使用JSON和http请求获取android中的数据。获取请求无效

Question

我想在我的Android应用程序中从我的PHP代码中获取JSON结果。 如果我需要所有数据库条目，它可以很好地工作：

public class GetAllFromOnlineDatabase extends AsyncTask<String, String, String> {


    private static final String TAG = "GET_ALL";

    // URL to get all stolpersteine
    private static final String URL_ALL_STOLPERSTEINE = "http://.../get_all.php";


    // JSON node names
    private static final String TAG_SUCCESS = "success";
    private static final String TAG_STOLPERSTEINE = "stolpersteine";
    private static final String TAG_PID = "pid";
    private static final String TAG_TITLE = "title";
    private static final String TAG_FIRST_NAME = "first_name";
    private static final String TAG_LAST_NAME = "last_name";

    // Creating JSON parser object
    private JSONParser jParser = new JSONParser();

    private MapControl mapControl;

    public GetAllFromOnlineDatabase(MapControl mapControl) {
        this.mapControl = mapControl;
    }


    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected String doInBackground(String... strings) {

        // Building parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();

        // Getting JSON string from URL
        JSONObject json = jParser.makeHttpRequest(URL_ALL_STOLPERSTEINE, "GET", params);

        try {
            // Checking for success TAG in JSON
            int success = json.getInt(TAG_SUCCESS);

            if (success == 1) {

                // Getting array of products
                JSONArray memory_list_stolpersteine_table_row = json.getJSONArray(TAG_STOLPERSTEINE);

                // looping through all products
                for (int i = 0; i < memory_list_stolpersteine_table_row.length(); i++) {
                    JSONObject jsonObject = memory_list_stolpersteine_table_row.getJSONObject(i);

                    // Storing each json item in variable
                    String id = jsonObject.getString(TAG_PID);
                    String title = jsonObject.getString(TAG_TITLE);
                    String first_name = jsonObject.getString(TAG_FIRST_NAME);
                    String last_name = jsonObject.getString(TAG_LAST_NAME);
                }
            } else {
                Log.d(TAG, "Error - cannot read JSON");
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }
        return null;
    }

    protected void onPostExecute(String file_url) {
        cancel(true);
    }

}

但如果我使用另一个URL获取GET请求的详细信息，如下所示，它不起作用。 android中的json对象是空的。我怎样才能解决这个问题？感谢

private static final String URL_ALL_STOLPERSTEINE = "http://.../get_geopoint_by_id.php?pid=1";