How to set time out for AsyncTask execution? - android

I have been trying to create time out while AsyncTask execution more than 1 minute. If the time up, then should exit with Notification.
This is my code:
private class GetLongLat extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
longlatDialog = new ProgressDialog(MainActivity.this);
longlatDialog.setMessage("Fetching Data. Please wait..");
longlatDialog.setCancelable(false);
longlatDialog.show();
}
#Override
protected Void doInBackground(Void... arg0) {
GPSTracker gpsTracker;
//This is the timer to set time out
Timer timer = new Timer();
timer.schedule(new TaskKiller(this), 3000);
timer.cancel();
do{
gpsTracker = new GPSTracker(MainActivity.this);
gpsTracker.getLocation();
}while(!String.valueOf(gpsTracker.latitude).equals("0.0"));
return null;
}
protected void onCancelled() {
// do something, inform user etc.
Toast.makeText(getApplicationContext(), "Failed getting long lat. Please check your internet connection", Toast.LENGTH_LONG).show();
System.exit(1);
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
if (longlatDialog.isShowing())
longlatDialog.dismiss();
}
}
And this is a class called in doInBackground to set the time up.
class TaskKiller extends TimerTask {
private AsyncTask<?, ?, ?> mTask;
public TaskKiller(AsyncTask<?, ?, ?> task) {
this.mTask = task;
}
public void run() {
mTask.cancel(true);
}
}
But when i run the code, nothing happen. I mean the progress dialog always run very long time.
EDIT
I have edit my code to call GetLongLat something like this:
GetLongLat n = new GetLongLat();
n.execute();
try {
n.get(3000, TimeUnit.MILLISECONDS);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ExecutionException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (TimeoutException e) {
// TODO Auto-generated catch block
Toast.makeText(getApplicationContext(), "Failed getting long lat. Please check your internet connection", Toast.LENGTH_LONG).show();
System.exit(1);
}
But also, doesn't work.

I think you can use AsyncTask.get()
GetLongLat n = new GetLongLat();
n.get(30000, TimeUnit.MILLISECONDS);
you will have to use the n.get in a separate Thread..
Edited: one more different method but not efficient.,
GetLongLat n = new GetLongLat();
n.execute();
Handler handler = new Handler();
handler.postDelayed(new Runnable()
{
#Override
public void run() {
if ( n.getStatus() == AsyncTask.Status.RUNNING )
n.cancel(true);
}
}, 30000 );

why are you canceling the timer? just after calling schedule()?
Cancels the Timer and all scheduled tasks
timer.cancel(); should be removed. check docs for cancel()

You can achieve this behaviour in many ways.
Here's an example using CountDownTimer
// Start your AsyncTask
private YourAsyncTask mTask = new YourAsyncTask().execute();
// Run a timer after you started the AsyncTask
new CountDownTimer(60000, 1000) {
public void onTick(long millisUntilFinished) {
// Do nothing
}
public void onFinish() {
mTask.cancel(true);
}
}.start();
You are cancelling the timer just after initiating it. You can do it like this too. But this type of busy waiting is not recommended at all.
#Override
protected Void doInBackground(Void... arg0) {
GPSTracker gpsTracker;
//This is the timer to set time out
new CountDownTimer(60000, 1000) {
public void onTick(long millisUntilFinished) {
// Do nothing
}
public void onFinish() {
// Set latitude to zero to finish the while loop outside.
// gpsTracker.latitude = "0.0"; // Something like this
}
}.start();
do{
gpsTracker = new GPSTracker(MainActivity.this);
gpsTracker.getLocation();
}while(!String.valueOf(gpsTracker.latitude).equals("0.0"));
return null;
}

Here's another approach. In your doInBackground method, you can use System.currentTimeMillis to check whether 1 minute has elapsed or not.
protected Void doInBackground(Void... arg0) {
GPSTracker gpsTracker;
long startTime = System.currentTimeMillis();
do{
gpsTracker = new GPSTracker(MainActivity.this);
gpsTracker.getLocation();
}while(!String.valueOf(gpsTracker.latitude).equals("0.0")
&& ((System.currentTimeMillis() - startTime) <= 60000);//60000 millisecond = 1 minute
return null;
}
`

Just alter your code like this and check whether your async task is getting cancelled or not.
GetLongLat getLongLatAsync = new GetLongLat();
getLongLatAsync.execute();
try {
Handler handler = new Handler();
/** 1st method **/
handler.postDelayed(new Runnable()
{
#Override
public void run() {
if (getLongLatAsync.getStatus() == AsyncTask.Status.RUNNING )
getLongLatAsync.cancel(true);
}
}, 3000 ); //3 Seconds
/** 1st method ends **/
/** second method */
handler.post(new Runnable()
{
#Override
public void run() {
getLongLatAsync.get(3000, TimeUnit.MILLISECONDS);//You should run it in seperated thread or else it will block ui thread.
}
});
/** Second method ends**/
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ExecutionException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (TimeoutException e) {
// TODO Auto-generated catch block
Toast.makeText(getApplicationContext(), "Failed getting long lat. Please check your internet connection", Toast.LENGTH_LONG).show();
}
and in the onCancelld method write your logic
#Override
protected void onCancelled() {
Log.d(TAG,"Asynctask has been cancelled.");
}

Related

Wait for thread to finish and then move to next position

i am trying to display a Toast on the screen and when Toast fades off then move to the next question. I have tried with Thread but cannot seem to manage.
My code:
next.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (getUserSelection()){
position = position + 3;
if (position < questionsArray.size()) {
curName = questionsArray.get(position).getName();
curArray = questionsArray.get(position).getAnswers();
curIscorrect = questionsArray.get(position).getIscorrect();
setupQuestionView(curName, curArray, curIscorrect);
} else {
StringGenerator.showToast(QuestionsActivity.this, "Your score : " + score + "/" + (questionsArray.size() / 3));
}
}else {
StringGenerator.showToast(QuestionsActivity.this, getString(R.string.noanswerselected));
}
}
});
and the getUserSelectionMethod:
private boolean getUserSelection() {
correct = (RadioButton)findViewById(group.getCheckedRadioButtonId());
if (correct == null){
return false;
}else {
correctAnswerText = correct.getText().toString();
if (map.get(correctAnswerText).equals(Constants.CORRECTANSWER)) {
score++;
setCorrectMessage();
return true;
} else {
setWrongMessage();
return true;
}
}
}
private void setCorrectMessage() {
correctToast = new Toast(QuestionsActivity.this);
correctToastView = getLayoutInflater().inflate(R.layout.correct, (ViewGroup) findViewById(R.id.correctRootLayout));
correctText = (TextView)correctToastView.findViewById(R.id.correctTextView);
correctText.setText(getString(R.string.correctAnswer));
correctToast.setDuration(Toast.LENGTH_SHORT);
correctToast.setView(correctToastView);
correctToast.show();
correctThread = new Thread(new Runnable() {
#Override
public void run() {
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
correctToast.cancel();
}
});
correctThread.start();
}
private void setWrongMessage() {
wrongToast = new Toast(QuestionsActivity.this);
wrongToastView = getLayoutInflater().inflate(R.layout.wrong, (ViewGroup) findViewById(R.id.wrongRootLayout));
wrongText = (TextView)wrongToastView.findViewById(R.id.wrongTextView);
wrongText.setText(getString(R.string.wrongAnswer));
wrongToast.setDuration(Toast.LENGTH_SHORT);
wrongToast.setView(wrongToastView);
wrongToast.show();
wrongThread = new Thread(new Runnable() {
#Override
public void run() {
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
wrongToast.cancel();
}
});
wrongThread.start();
}
Any suggestion on how to do this?
You can determine the toast visibility:
toast.getView().getWindowToken()
If the result is null, than your toast isn't visible anymore, and than you can run any code you want.
as stated in this answer you can start a thread that waits the duration of the Toast:
Thread thread = new Thread(){
#Override
public void run() {
try {
Thread.sleep(3500); // 3.5seconds!
// Do the stuff you want to be done after the Toast disappeared
} catch (InterruptedException e) {
e.printStackTrace();
}
}
};
Toast.LENGTH_SHORT and Toast.LENGTH_LONG are only flags so you have to either hard code the duration or keep them in a constant. The durations are 3.5s (long) and 2s (short).
If you want to manipulate some of your views, you cannot do this in another thread than the "main" UI thread. So you have to implement a kind of callback/polling mechanism to get notified when the SleepThread has finished.
Check this answer to read about a couple of ways to do this. Probably the easiest of them to understand and implement is this:
After you started your Thread you can check if it is still alive and running by calling thread.isAlive(). In this way you can do a while loop that runs while the thread is running:
// start your thread
while(thread.isAlive()){}
// continue the work. The other thread has finished.
Please note that this is NOT the most elegant way to do this! Check the other possibilities in the answer I've mentioned above for more elegant solutions (especially the last one with the listeners is very interesting and worth reading!)
That's because the Thread class is purely executed in the background and you need to manipulate the view in the Main thread. To solve your issue just replace the Thread with AsynTask.
AsyncTask<Void,Void,Void> a = new AsyncTask<Void, Void, Void>() {
#Override
protected Void doInBackground(Void... params) {
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
correctToast.cancel();
}
};
a.execute();
If you look at my code you can see my onPostExecute, this method is called in the Main Thread.
My Error was because i was trying to acess UI Elements through another Thread so modifying the code like this:
Thread thread = new Thread(new Runnable() {
#Override
public void run() {
try {
Thread.sleep(500);
QuestionsActivity.this.runOnUiThread(new Runnable() {
#Override
public void run() {
moveToNextQuestion();
}
});
} catch (InterruptedException e) {
e.printStackTrace();
}
}
});
thread.start();
did the trick. I hope my answer helps someone!!!

