错误org.json.JSONException：发布用户ID时字符0处的输入结束

Question

我是Android新手。 我只想通过用户ID从我的数据库中获取广告，但得到的错误如： org.json.JSONException: End of input at character 0 of 。 没有发布用户ID，只获得数据库中的所有广告工作正常。

private void loadProducts(final String user_id) {

    StringRequest stringRequest = new StringRequest(Request.Method.GET, 
                                 AppConfig.URL_USER_ADVERTISEMENT_LIST,
        new Response.Listener<String>() {
            @Override
            public void onResponse(String response) {
                try {
                    // Converting the string to json array object.
                    Log.i("tagconvertstr", "["+response+"]");
                    JSONArray array = new JSONArray(response);

                    // Traversing through all the object.
                    for (int i = 0; i < array.length(); i++) {

                        // Getting advertisement object from json array.
                        JSONObject advertisement = 
                        array.getJSONObject(i);

                        // Adding the user advertisement to user adv list
                        UserAdvertisementList.add(
                        new UserAdvertisementListObject(
                                advertisement.getString("uid"),
                                advertisement.getString("name"),
                                advertisement.getString("datetime"),
                                advertisement.getString("from_city"),
                                advertisement.getString("to_city"),
                                advertisement.getString("car_name"),
                                advertisement.getInt("car_make_year"),
                                advertisement.getInt("phone"),
                                advertisement.getInt("number_of_places"),
                                advertisement.getDouble("price")
                        ));
                    }

                    // Creating adapter object and setting it to recycler
                    // view
                    UserAdvertisementListAdapter adapter = new 
                    UserAdvertisementListAdapter(
                    UserAdvertisementListActivity.this.getActivity(), 
                    UserAdvertisementList);
                    recyclerView.setAdapter(adapter);
                } catch (JSONException e) {
                    e.printStackTrace();
                }
            }
        },
        new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Log.e(TAG, "Advertisement List Error: " + 
                error.getMessage());
                Toast.makeText(getActivity().getApplicationContext(),
                        error.getMessage(), Toast.LENGTH_LONG).show();
                hideDialog();
            }
        }) {

        @Override
        protected Map<String, String> getParams() {
            // Posting params to advertisement list url.
            Map<String, String> params = new HashMap<String, String>();
            params.put("user_id", user_id);

            return params;
        }
    };

    // Adding our string request to queue.
    Volley.newRequestQueue(
    UserAdvertisementListActivity.this.getActivity()).add(stringRequest);
}

这是我的php文件，我想获取user_id ，然后通过此user_id获取所有数据：

if (isset($_POST['user_id'])){

$user_id = $_POST['user_id'];

$stmt = $conn->prepare("SELECT unique_id, name, phone, from_city, to_city, car_name, car_make_year, number_of_places, price, datetime 
                         FROM users 
                         INNER JOIN advertisement ON users.unique_id = advertisement.user_id
                         WHERE users.unique_id = ?");

$stmt->bind_param("s", $user_id);
$stmt->execute();
$stmt->bind_result($user_id, $name, $phone, $from_city, $to_city, $car_name, $car_make_year, $number_of_places, $price, $datetime);

$products = array();

while($stmt->fetch())
{
    $temp = array();
    $temp['uid'] = $user_id;
    $temp['name'] = $name;
    $temp['phone'] = $phone;
    $temp['from_city'] = $from_city;
    $temp['to_city'] = $to_city;
    $temp['car_name'] = $car_name;
    $temp['car_make_year'] = $car_make_year;
    $temp['number_of_places'] = $number_of_places;
    $temp['price'] = $price;
    $temp['datetime'] = $datetime;

    array_push($products, $temp);
}
echo json_encode($products);
}

错误：

W/System.err: org.json.JSONException: Value {"error":false} of type 
org.json.JSONObject cannot be converted to JSONArray
W/System.err:     at org.json.JSON.typeMismatch(JSON.java:111)
    at org.json.JSONArray.<init>(JSONArray.java:96)
    at org.json.JSONArray.<init>(JSONArray.java:108)
    at com.vladimirspucko.organizer.activity.UserAdvertisementListActivity$1.onResponse(UserAdvertisementListActivity.java:108)
    at com.vladimirspucko.organizer.activity.UserAdvertisementListActivity$1.onResponse(UserAdvertisementListActivity.java:102)
    at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:60)
    at com.android.volley.toolbox.StringRequest.deliverResponse(StringRequest.java:30)
    at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(ExecutorDelivery.java:99)
    at android.os.Handler.handleCallback(Handler.java:754)
    at android.os.Handler.dispatchMessage(Handler.java:95)
    at android.os.Looper.loop(Looper.java:163)
    at android.app.ActivityThread.main(ActivityThread.java:6393)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:933)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:823)

Answer 1

将Request.Method.GET更改为Request.Method.POST并解决了我的问题。