Error 406 Not Acceptable when generating PNG response

Question

I have a problem with method generating PNG image responses.

@RequestMapping(value = "/thumb/{id}.png", produces = "image/png")
@ResponseBody
public char[] thumb(@PathVariable UUID id)
{
    // action logic here

    return CatalogController.PLACEHOLDER_THUMB;
}

However I can't access this action - it is executed correctly (I see logic effects in database), but client gets 406 Not Acceptable.

Here is how I simulate the request (same happens in Chrome and Internet Explorer):

$ wget "http://localhost:8080/thumb/13164e6b-fc0f-4c67-a7d3-e2c56224384b.png" -O - --header="Accept: image/png"
--2013-11-18 18:37:30--  http://localhost:8080/thumb/13164e6b-fc0f-4c67-a7d3-e2c56224384b.png
Resolving localhost (localhost)... ::1, 127.0.0.1
Connecting to localhost (localhost)|::1|:8080... connected.
HTTP request sent, awaiting response... 406 Not Acceptable
2013-11-18 18:37:30 ERROR 406: Not Acceptable.

Edit

Here is more detailed description displayed in browser:

description The resource identified by this request is only capable of generating responses with characteristics not acceptable according to the request "accept" headers ().

Answer 1

Ok, thanks for everyone for helping, but the answer is far more trivial - it's simply not possible to use char[] as response content.

Switched to byte[] and everything worked fine!

(probably could be possible to register handler for byte[] but it's not needed for me, so can't confirm that).