Android listview timer run in every second

I have a issue with using a timer on a listview.
In the list item I showed using sqlite values. There is a textview which showing time difference of last updated time of the data and current time. i have to show it in every one second. so the user can know how long he updated the record.
I tried this in several ways.
First way
I tried to add timer in adapter class. so for every item new timer is created. so application crashed because of many timers run simultaneously.
Second way
I tried using adapter.notifyDataSetChanged() way. Like as this.
Handler timerHandler = new Handler();
Runnable timerRunnable = new Runnable() {
#Override
public void run() {
if (adapterChatThread != null) {
adapter.notifyDataSetChanged();
}
timerHandler.postDelayed(this, 1000); // run every second
}
};
timerRunnable.run();
I move to another activity when click on list item and user can come back to this Activity.
so in Onresume I used
timerHandler.postDelayed(timerRunnable, 500);
and OnPause
timerHandler.removeCallbacks(timerRunnable);
Issue is data is not showing well. I mean in every second data difference is not one second. some time differnce is 2sec, 5 sec, .. etc.
means timer is not working as I expected.
Third way
I used a asynctask and call it in every second using a timer.
class ThreadTimer extends AsyncTask<Void, Void, Void> {
#Override
protected Void doInBackground(Void... params) {
return null;
}
#Override
protected void onPostExecute(Void result) {
if (adapter != null)
adapter.notifyDataSetChanged();
super.onPostExecute(result);
}
}
I called this as in here
Handler timerHandler = new Handler();
Runnable timerRunnable = new Runnable() {
#Override
public void run() {
new ThreadTimer().execute();
timerHandler.postDelayed(this, 1000); // run every second
}
};
timerRunnable.run();
previous issue triggered. (data not showing well)
Fourth way
Using AsyncTask as this
class ThreadTimer extends AsyncTask<Void, Void, Void> {
void Sleep(int ms) {
try {
Thread.sleep(ms);
} catch (Exception e) {
}
}
#Override
protected Void doInBackground(Void... params) {
while (threadRun) {
Sleep(1000);
return null;
}
return null;
}
#Override
protected void onPostExecute(Void result) {
adapter.notifyDataSetChanged();
super.onPostExecute(result);
}
}
I called this class in OnResume.
In on pause I set threadRun= false;
issue is same.
please help me.
My requirement is update list item in every second.
Thank you.
edit
here is my adapter class textview update code.
Date lastUpdatedTime;
final ChatThreadDAO ctd = new ChatThreadDAO();
long timeForNextResponse = ctd.getLastRespondedTime(vct.get(position).getThread_id());
try {
if (vct.get(position).getThread_read_status() == 1 && timeForNextResponse > 0) {
final long respTime = timeForNextResponse;
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
lastUpdatedTime = formatter.parse(vct.get(position).getLast_updated_time());
final long timeDiff = (new Date()).getTime() - lastUpdatedTime.getTime();
if (timeDiff <= respTime) {
timeForNextResponse = respTime - timeDiff;
ctd.updateTimeRespondToLastMsg(vct.get(position).getThread_id(), timeForNextResponse);
holder.tvChatTimer.setVisibility(View.VISIBLE);
holder.tvChatTimer.setText(timeForNextResponse / 1000 + "");
} else {
ctd.updateTimeRespondToLastMsg(vct.get(position).getThread_id(), 0);
}
} else {
holder.tvChatTimer.setVisibility(View.INVISIBLE);
}
} catch (ParseException e) {
e.printStackTrace();
}
here vct is
Vector vct;
I assign the values to vector in adapter class constructer.
Here is an example similar to your case.
private class connectionControl extends Thread {
boolean stop_ = false;
public void stop_() {
this.stop_ = true;
}
public void run() {
System.out.println("Thread started:" + getClass().getSimpleName());
while(!this.stop_) {
try {
Thread.sleep(1000);
runOnUiThread(new Runnable() {
#Override
public void run() {
// TODO Auto-generated method stub
Calendar c = Calendar.getInstance();
int rightNow = c.get(Calendar.SECOND) + c.get(Calendar.MINUTE)*60;
if(rightNow - lastUpdatedTime > 10) {
wirelessIcon.setImageResource(R.drawable.wirelessred);
}
else if(rightNow - lastUpdatedTime > 5) {
wirelessIcon.setImageResource(R.drawable.wirelessyellow);
}
else {
wirelessIcon.setImageResource(R.drawable.wirelessgreen);
}
}
});
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
System.out.println("Thread stoped:" + getClass().getSimpleName());
}
}
You set your lastUpdatedTime the same way you created rightNow whenever you call notifyDataSetChanged() method of your adapter.

