Want to create a Generic AsyncTask

Question

In my project. For almost every Activity I have to make an AsyncTask .. And Almost the work is same for all of them. I want to create a generic AsyncTask and extends it. And i also want to send the methods in the constructor like this. Then Whenever I a class extends it . Just it have to create a method and it will do our work easily . and less coding .. It is time consuming .. Thanks for help in Advance..

One of my asyncTask is

private class GetData extends AsyncTask<String, Void, JSONObject> {

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

    progressDialog = ProgressDialog.show(Calendar.this,
            "", "");

}

@Override
protected JSONObject doInBackground(String... params) {

    String response;

    try {

        HttpClient httpclient = new DefaultHttpClient();

        HttpPost httppost = new HttpPost(url);

        HttpResponse responce = httpclient.execute(httppost);

        HttpEntity httpEntity = responce.getEntity();

        response = EntityUtils.toString(httpEntity);

        Log.d("response is", response);

        return new JSONObject(response);

    } catch (Exception ex) {

        ex.printStackTrace();

    }

    return null;
}

@Override
protected void onPostExecute(JSONObject result) 
{
    super.onPostExecute(result);

    progressDialog.dismiss();

    if(result != null)
    {
        try
        {
            JSONObject jobj = result.getJSONObject("result");

            String status = jobj.getString("status");

            if(status.equals("true"))
            {
                JSONArray array = jobj.getJSONArray("data");

                for(int x = 0; x < array.length(); x++)
                {
                    HashMap<String, String> map = new HashMap<String, String>();

                    map.put("name", array.getJSONObject(x).getString("name"));

                    map.put("date", array.getJSONObject(x).getString("date"));

                    map.put("description", array.getJSONObject(x).getString("description"));

                    list.add(map);
                }

                CalendarAdapter adapter = new CalendarAdapter(Calendar.this, list);

                list_of_calendar.setAdapter(adapter);
            }
        }
        catch (Exception e) 
        {
            e.printStackTrace();
        }
    }
    else
    {
        Toast.makeText(Calendar.this, "Network Problem", Toast.LENGTH_LONG).show();
    }
}

}

I just want to change the code in the post execute for each AsyncTask.. If I create a generic class and pass the Particular Method to it. It will be very helpful..

check out Volley, which is the recommended for many use cases to communicate with REST services by google. It can also be sleeker and less verbose than using asynctask with way more advanced features https://developers.google.com/events/io/sessions/325304728 — Patrick, May 15 '14 at 15:05

Yazan · Accepted Answer · 2014-05-16T13:58:11.103

let all your activities implements an interface say Ixxx, that has a method, activityOnPostExecute(String json), and pass the caller activity at the asyncTask constructor as type Ixxx, GenerucTask(Ixxx caller), and at postExecute() of the GenerucTask invoke caller.activityOnPostExecute(result); now at every activity override the method activityOnPostExecute().

EDIT: here is waht i mean

1- Create the interface that all activities should implement, with the onPoseExec() method:

public interface IAsyncHandler {
    public void onPostExec(String json);
}

2- Create the GenericAsyncTask class,

public class GenericAsyncTask extends AsyncTask<String, Integer, String> {
    IAsyncHandler handler = null;
    public GenericAsyncTask(IAsyncHandler h){
        handler = h;
    }
    @Override
    protected void onPreExecute() {

    }   
    @Override
    protected String doInBackground(String... params) {
        //whatever work goes here ...
        //return str as a result
        return str;
    }
    @Override
    protected void onPostExecute(String result) {
    //call the caller's class onPostExec(), it should be ovedrridden in the activity
        handler.onPostExec(result);
    }
}//CLASS

3- At your activity, override the method onPostExec()

@Override
public void onPostExec(String json) {
    // TODO Auto-generated method stub
}

4- At your activity onClick(), or somewhere execute the GenericAsyncTask

onClick(View v){
    GenericAsyncTask task = new GenericAsyncTask(this);
    task.execute("some", "params","...");
}

Want to create a Generic AsyncTask

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