POSTing JSON/XML using android-async-http (loopj)

Loopj POST examples - extended from their Twitter example:

private static AsyncHttpClient client = new AsyncHttpClient();

To post normally via RequestParams:

RequestParams params = new RequestParams();
params.put("notes", "Test api support"); 
client.post(restApiUrl, params, responseHandler);

To post JSON:

JSONObject jsonParams = new JSONObject();
jsonParams.put("notes", "Test api support");
StringEntity entity = new StringEntity(jsonParams.toString());
client.post(context, restApiUrl, entity, "application/json",
    responseHandler);

@Timothy answer did not work for me.

I defined the Content-Type of the StringEntity to make it work:

JSONObject jsonParams = new JSONObject();
jsonParams.put("notes", "Test api support");

StringEntity entity = new StringEntity(jsonParams.toString());
entity.setContentType(new BasicHeader(HTTP.CONTENT_TYPE, "application/json"));

client.post(context, restApiUrl, entity, "application/json", responseHandler);

Good Luck :)