在线更新列表视图内容

时间:2018-08-12 10:22:27

标签: android json listview caching

我正在使用齐射从json提取数据,我想将数据添加到缓存中。我添加到缓存中,它在脱机模式下可以正常工作,但是在在线模式下,由于从json API中获取数据,每个数据都增加了一倍。因此,我的问题是如何在向用户显示我的缓存数据之前,先获取json数据,然后再显示新数据并使用新数据更新缓存。

这是我的代码,读取缓存的数据并获取在线数据:

     @Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    View v=inflater.inflate(R.layout.fragment_tab1, container, false);


    list1=(ListView)v.findViewById(R.id.kunlist);
    list2=(ListView)v.findViewById(R.id.oylist);
    list3=(ListView)v.findViewById(R.id.haflist);
    listitem=new ArrayList<>();
    itemList2=new ArrayList<>();
    itemList3=new ArrayList<>();
    loadfirst();
    loadingView();
    // Inflate the layout for this fragment
    return v;
}

private void loadingView() {

    StringRequest request=new StringRequest(Request.Method.GET, URL_Data,
            new Response.Listener<String>() {
                @Override
                public void onResponse(String response) {

                    try {
                        JSONObject jsonObject=new JSONObject(response);
                        JSONObject array=jsonObject.getJSONObject("data");


                        ObjectOutput out=new ObjectOutputStream(new FileOutputStream(new File(activity2.getCacheDir(),"")+File.separator+"cache.srl"));
                        out.writeObject(array.toString());
                        out.close();

                   jsonRead(array);

                    } catch (JSONException e) {
                        Toast.makeText(getContext(), e.getMessage(), Toast.LENGTH_LONG).show();
                        e.printStackTrace();
                    } catch (UnsupportedEncodingException e) {
                        e.printStackTrace();
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }

                }
            },
            new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    Activity activity = getActivity();
                    if(activity != null && isAdded()&&getContext()!=null)
                        Toast.makeText(getContext(),"Internet problem",Toast.LENGTH_SHORT).show();
                }
            });
    RequestQueue requestQueue= Volley.newRequestQueue(context);
    requestQueue.add(request);
}

  public void loadfirst(){
    try{
        ObjectInputStream in=new ObjectInputStream(new FileInputStream(new File(activity2.getCacheDir()+File.separator+"cache.srl")));

 JSONObject jObject=new JSONObject((String)in.readObject());
        in.close();
        jsonRead(jObject);
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (StreamCorruptedException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    } catch (JSONException e) {
        e.printStackTrace();
    }
}
public void jsonRead(JSONObject obj) throws JSONException, UnsupportedEncodingException {
    JSONArray day=obj.getJSONArray("day");
    JSONArray week=obj.getJSONArray("week");
    JSONArray month=obj.getJSONArray("month");

    KunItem item=null;
    KunItem kun=null;
    KunItem hafta=null;
    for(int i=0;i<day.length();i++) {
        JSONObject o = day.getJSONObject(i);

        if (Tab1.this.res.getConfiguration().locale.getLanguage().equals("uz")) {
            item = new KunItem(
                    o.getString("name_uz"),
                    o.getString("price"),
                    o.getString("activation_code")
            );

        } else if (Tab1.this.res.getConfiguration().locale.getLanguage().equals("ru")) {

            item = new KunItem(
                    URLDecoder.decode(URLEncoder.encode(o.getString("name_ru"), "iso8859-1"), "UTF-8"),
                    o.getString("price"),
                    o.getString("activation_code"));

        }

        listitem.add(item);
        adapter = new KunAdapter(context, listitem);

        list1.setAdapter(adapter);
    }
    for(int i=0;i<week.length();i++) {
        JSONObject o = week.getJSONObject(i);

        if (Tab1.this.res.getConfiguration().locale.getLanguage().equals("uz")) {

            kun = new KunItem(
                    o.getString("name_uz"),
                    o.getString("price"),
                    o.getString("activation_code")
            );
        }
        else if (Tab1.this.res.getConfiguration().locale.getLanguage().equals("ru")) {

            kun = new KunItem(

                    URLDecoder.decode(URLEncoder.encode(o.getString("name_ru"), "iso8859-1"), "UTF-8"),
                    o.getString("price"),
                    o.getString("activation_code"));


        }

        itemList2.add(kun);
        adapter2 = new KunAdapter(context, itemList2);
        list3.setAdapter(adapter2);
    }
    for(int i=0;i<month.length();i++) {
        JSONObject o = month.getJSONObject(i);

        if (Tab1.this.res.getConfiguration().locale.getLanguage().equals("uz")) {

            hafta = new KunItem(
                    o.getString("name_uz"),
                    o.getString("price"),
                    o.getString("activation_code")
            );


        } else if (Tab1.this.res.getConfiguration().locale.getLanguage().equals("ru")) {
            hafta = new KunItem(

                    URLDecoder.decode(URLEncoder.encode(o.getString("name_ru"), "iso8859-1"), "UTF-8"),
                    o.getString("price"),
                    o.getString("activation_code")
            );
        }
        itemList3.add(hafta);
        adapter3=new KunAdapter(context,itemList3);

        list2.setAdapter(adapter3);
    }
}

1 个答案:

答案 0 :(得分:1)

您必须这样做

1-通过内部数据库中的数据显示列表视图(如果有)

2-从服务器获取新数据

3-清除内部数据库中的先前数据(如果成功完成)

4-在内部数据库中保存新数据

5-使用列表视图向用户显示提取的数据