<uses-permission android:name="android.permission.INTERNET" />


public class GetAsync extends AsyncTask<String, String, String> {

    private Map<String, String> methods;
    private JSONObject jsonObject;
    private CallBackJSON callBackJSON;

    public GetAsync(Map<String, String> methods, CallBackJSON callBackJSON) {
        this.methods = methods;
        this.callBackJSON = callBackJSON;
    }

    @Override
    protected String doInBackground(String... strings) {
        try {
            URL url = new URL(strings[0]);
            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setRequestMethod("GET");
            for (String key : methods.keySet()) connection.addRequestProperty(key, methods.get(key));
            InputStreamReader inputStreamReader = new InputStreamReader(connection.getInputStream());
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
            StringBuilder builder = new StringBuilder();
            String line;
            while ((line = bufferedReader.readLine()) != null){
                builder.append(line);
            }
            jsonObject = new JSONObject(builder.toString());
        }catch (Exception e){ e.printStackTrace();}
        return null;
    }

    @Override
    protected void onPostExecute(String s) {
        super.onPostExecute(s);
        try {
            callBackJSON.onCallBack(jsonObject);
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }
}




public class PostAsync extends AsyncTask<String, String, String> {

    private JSONObject jsonObject;
    private CallBackJSON callBack;
    private JSONObject result;


    public PostAsync(JSONObject jsonObject, CallBackJSON callBack) {
        this.jsonObject = jsonObject;
        this.callBack = callBack;
    }

    @Override
    protected String doInBackground(String... strings) {
        try {
            URL url = new URL(strings[0]);
            HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
            httpURLConnection.setRequestMethod("POST");
            httpURLConnection.setDoInput(true);
            httpURLConnection.setDoOutput(true);
            httpURLConnection.addRequestProperty("Content-Type", "application/json");
            httpURLConnection.setRequestProperty("Token", User.getInstance().getToken() + "");
            httpURLConnection.connect();
            OutputStream outputStream = httpURLConnection.getOutputStream();
            BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(outputStream));
            writer.write(jsonObject.toString());
            writer.flush();
            InputStreamReader inputStreamReader = new InputStreamReader(httpURLConnection.getInputStream());
            BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
            String line;
            StringBuilder builder = new StringBuilder();
            while ((line = bufferedReader.readLine()) != null) {
                builder.append(line);
            }
            result = new JSONObject(builder.toString());
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(String s) {
        super.onPostExecute(s);
        try {
            callBack.onCallBack(result);
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }


}


//image
InputStream in = new URL(strings[0]).openStream();
bitmap = BitmapFactory.decodeStream(in);



//adapter


public class ProductAdapter extends RecyclerView.Adapter<ProductAdapter.ProductHolder> {

    private List<IProduct> list;
    private LayoutInflater layoutInflater;

    public ProductAdapter(List<IProduct> list, Context context) {
        this.list= list;
        this.layoutInflater = LayoutInflater.from(context);
    }

    public void setProducts(List<IProduct> list) {
        this.list= list;
    }

    @Override
    public ProductHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = layoutInflater.inflate(R.layout.product_item, parent, false);
        return new ProductHolder(view);
    }

    @RequiresApi(api = Build.VERSION_CODES.O)
    @Override
    public void onBindViewHolder(ProductHolder holder, int position) {

    }


    @Override
    public int getItemCount() {


        return колво значений;
    }

    public class ProductHolder extends RecyclerView.ViewHolder{

        public ProductHolder(View itemView) {
            super(itemView);

        }


    }