HttpURLConnection객체로 JSONOjbect를 Post방식으로 

PHP로 넘겼는데 도무지 넘어 오지않네요...

===============================================================================안드로이드 소스코드

JSONObject result = null;

try{
    URL urlCon = new URL(strUrl);
    HttpURLConnection httpCon = (HttpURLConnection) urlCon.openConnection();

    String json = post.toString();

    httpCon.setRequestProperty("Accept", "application/json");
    httpCon.setRequestProperty("Content-type", "application/json");
    httpCon.setRequestProperty("Content-type","application/x-www-form-urlencoded");

    httpCon.setDoOutput(true);
    httpCon.setDoInput(true);
    httpCon.setUseCaches(false);
    httpCon.setDefaultUseCaches(false);

    OutputStream os = httpCon.getOutputStream();
    os.write(json.getBytes("utf-8"));
    os.flush(); // 여기까지 JSONObject 값을 넘기는데 PHP $_POST에 아무것도 들어 있지 않아요

    InputStream is = httpCon.getInputStream();
    BufferedReader reader = new BufferedReader(new InputStreamReader(is));

    String line;
    StringBuilder strResult = new StringBuilder();
while ((line = reader.readLine()) != null)
        strResult.append(line);

    httpCon.disconnect();
    result = new JSONObject(strResult.toString());
} catch (UnsupportedEncodingException e)
{
    e.printStackTrace();
} catch (IOException e)
{
    e.printStackTrace();
} catch (JSONException e)
{
    e.printStackTrace();
}

============================================PHP 소스코드