Spring.Rest - how to post with url encoding instead of multi-part

[bryantg]

I am trying to do a PostForMessageAsync with either a dictionary or newtonsoft json object (though I don't really care what I use) of values to a server, and send them URLENCODED (C# Winforms, btw). First, the default behavior is multipart, so I can't just take the easy path, and call the post with a url and a dictionary, I have to start building HttpHeaders and HttpEntities. The first problem is the docs refer to HttpEntity as a typed class, i.e. HttpEntity<T>, which it is not. Oh, but perhaps that's because the only docs on the class are for Java. But I digress . . .

To start, I create a rest template and add several format converters, including NJsonHttpMessageConverter. In my server call function, I can do the following:

var headers = new HttpHeaders();
headers.ContentType = MediaType.APPLICATION_FORM_URLENCODED;

IDictionary<string, object> parts = new Dictionary<string, object>();
parts.Add("token", loginToken);
parts.Add("service_type", string.Format("{0}", (int)shareType));
parts.Add("message", message);
var entity = new HttpEntity(parts, headers);
restTemplate.PostForMessageAsync(url, entity, r => {
                    // snip, check r.Error
                });

This call works, but it does not send it urlencoded as requested, it sends it in multi-part mime, which the server throws up on.

So I also tried the following (same header)

var json = new JObject();
json.Add("token", loginToken);
json.Add("service_type", string.Format("{0}", (int)shareType));
json.Add("message", message);
var entity = new HttpEntity(parts, headers);
restTemplate.PostForMessageAsync(url, entity, r => {
                    // snip, check r.Error
                });

This call fails, with the dreaded "no converter available" (actual error text: "Could not write request: no suitable IHttpMessageConverter found for request type [Newtonsoft.Json.Linq.JObject] and content type [application/x-www-form-urlencoded]"). What? I guess that's better than just ignoring the content type when it's a dictionary. For kicks and giggles, I tried a third round, changing the MediaType in the header to APPLICATION_JSON. It also worked, but of course, the server had no clue how to handle straight up json.

What's the path to get my data to the server in a URLENCODED format? Spring claims to make REST easy . . .

Thanks,
Greg