什么是序列化AsyncTasks的最佳实践？

Question

我一直在研究一个完全依赖于本地服务器上数据库信息的android应用程序（信息以来自web服务的json数组的形式出现）。

所以我一直在使用多个AsyncTasks，我将在OnCreate中执行第一个，而第二个将在第一个的OnPostExecute中，因此链接。 我的问题是什么是最好的做法？我的意思是让一个AsyncTask执行我所有的http get / post请求会更好吗？ 这是我的代码示例： 第一个http AsyncTask的代码：

public class httpAddProduct extends AsyncTask<Void,Void,String> {
        String  rs;

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            dd_dialog=showProgressDialog();
        }

        @Override
        protected String doInBackground(Void... params) {
            try {
                String proID=selectedCatProID.get(itemIndex);
                String link = "http://"+IP+"/H2O.asmx/Add_Product?OrderID="+orderId+"&ItemNo="+proID
                        +"&Qty="+Qyt;
                HttpClient client = new DefaultHttpClient();
                HttpGet request = new HttpGet();
                request.setURI(new URI(link));
                client.execute(request);
                addPro=true;
                isChanged=true;
                rs = "sucessful";
            } catch (Exception e) {
                rs = "Fail";
            }
            return rs;
        }
        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);
            if(s.equals("sucessful")){
                new httpGetOrder().execute();
dd_dialog.hide();
        }}

    } 

这是第二个http代码：

public class httpGetOrder extends AsyncTask<Void,Void,String> {
        String result, rs;
        JSONArray jArray;
        Boolean isEmpty=true;

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
        }

        @Override
        protected String doInBackground(Void... params) {
            try {
                String link = "http://"+IP+"/H2O.asmx/Get_Order?OrderID="+orderId;
                HttpClient client = new DefaultHttpClient();
                HttpGet request = new HttpGet();
                request.setURI(new URI(link));
                HttpResponse response = client.execute(request);
                BufferedReader reader = new BufferedReader(new InputStreamReader(response.getEntity().getContent(), "UTF-8"), 8);
                StringBuilder sb = new StringBuilder();
                String line = null;
                while ((line = reader.readLine()) != null) {
                    sb.append(line + "\n");
                }
                result = sb.toString();
                String[] separated = result.split(">");
                JSONObject jObject = new JSONObject(separated[2]);
                jArray = jObject.getJSONArray("OrderItems");
                lineIDs = new ArrayList<>();
                productNames = new ArrayList<>();
                QYTs = new ArrayList<>();
                unitPrice = new ArrayList<>();
                subtotal = new ArrayList<>();
                FatherCateg=new ArrayList<>();
                isPrinted1=new ArrayList<>();
                isPrinted2=new ArrayList<>();
                isPrinted3=new ArrayList<>();
                note=new ArrayList<>();
                isEmpty=true;
                int jlen=jArray.length();
                if(jlen>0) {
                    for (int i = 0; i < jlen; i++) {
                        if(jArray.getJSONObject(i)!=null) {
                            JSONObject json_data = jArray.getJSONObject(i);
                            lineIDs.add(json_data.getString("LineID"));
                            productNames.add(json_data.getString("En_Name"));
                            unitPrice.add(json_data.getString("UnitPrice"));
                            subtotal.add(json_data.getString("SubTotal"));
                            QYTs.add(json_data.getString("Qty"));
                            FatherCateg.add(json_data.getString("Father"));
                            note.add(json_data.getString("LineNote"));
                            isPrinted1.add(json_data.getString("IsPrinted"));
                            isPrinted2.add(json_data.getString("IsPrinted2"));
                            isPrinted3.add(json_data.getString("IsPrinted3"));
                        }

                    }
                    isEmpty=false;
                }
                rs = "sucessful";
            } catch (Exception e) {
                rs = e.getMessage();
            }
            return rs;
        }
        @Override
        protected void onPostExecute(String s) {
            super.onPostExecute(s);
            if(s.equals("sucessful")){
                try{

                    if(isEmpty){
                        grandt.setText("0");
                        invoiceList.setAdapter(null);
                        dd_dialog.hide();
                    }else{
                        makeInvoice();
                        listviewAdapter adapter = new listviewAdapter(SelectCategory.this, list);
                        invoiceList.setAdapter(adapter);

                        if(addPro)
                        {invoiceList.setSelection(adapter.getCount()-1); addPro=false;}
                        else
                            invoiceList.setSelection(selectionIndex);

                        new httpGetTotal().execute();
                    }}
                catch (Exception e){
                    Toast.makeText(context, e.getMessage(), Toast.LENGTH_SHORT).show();
                }}

        }

    }

然而这激发了第三个AsyncTask。 我知道代码太长了：/抱歉 但我的应用越来越慢，我需要提出这个问题的建议。