Android Timed Async Task

Hi currently i have the following code which utilizes Asycn Task and Timer.
My async task is basically trying to send a HTTP GET method from a URL where the response from the server could varies depending on connection and load.
What i would like to do is to have a timed async task. Where, it will schedule an AsyncTask every X second BUT if there is currently an Async Task in progress i would have to kill it first. Then start a new one.
Here is the code that i have at the moment:
private static boolean running = false;
Timer myTimer;
protected void onCreate(Bundle savedInstanceState) {
/* REST OF CODE OMITTED */
MyTimerTask myTask = new MyTimerTask();
myTimer = new Timer();
myTimer.schedule(myTask, 0, 10000);
}
/* REST OF CODE OMITTED */
private class MyTimerTask extends TimerTask {
public void run() {
if(!running){
Log.i("TAG", "NEW TIMER STARTED.");
RetrieveChatMessage task = new RetrieveChatMessage();
task.execute();
running = true;
}else{
running = false;
}
}
}
private class RetrieveChatMessage extends AsyncTask<String, Void, ArrayList<Chat>> {
#Override
protected ArrayList<Chat> doInBackground(String... params) {
// TODO Auto-generated method stub
ArrayList<Chat> cList = null;
String jResult = null;
Log.i("TAG", "RETRIEVING CHAT MESSAGE");
try {
jResult = ((new HttpRetriever())).getChatList(mAccount.email, mAccount.passwd);
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
if(jResult != null){
Log.i("TAG", "JSON DATA: " + jResult);
cList = (new ChatHandlers()).getChatList(jResult);
}else{
cList = null;
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
Log.e("TAG", "JSON Exception " + e.toString());
}
return cList;
}
#Override
protected void onPostExecute(final ArrayList<Chat> result) {
Log.i("TAG", "ON POST EXECUTE");
if(result != null){
// Do something here
}
}
}
To be honest the code above works with slight issues:
1. It seems to execute the Async randomly, instead of every 10 seconds.
2. When i go to another activity, somewhat it prevents other Async task from doing its job (Which is also trying to retrieve JSON response from server).
I am not too worried about the later problem (and that is not the question i am asking). I just would like to know how to have a proper timed Async Task. Can anyone point me to a direction.
Thank you.
EDIT #1:
after reading #thepoosh comment's i tried the following (i put it in onCreate):
scheduleTaskExecutor= Executors.newScheduledThreadPool(5);
scheduleTaskExecutor.scheduleAtFixedRate(new Runnable() {
public void run() {
// Parsing RSS feed:
// myFeedParser.doSomething();
Log.w("THUMBQOO", "NEW TASK STARTED");
retrieveChat();
}
}, 0, 15, TimeUnit.SECONDS);
Result: i have a consistent execution of Task. However, it seems that retrieveChat(); is never be called after the first execution.
Actually AsyncTask is not used for long operations .Check Here
You should use a Thread that uses a interface to notify UI or you can simply use a Handler which is the most Preffered way in android. Simply you can do a task repeatedly for every 10 seconds by
