i am new to android and this my first time using AsyncTask. I made a very simple web service which returns ArrayList, like
package pk.mazars.basitMahmood.weatherReport;
public class WeekDays {
private String name;
private String weather;
private float temperature;
public WeekDays(String name, String weather, float temperature) {
this.name = name;
this.weather = weather;
this.temperature = temperature;
} //end of constructor
//--------------Getters and Setters
} //end of class WeekDays
public class WeatherReport {
public ArrayList<WeekDays> weatherReport() {
ArrayList<WeekDays> weatherList = new ArrayList<WeekDays>();
weatherList.add(new WeekDays("Monday", "Cloudy", 29.5F));
weatherList.add(new WeekDays("Tuesday", "Normal", 32.3F));
weatherList.add(new WeekDays("Wednesday", "Sunny", 37.7F));
weatherList.add(new WeekDays("Thursday", "Cold", 20.2F));
weatherList.add(new WeekDays("Friday", "Normal", 31.4F));
weatherList.add(new WeekDays("Saturday", "Rainy", 22.6F));
weatherList.add(new WeekDays("Sunday", "Rainy", 27.9F));
return weatherList;
}
} //end of class WeatherReport
Then on the android side i used the code
public class MainActivity extends Activity {
Button btnStart;
MyTask objMyTask;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
btnStart = (Button) findViewById(R.id.btnstart);
btnStart.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
objMyTask = new MyTask(MainActivity.this);
objMyTask.execute();
}
}); //end of anonymous class
} //end of onCreate()
} //end of class MainActivity
and here is my task
public class MyTask extends AsyncTask<Void, Void, ArrayList<?>> {
ProgressDialog dialog = null;
Object result = null;
MainActivity mainActivity;
public MyTask(MainActivity mainActivity) {
this.mainActivity = mainActivity ;
}
@Override
protected void onPreExecute() {
super.onPreExecute();
if (dialog == null) {
dialog = new ProgressDialog(mainActivity);
}
dialog.setMessage("Please Wait. Your authentication is in progress");
dialog.show();
} //end of onPreExecute()
@Override
protected ArrayList<?> doInBackground(Void... params) {
callWebService();
return null;
} //end of doInBackground()
@Override
protected void onPostExecute(ArrayList<?> result) {
super.onPostExecute(result);
dialog.dismiss();
} //end of onPostExecute()
} //end of class MyTask
Here is the webservice method
private void callWebService() {
...
try {
SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME);
SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER12);
envelope.dotNet = false;
envelope.setOutputSoapObject(request);
HttpTransportSE androidHttpTransport = new HttpTransportSE(URL);
androidHttpTransport.call(SOAP_ACTION,envelope);
result = envelope.getResponse();
if (result instanceof ArrayList<?>) {
ArrayList<?> weatherList = (ArrayList<?>)result;
for (int i=0; i<weatherList.size(); i++)
Object weekDay = weatherList.get(i);
System.out.println();
}
} else {
}
} catch (SocketTimeoutException e) {
Toast.makeText(mainActivity, "Service is not connected, Please make sure your server is running", Toast.LENGTH_LONG).show();
} catch(Exception e) {
e.printStackTrace();
}
} //end of callWebService()
At line
result = envelope.getResponse();
i get ArrayList like
But then i don’t know that how can i get the data from the List. After reaching line
if (result instanceof ArrayList<?>) {..}
The control is transferred to onPostExecute() method and here i get result null. How can i populate the data after getting the result from ArrayList. Also as i am trying to populate data in the callwebService method. How can i get the ArrayLIst in the onPostExecute(ArrayList<?> result)result variable. Because my method is returning ArrayList and return result is transferred to onPostExecute() method from doInBackground() method. Also in doInBackground() method where can i check for isCancel() like
@Override
protected Void doInBackground(Void... params) {
for (int i = 1; i <100; i++) {
if (isCancelled()) {
break;
} else {
System.out.println(i);
callWebService();
}
} //end of for()
return null;
} //end of doInBackground()
But if i check inside for loop, then my callWebService() method call 100 times . So in my case is there any need to call the isCancelled() method.
Thanks
Your method should be declared as
private ArrayList<?> callWebService()and you should return your arrayList from that method when you are done.Also as mentioned above you should check if your result object is returned as
Vector. If it is returned as Vector modify it to ArrayList.Finally, in the
doInBackroundof your AsyncTask you should change yourreturn nullcode toreturn callWebService();since yourcallWebService()method will return the result ArrayList with the above modification. Then in youronPostExecute(ArrayList<?> result)the result variable will not be null but will have the result ArrayList from your webservice.So with the bove modifications you will have something like this:
The AsyncTask:
You can change your Vector to Array list with something like this:
Edit(Basit)
—————————————————————
But i think this should be done in the doBackGround() method and after populating the values in the bean. Then i should use that bean in my onPostExecute() method, to update the UIThread. But this code is working fine for me.