Question

json数组格式为

[{"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": ""
    }]
}}

我想获得item1＆amp; item2将值作为Expandable ListView中的父项传递，并将item_name传递给child。如何获取父名称并设置为setter方法？

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错误：

     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

第一件餐馆是json对象而不是json数组。让你的小组像这样做

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");
}

如何在android中获取Json格式

1 个答案: