AJAX post JSON data from Javascript to Grails

I'm trying to POST JSON formatted data from Javascript (using Prototype) to Grails. My Javascript code is:

var JSONObject = new Object;
    JSONObject.id = "23";
    JSONObject.name = "Test 1";
    JSONstring = JSON.stringify(JSONObject);



 var url = "${createLink(controller:'testController', action:'receiveJson')}";
    new Ajax.Request(url, {
      method:'post',
      contentType:'application/json',
      parameters:JSONstring,
      asynchronous:true,
      onSuccess: function (req) {
        sendInfoResponse(req.responseText);
      }
    });

and the code in my Grails controller is:

def receiveJson = {
  def json = request.JSON;
}

However, the 'json' variable appears to be empty in my tests. I'd be so grateful if someone could explain开发者_Go百科 what I'm doing wrong. Many thanks.

In your Ajax.Request options change

parameters:JSONstring,

to

postBody:JSONstring,

The problem with using parameters is that it URL encodes the data so that the request body ends up looking like this:

%7B%22id%22%3A%2223%22%2C%22name%22%3A%22Test%201%22%7D&_=

Instead of the desired (which is what you get with postBody):

{"id":"23","name":"Test 1"}

Good question mfloryan - I was doing the testing manually, i.e. not as part of a unit or integration test.

Thanks very much for the help hvgotcodes. I made the changes to my code as you have suggested, but unfortunately to no avail. Interestingly, if I print request.JSON I get {}, whereas if I print request.json I get null.

EDIT: By 'printing' I mean using: request.JSON.toString()

EDIT: Thank you all so much for the help. Once I'd made the final change John Wagenleitne suggested the code began working properly. I'm very grateful indeed for all your help.

I don't think you are invoking the Ajax.Request correctly. From the documentation, the parameters option:

"The parameters for the request, which will be encoded into the URL for a 'get' method, or into the request body for the other methods. This can be provided either as a URL-encoded string or as any Hash-compatible object (basically anything), with properties representing parameters."

I think you need to do something like

...
parameters: {json: JSONString}
...

and then in your controller

request.json

note the form of the parameters object literal - it tells the Prototype library to make the request key 'json' and the request value be the json string. You access the key off the request object in the controller.

EDIT -- I just realized you're javascript block is jacked up.

This:

var JSONObject = new Object;

should be something like

var JSONObject = new Object();
...

you might also be able to do just an object literal, so

var jsonObject = {};
....