从获取请求获取数据？

I'm sending an ajax request like so:

$.ajax({
   type: "GET",
   url:"/game/set",
   data: JSON.stringify({colour: col, size: size}),
   success: function(){console.log("SUCCESS.")},
   dataType: 'json'
});

I can receive the request on the server just fine, but I can't figure out how to pull the data from it before responding. He is how I'm handling it.

var jsonString = '';
req.setEncoding('utf8');

req.on('data', function (data) {
   jsonString += data;
});

req.on('end', function () {

   reqData = JSON.parse(jsonString);
   respond(200, JSON.stringify(reqData));

});

but I seem to get this error when trying to parse.

SyntaxError: Unexpected end of input

You can't send data in a GET request. Try POST instead.