Wsrtjtyk

There I am getting data from SQLite and send it to the server using Volley.
for now, I am sending all the data at a time.
I just want to know how can I create a queue that first data of one vehicle, gets its response and then send another one.

cursor=helperClass.readAllData();

                if (cursor!=null)

                {

                    while (cursor.moveToNext())

                    {

                        modelClass=new ModelClass(cursor.getInt(0),cursor.getString(1),

                                cursor.getString(2),cursor.getString(3),

                                cursor.getString(4),cursor.getString(5));

                                modelClasses.add(modelClass);

                    }



                    sizeOfArray=modelClasses.size();



                    for (int i=0; i<sizeOfArray;i++)

                    {

                        name = modelClasses.get(i).getName();

                        model=modelClasses.get(i).getModelName();

                        number=modelClasses.get(i).getEngineNumber();

                        image=modelClasses.get(i).getImageBase64();

                        hdimage=modelClasses.get(i).getHdimageBase64();

                        uploadData(name, model, number, image, hdimage);

                        Toast.makeText(UploadDataServiceClass.this, String.valueOf(sizeOfArray), Toast.LENGTH_SHORT).show();

                        Toast.makeText(UploadDataServiceClass.this, String.valueOf(i), Toast.LENGTH_SHORT).show();

                    }



                }

uploadData(name,model,number,image,hdimage)

        RequestQueue requestQueue=Volley.newRequestQueue(UploadDataServiceClass.this);

    StringRequest stringRequest=new StringRequest(Request.Method.POST, showURL, new Response.Listener<String>()

    {

        @Override

        public void onResponse(String response)

        {

            try

            {

                Log.d(TAG, "onResponse: " + response);

                JSONObject jsonObject = new JSONObject(response);



            }

            catch (JSONException e)

            {

                e.printStackTrace();                   

            }

        }

    }, new Response.ErrorListener()

    {

        @Override

        public void onErrorResponse(VolleyError error)

        {   }

    }

    )

    {

        @Override

        protected Map<String, String> getParams()

        {

            Map<String, String> parameters = new HashMap<String, String>();

            parameters.put("name", name);

            parameters.put("model", model);

            parameters.put("number", number);

            parameters.put("image", image);

            parameters.put("hdimage", hdimage);

            parameters.put("crud_type", "insert");

            return parameters;

        }

    };

    requestQueue.add(stringRequest);

You need a Executor Service with singleThreadExecutor to execute your threads one by one

Creates an Executor that uses a single worker thread operating off an unbounded queue. (Note however that if this single thread terminates due to a failure during execution prior to shutdown, a new one will take its place if needed to execute subsequent tasks.) Tasks are guaranteed to execute sequentially, and no more than one task will be active at any given time. Unlike the otherwise equivalent newFixedThreadPool(1) the returned executor is guaranteed not to be reconfigurable to use additional threads.

but what is Executor Service ?




with a Executor Service you can set the maximum running tasks (1 in your case)



here is a simple tutorials about ThreadPool , Executors and Future