android - 如何从 json 数组中获取整数值

Question

下面给出了我的 json 的响应，我正在尝试解析数据，但是当我解析 user_photo_id 时，它给出了 JSONException:No values for user_photo_id,谁能告诉我？

{  
  "user_login_id": "2650",  
  "user_total_photo": "3",  
  "max_upload_photo": "3",  
  "image_list": [  
    {  
      "user_photo_id": 334,  
      "status": "Approved",  
      "photo": ""  
    },  
    {  
      "user_photo_id": 394,  
      "status": "Approved",  
      "photo": ""  
    },  
    {  
      "user_photo_id": 398,  
      "status": "Admin Approve Remaining",  
      "photo": ""  
    }  
  ]  
}

我的java代码:

 class LoadImages extends AsyncTask<String, String, ArrayList<HashMap<String,String>>> {


         String photoid;
        /**
         * Before starting background thread Show Progress Dialog
         * */
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(getActivity());
            pDialog.setMessage("Loading...");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(false);
            pDialog.show();
        }
        protected ArrayList<HashMap<String,String>> doInBackground(String... args) {
            ServiceHandler sh = new ServiceHandler();

            // Making a request to url and getting response
            ArrayList<HashMap<String,String>> data = new ArrayList<HashMap<String, String>>();
            String jsonStr = sh.makeServiceCall(IMAGE_URL, ServiceHandler.GET);

            Log.d("Response: ", "> " + jsonStr);


                try {
                    jsonObj = new JSONObject(jsonStr);


                        // creating new HashMap
                        HashMap<String, String> map = new HashMap<String, String>();

                        // adding each child node to HashMap key => value
                        map.put(IMAGE_USERLOGIN_ID, jsonObj.getString(IMAGE_USERLOGIN_ID));
                        map.put(IMAGE_TOTAL_PHOTO,jsonObj.getString(IMAGE_TOTAL_PHOTO));
                        map.put(IMAGE_MAX_UPLOAD, jsonObj.getString(IMAGE_MAX_UPLOAD));
                        /*map.put(IMAGE_USER_PHOTOID, jsonObj.getString(IMAGE_USER_PHOTOID));
                        map.put(IMAGE_STATUS, jsonObj.getString(IMAGE_STATUS));
                        map.put(IMAGE_PHOTO, jsonObj.getString(IMAGE_PHOTO));
                        */




                        image_list = (JSONArray) jsonObj.get(IMAGE_LISTING);
                        for(int i=0;i< image_list.length();i++)
                        {
                           photoid += image_list.get(i);
                           Log.d("mylog", "initial marital  = " + photoid);

                        }

                          getActivity().runOnUiThread(new  Runnable() 
                     {
                        @Override
                        public void run() 
                        {
                            Intent intent=new Intent(getActivity(),PhotoView.class);
                            intent.putExtra("id", id);
                            intent.putExtra("totals", totalphota);
                            intent.putExtra("maxs", maximumphota);

                            startActivity(intent);
                        } 
                    });
                       /* image_list = (JSONArray) jsonObj.get("user_photo_id");
                        image_list=(JSONArray) jsonObj.get(IMAGE_STATUS);
                        image_list=(JSONArray)jsonObj.get(IMAGE_PHOTO);
                        for(int i=0;i< image_list.length();i++)
                        {
                          String photoid=

                        }*/

                } catch (JSONException e) {
                    e.printStackTrace();
                }


            return data;
        }


        protected void onPostExecute(ArrayList<HashMap<String,String>> result) {

            super.onPostExecute(result);


            // dismiss the dialog after getting all albums
            if (pDialog.isShowing())
                pDialog.dismiss();
            // updating UI from Background Thread
            /*Intent mIntent = new Intent(getActivity(),Filter.class);
            Bundle extras = mIntent.getExtras();
            try {
                extras.putString("radiostatus", jsonObj.getString(FILTER_ALLOW));
            } catch (JSONException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }  */


        }

    }

Answer 1

希望对您有所帮助。您只需要遵循 json 字符串的结构。 (json 数组包含 json 对象，因此首先在循环中获取 json 对象，然后从中获取 user_photo_id )

image_list = (JSONArray) jsonObj.get("image_list");
for(int i=0;i< image_list.length();i++)
{
   JSONObject imageListItem = image_list.getJSONObject(i);
   int  userPhotoId = imageListItem.getInt("user_photo_id")
   Log.d("mylog", "i ="+i+" and user_photo_id =" + userPhotoId);
}