谷歌距离矩阵未获取距离

我已经大致尝试从 Google Distance Matrix API ,但它没有显示距离。

我的GPS位置不是 0,0 我确信的。

字符串距离=getMatrix(纬度、经度);

我的函数代码是:

private String getMatrix(double lat , double lang){
  JSONObject jObj;
  String getdistance = "";
  String strUrl = "http://maps.googleapis.com/maps/api/distancematrix/json?origins=" 
                  + Double.toString(my_lat) + "," 
                  + Double.toString(my_lang) 
                  + "&destinations="+ Double.toString(lat) + "," 
                  + Double.toString(lang) 
                  + "&mode=walking&sensor=false";

  String data = "";
  InputStream reader = null;
  HttpURLConnection urlConnection = null;
  try{
    URL url = new URL(strUrl);
    urlConnection = (HttpURLConnection) url.openConnection();
    urlConnection.connect();

    reader = urlConnection.getInputStream();
    int bRead = -1;
    byte[] buffer = new byte[1024];
    do {
      bRead = reader.read(buffer, 0, 1024);
      if (bRead == -1) {
        break;
      }
      data += new String(buffer, 0, bRead);
    } while (true);
    urlConnection.disconnect();
  } catch(Exception e) {
  } finally {

  }

  try {
    jObj = new JSONObject(data);

    JSONArray rowsArray = jObj.getJSONArray("rows");
    JSONObject rows = rowsArray.getJSONObject(0);

    JSONArray elementsArray = rows.getJSONArray("elements");
    JSONObject newDisTimeOb = elementsArray.getJSONObject(0);

    JSONObject distOb = newDisTimeOb.getJSONObject("distance");
    getdistance = distOb.optString("text").toString();
  } catch (JSONException e) {
    e.printStackTrace();
  }

  return getdistance;
}