I'm overhauling certain parts of my app to use the new GCM service to replace C2DM. I simply want to create the JSON request from a Java program for testing and then read the response. As of right now I can't find ANY formatting issues with my JSON request and the google server always return code 400, which indicates a problem with my JSON. http://developer.android.com/guide/google/gcm/gcm.html#server

JSONObject obj = new JSONObject();
    obj.put("collapse_key", "collapse key");
    JSONObject data = new JSONObject();
    data.put("info1", "info_1");
    data.put("info2", "info 2");
    data.put("info3", "info_3");
    obj.put("data", data);
    JSONArray ids = new JSONArray();
    ids.add(REG_ID);
    obj.put("registration_ids", ids);
    System.out.println(obj.toJSONString());

I print my request to the eclipse console to check it's formatting

byte[] postData = obj.toJSONString().getBytes();
    try{
    URL url = new URL("https://android.googleapis.com/gcm/send");
    HttpsURLConnection.setDefaultHostnameVerifier(new JServerHostnameVerifier());
    HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
    conn.setDoOutput(true);
    conn.setDoInput(true);
    conn.setUseCaches(false);

    conn.setRequestMethod("POST");
    conn.setRequestProperty("Content-Type", "application/json");

conn.setRequestProperty("Authorization", "key=" + API_KEY);
    System.out.println(conn.toString());
    OutputStream out = conn.getOutputStream();
              // exception thrown right here. no InputStream to get
    InputStream in = conn.getInputStream();
    byte[] response = null;
    out.write(postData);
    out.close();
    in.read(response);
    JSONParser parser = new JSONParser();
    String temp = new String(response);
    JSONObject temp1 = (JSONObject) parser.parse(temp);
    System.out.println(temp1.toJSONString());
    int responseCode = conn.getResponseCode();
     System.out.println(responseCode + "");
    } catch(Exception e){
        System.out.println("Exception thrown\n"+ e.getMessage());
    }


}

I'm sure my API key is correct as that would result in error 401, so says the google documentation. This is my first time doing JSON but it's easy to understand because of its simplicity. Anyone have any ideas on why I always receive code 400?

update: I've tested the google server example classes provided with gcm so the problem MUST be with my code.