Wie das JSON-Format in android

Question

Das JSON-Array erhalten Format ist

[{"restaurants": { 
    "items1": [{ 
     "id": 4, 
     "item_name": "Special Pizza", 
     "image": "" 
    }, { 
     "id": 5, 
     "item_name": "Veg Cheese Pizza", 
     "image": "" 
    }] 
    "items2": [{ 
     "id": 4, 
     "item_name": "Special Pizza", 
     "image": "" 
    }, { 
     "id": 5, 
     "item_name": "Veg Cheese Pizza", 
     "image": "" 
    }] 
}} 

ich den Wert als Eltern bekommen in Expandable ListView die item1 & item2 passieren und die item_name in Kind weitergeben. Was tun, um den übergeordneten Namen zu erhalten und in die Setter-Methode zu setzen?

class AsyncT1 extends AsyncTask<String, Void, String> { 
    @Override 
    protected String doInBackground(String... params) { 

     // http://abservetech.com/demoprojects/android/food_app/public/mobile/restaurant/restaurantresults 


     HttpClient httpclient = new DefaultHttpClient(); 
     HttpPost httppost = new HttpPost("http://abservetechdemo.com/projects/android/food_app/public/mobile/restaurant/resdetails"); 

     try { 

      List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(); 
      nameValuePairs.add(new BasicNameValuePair("res_id","1")); 
      nameValuePairs.add(new BasicNameValuePair("status","veg")); 
      nameValuePairs.add(new BasicNameValuePair("main_cat","pizza")); 

      // nameValuePairs.add(new BasicNameValuePair("group_id", group_id)); 
      httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs)); 
      Log.e("mainToPost", "mainToPost" + nameValuePairs.toString()); 


    /* execute */ 

      // Execute HTTP Post Request 
      HttpResponse response = httpclient.execute(httppost); 
      InputStream inputStream = response.getEntity().getContent(); 
      InputStreamToStringExample str = new InputStreamToStringExample(); 
      String responseServer = str.getStringFromInputStream(inputStream); 
      Log.d("response", "response -----" + responseServer); 

      JSONObject jsonRootObject = new JSONObject(responseServer); 
      JSONArray jsonArray = jsonRootObject.optJSONArray("restaurants"); 

      for (int i1 = 0; i1 < jsonArray.length(); i1++) { 
       try { 

        ArrayList<Group> list = new ArrayList<Group>(); 
        ArrayList<Child> ch_list= new ArrayList<Child>(); 

        JSONObject jsonObject = jsonArray.getJSONObject(i1); 
        Group gru = new Group(); 


        JSONArray ja = jsonObject.getJSONArray("item"); 
        Log.d("subcategory---",s_category); 
        gru.setName(jsonObject.getJSONArray("items").toString()); 
        for (int i = 0; i < ja.length(); i++) { 

         JSONObject jo = ja.getJSONObject(i); 

         Child ch = new Child(); 

         ch.setName(jo.getString("item_name").toString()); 


         ch_list.add(ch); 
        } // for loop end 
        gru.setItems(ch_list); 
        list.add(gru); 
        ExpAdapter = new ExpandListAdapter(
          Expand.this, list); 
        runOnUiThread(new Runnable() { 
         @Override 
         public void run() { 
        ExpandList.setAdapter(ExpAdapter);}}); 

       } 
       catch (JSONException e) { 

        e.printStackTrace(); 
       } 


      } 
     } catch (Exception e) { 
      e.printStackTrace(); 
     } 
     return null; 
    } 

    @Override 
    protected void onPostExecute(String aVoid) { 
     super.onPostExecute(aVoid); 


    } 
} 

Logcat Fehler:

 W/System.err: java.lang.NullPointerException 
06-30 12:30:39.260 26691-26744/abservetech.com.foodapp W/System.err:  at abservetech.com.foodapp.Expand$AsyncT1.doInBackground(Expand.java:84) 
06-30 12:30:39.260 26691-26744/abservetech.com.foodapp W/System.err:  at abservetech.com.foodapp.Expand$AsyncT1.doInBackground(Expand.java:50) 
06-30 12:30:39.260 26691-26744/abservetech.com.foodapp W/System.err:  at android.os.AsyncTask$2.call(AsyncTask.java:288) 
06-30 12:30:39.260 26691-26744/abservetech.com.foodapp W/System.err:  at java.util.concurrent.FutureTask.run(FutureTask.java:237) 
06-30 12:30:39.260 26691-26744/abservetech.com.foodapp W/System.err:  at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231) 
06-30 12:30:39.260 26691-26744/abservetech.com.foodapp W/System.err:  at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112) 
06-30 12:30:39.260 26691-26744/abservetech.com.foodapp W/System.err:  at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587) 
06-30 12:30:39.260 26691-26744/abservetech.com.foodapp W/System.err:  at java.lang.Thread.run(Thread.java:841) 

Answer 1

Das erste, was Restaurants ist ein JSON-Objekt nicht Json-Array. Um Ihre Gruppen es tun mögen diese

JSONObject jsonRootObject = new JSONObject(responseServer); 
JSONObject jsonobject=jsonRootObject.getJSONObject("restaurants"); 
JSONArray item1=jsonobject.getJSONArray("items1"); 
JSONArray item2=jsonobject.getJSONArray("items2"); 
for(int i=0;i<item1.length();i++) 
{ 
JSONObject json=item1.getJSONArray(i); 
String item_name=json.getString("item_name"); 
}