HTTP status 406 - Please HELP!!! Spring+Ajax+JSON

[Tony Ghy]

I'm facing a problem while trying to retrieve a Collection of Object (List<MyObject>) through Ajax call using Jquery.

My jsp where i make a call is :

<script type="text/javascript">
function getCities() {
	jq(function() {
		jq.post("getCities.html",
					{ 	stateSelect:  jq("#stateSelect").val()},
						function(data){
							jq("#cities").replaceWith('<span id="cities">Changed</span>');
					});
	});
}
</script>

The getCities is mapped to the following:

@RequestMapping(value = "/getCities", method = RequestMethod.POST)
    public @ResponseBody List<StateNames> getCities(@RequestParam(value="stateSelect", required=true) String stateName,
    							Model model) {
		// Delegate to service to do the actual adding
		List<StateNames> listStates = myService.listCityNames(stateName);
		
		// @ResponseBody will automatically convert the returned value into JSON format
		// You must have Jackson in your classpath
		return listStates;
	}

I believe the problem lies here: @ResponseBody is not able to automatically convert the List value into JSON format & hence i get the following error:

406 Not Acceptable
    The requested resource is only capable of generating content not acceptable according to the Accept headers sent in the request.

Please guide me.
I used Firbug to see what's going on. Here's what i get:

Response Headers
Server	Apache-Coyote/1.1
Content-Type	text/html;charset=utf-8
Content-Length	1070
Date	Sat, 12 Feb 2011 13:09:44 GMT

Request Headers
Host	localhost:8080
User-Agent	Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.13) Gecko/20101203 Firefox/3.6.13
Accept	*/*
Accept-Language	en-us,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/x-www-form-urlencoded; charset=UTF-8
X-Requested-With	XMLHttpRequest
Referer	http://localhost:8080/MyApplication/
Content-Length	17
Cookie	JSESSIONID=640868A479C40792F8AB3DE118AF12E0
Pragma	no-cache
Cache-Control	no-cache

Please Help me. I'm stuck.

[Mark Spritzler]

That is because you are doing a POST. a POST in REST means you are creating a new object. You are not, you want to GET the List. So you have to do a GET in order for it to work.

In a POST, the accept header is not requesting any type/format back, the response should only have the success status set and the URI to then GET what just got created. So the Body of a POST is always empty.

a GET is the only RequestMethod type to return data in the Body.

an Update and a Delete only return the status.

Hope that helps

Mark