Sending json as data with GET call

Question

I can see that the following curl command works remotely:

curl -X GET -d '{"begin":22, "end":33}' http://myRemoteApp.com:8080/publicApi/user/test/data

However as per the docs at http://curl.haxx.se/docs/manpage.html,

-d, --data

(HTTP) Sends the specified data in a POST request to the HTTP server, in the same way that a browser does when a user has filled in an HTML form and presses the submit button. This will cause curl to pass the data to the server using the content-type application/x-www-form-urlencoded. Compare to -F, --form.

So how is the GET working with curl if we are using -d to post data ?

Also there is no HttpUrlConnection method OR Restlet method to send json in a GET call. Is there ?

possible duplicate of [How to POST JSON data with Curl from Terminal/Commandline to Test Spring REST?](http://stackoverflow.com/questions/7172784/how-to-post-json-data-with-curl-from-terminal-commandline-to-test-spring-rest) — Gaurav Dave, Apr 28 '15 at 16:53
It's an unusual HTTP request, but some servers accept it apparently. — James Kingsbery, Apr 28 '15 at 18:20
Yes, Restlet doesn't support payload for GET methods in its client API... — Thierry Templier, Apr 29 '15 at 10:06

score 3 · Accepted Answer · edited May 23 '17 at 11:58

According to the curl documentation, -X forces the method word to be a particular value, regardless of whether it results in a sensible request or not. We can run curl with tracing to see what it actually sends in this case:

$ curl -X GET -d '{"begin":22, "end":33}' --trace-ascii - http://localhost:8080/
== Info: About to connect() to localhost port 8080 (#0)
== Info:   Trying ::1... == Info: connected
== Info: Connected to localhost (::1) port 8080 (#0)
=> Send header, 238 bytes (0xee)
0000: GET / HTTP/1.1
0010: User-Agent: curl/7.19.7 (x86_64-redhat-linux-gnu) libcurl/7.19.7
0050:  NSS/3.14.3.0 zlib/1.2.3 libidn/1.18 libssh2/1.4.2
0084: Host: localhost:8080
009a: Accept: */*
00a7: Content-Length: 22
00bb: Content-Type: application/x-www-form-urlencoded
00ec:
=> Send data, 22 bytes (0x16)
0000: {"begin":22, "end":33}

So this command does in fact cause curl to send a GET request with a message body.

This question has some extensive discussion of using GET with a request body. The answers agree that it's not actually illegal to send a GET request with a message body, but you can't expect the server to pay attention to the body. It seems that the specific server which you're using does handle these requests, whether due to a bug, happy accident, or deliberate design decision.

GET with a request-body is a perfectly valid HTTP request. Just unusual. — Daniel Stenberg, Apr 28 '15 at 19:04

Sending json as data with GET call

1 Answers1