安卓 : Synchronous way to use asyncttask : Json upload issue

Question

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我正在尝试以 json 格式发送多个学生数据及其响应。

问题

当表中有多行时。该功能一次发出多个请求。然后我从回调函数中得到多个响应...我想要一个请求及其回调。然后提出新的要求

我要这个

 final ConnectToServer connect = new ConnectToServer();
            connect.extConnectToServer(AdminSection.this,new ConnectToServer.Callback() 

在每次请求发出后调用的函数。整个循环完成后调用回调函数。

代码

 public void Uploadalldata()
        {    
            if(isOnline())
            {   
              JSONObject StudentData = new JSONObject();    
               try
                 {

             String android_id = Secure.getString(this.getContentResolver(),Secure.ANDROID_ID);
             DBHelper db = new DBHelper(getApplicationContext());
             List<StudentClass> StudentDataAll = db.getAllStudentData();
             for(int iCount=0; iCount< StudentDataAll.size(); iCount++)
                {
                 StudentClass objStudentClass= (StudentClass)StudentDataAll.get(iCount);
                 String sSingleStudentCompleteDetails= android_id +","+ objStudentClass.RegistrationId + "," + objStudentClass.Name + "," + objStudentClass.SchoolID + "," + objStudentClass.Class + "," + objStudentClass.RollNo + "," + objStudentClass.RegistrationDate;
                 String sSingleStudentCompleteResponse = "";     
                 String strStudentID = objStudentClass.RegistrationId;       
                 StudentIDForSave = strStudentID;

                 List<StudentResponse> StudentResponse = db.getStudentResponseOnStudentID(strStudentID);

                    for(int iOptionCount=0; iOptionCount<StudentResponse.size(); iOptionCount++)
                        {

                           StudentResponse objStudentResponse=StudentResponse.get(iOptionCount);
                           if(iOptionCount>0) 
                        sSingleStudentCompleteResponse += ",";

                        sSingleStudentCompleteResponse += objStudentResponse.QuestionID + "-" + objStudentResponse.OptionID;

                        }
                    StudentData.put("StudentDetails", sSingleStudentCompleteDetails);
                    StudentData.put("Responses", sSingleStudentCompleteResponse);

                    JSONObject finaldata = new JSONObject();
                    finaldata.put("RegisterStudentRequest", StudentData);

         final ConnectToServer connect = new ConnectToServer();
            connect.extConnectToServer(AdminSection.this,new ConnectToServer.Callback() 
            {
                public void callFinished(String result)
                {
                    JSONObject resp = null;

                    try 
                    {
                        resp = new JSONObject(result);
                        JSONObject UploadStudentDataResult = resp.getJSONObject("RegisterStudentResult");

                        String strMessage = UploadStudentDataResult.getString("IsUploaded");

                        if (StudentIDForSave != null)
                        {
                            SQLiteDatabase db;
                            ContentValues values = new ContentValues();
                            values.put(DBHelper.isUploaded, strMessage);


                        // Call update method of SQLiteDatabase Class and close after
                        // performing task
                        db = helper.getWritableDatabase();
                        db.update(DBHelper.TABLEStudent, values, DBHelper.S_ID + "=?",
                                new String[] { StudentIDForSave});
                        db.close();
                        //Toast.makeText(getBaseContext(), "saved", Toast.LENGTH_LONG).show();
                        }
//                      else
//                      {
//                          Toast.makeText(getBaseContext(), "Data not saved", Toast.LENGTH_LONG).show();
//                      }

                    }


                    catch (final JSONException e)
                    {

                    }

                }
                    }, "http://myurl/Service/RegisterStudent", finaldata, "POST");
                connect.execute(finaldata).get();


     }

 }
  catch (Exception e) {
     Log.d("InputStream", e.getLocalizedMessage());
}
            }
     }

Answer 1

As per the docs here ，可以通过使用“get()”方法同步使用 AsyncTask 类。

一个简单的例子:

MyAsyncTask task = new MyAsyncTaskTask();
String result = task.execute().get();

class MyAsyncTask extends AsyncTask<Void,Void,String>{...}

根据其中一条评论，Volley 还具有异步运行的能力。