which are terminated with the blank line) the data follows in the specified format.