Android Studio - 从 Google Places 详细信息 API 解析 JSON

Question

Bit of a strange issue here. Currently I have an activity which gets the names and place ids of all the taxi companies using Google Places Search API and places them into a list view. Then when the item is clicked it will take the place id and run the Places Details API to fetch the phone number.

Currently I am running into the issue where the first time the item is clicked in the list view the JSON parser will return a NULL and the phone will dial a number like 6855 or 685-5. If you go back and click on the same item or another item then the phone number will fetch correctly.

In the activity I am running 2 JSON parsers however they run at different times.

onCreate:

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_taxi);
    mQueue = Volley.newRequestQueue(this);
    pQueue = Volley.newRequestQueue(this);
    listItem = new ArrayList<>();
    placeid = new ArrayList<>();
    police = findViewById(R.id.textView11);
    userlist = findViewById(R.id.users_list);
    jsonParse();
    userlist.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            String phone = jsonParseNumber(position);
            }
        });
    }

jsonParse (Gets the names of the taxi companies locally)

        private void jsonParse() {
        String url = "https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=51.6232817,0.2919483&radius=1000&type=taxi%20service&keyword=taxi&key=APIKEY";
    JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
        @Override
        public void onResponse(JSONObject response) {
            try {
                JSONArray jsonArray = response.getJSONArray("results");
                for (int i = 0; i < jsonArray.length(); i++){
                    JSONObject result = jsonArray.getJSONObject(i);
                    String name = result.getString("name");
                    String id = result.getString("place_id");
                    placeid.add(id);
                    listItem.add(name);
                }
                adapter = new ArrayAdapter(Taxi.this, R.layout.row, listItem);
                userlist.setAdapter(adapter);
            } catch (JSONException e) {
                e.printStackTrace();
            }

        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            error.printStackTrace();
        }
    });

    mQueue.add(request);
}

jsonParseNumber (gets the number and calls it - This is the code which is returning NULL when it is first ran)

private String jsonParseNumber(int pos) {
    String id = placeid.get(pos);
    String url = "https://maps.googleapis.com/maps/api/place/details/json?placeid="+id+"&key=APIKEY";
    JsonObjectRequest request = new JsonObjectRequest(Request.Method.GET, url, null, new Response.Listener<JSONObject>() {
        @Override
        public void onResponse(JSONObject response) {
            try {
                JSONObject jsonArray = response.getJSONObject("result");
                for (int i = 0; i < jsonArray.length(); i++){
                    number = jsonArray.getString("formatted_phone_number");
                }
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            error.printStackTrace();
        }
    });

    pQueue.add(request);
    Intent intent = new Intent(Intent.ACTION_DIAL);
    intent.setData(Uri.parse("tel: " + number));
    startActivity(intent);
    return number;

}

At first I thought it could be that the Dial Action is being called before the Parser finished so I moved it to the end of jsonParseNumber to make sure but it still does the same.

Quick notes:

2 JSON Parsers in Activity

1st Parser gets JSON from GOOGLE PLACES SEARCH API to get names and place id of taxi companies in the area

2nd Parser uses the place id to get a JSON from GOOGLE PLACES DETAILS to get the phone number

When the 2nd Parser is ran it will return a NULL on the first run however if called again it will return the return the intended phone number and dial it.

Answer 1

It is because, your number is null by the time you return "number". You are not waiting until the api call is complete. It is better you implement a callback when you get the response to perform specific action.