handler.postDelayed(new Runnable() {
#Override
public void run() {
// do work
handler.postDelayed(10000);
}
}, 10000);
Declare a Handler object to maintain future task executor...
private Handler mTimerHandler = new Handler();
Write a thread which will execute your future task...
private Runnable mTimerExecutor = new Runnable() {
#Override
public void run() {
//write your code what you want to do after the specified time elapsed
if(!running){
RetrieveChatMessage task = new RetrieveChatMessage();
task.execute();
running = true;
}else{
running = false;
}
}
};
Call your future tast executor with time using hanlder...
mTimerHandler.postDelayed(mTimerExecutor, 10000);
You can cancle your future task executor any time by this...
mTimerHandler.removeCallbacks(mTimerExecutor);
I am not sure if this is a very good way of accomplishing this (my answer here below) :
Use a Handler, create a HandlerThread and keep posting messages to this handler.
For the handlers "handleMessage" method, you can do your task and again send a message back to the MessageQueue.
HandlerThread thread = new HandlerThread(<name>);
thread.start();
Looper looper = thread.getLooper();
CustomHandler handler = new CustomHandler(looper);
// The CustomHandler class
class CustomHandler extends Handler {
public CustomHandler(Looper looper) {
super(looper);
}
#Override
public void handleMessage(Message msg) {
//Do your operation here
handler.sendEmptyMessageDelayed(msg, <delayTime>);
}
}

Android - Call an Asynctask from an Asynctask with infinity loop

I have 2 Asynctask, 1 for get data (location) from server then set a marker on map with this location and another call 1st Asyntask in a loop for updating location.
Here my code:
public class AsynComp extends AsyncTask<Void, Void, Void> {
ProgressDialog taxiDialog;
#Override
protected Void doInBackground(Void... params) {
jsonComp = new JSONComp(find_url);
find_status = jsonComp.getJsonStatus(txt_search);
return null;
}
#Override
protected void onPostExecute(Void result) {
super.onPostExecute(result);
if (find_status.equals("2013")) {
Toast.makeText(getBaseContext(), "no result",
Toast.LENGTH_SHORT).show();
} else if (find_status.equals("2012")) {
for (Marker marker:markers){
if(marker.getTitle().equals(compFollow)){
marker.remove();
}
}
for (int i=0; i<number;i++){
comp = new Comp(jsonComp.getJsondata(i));
SetMarkerComp(comp);
try {
Thread.sleep(1400);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
}
public class AsynFollow extends AsyncTask<Void, Void, Void> {
#Override
protected Void doInBackground(Void... params) {
if (!taxiFollow.equals("")) {
number = 1;
txt_search = compFollow;
find_url = "http://192.111.125.80:8001/Default.aspx?username="
+ Id + "&password=" + Pass + "&sohieuxe="+txt_search;
while (!stop){
new AsynComp().execute();
try {
Thread.sleep(1500);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
taxiFollow = "";
}
return null;
}
protected void onPostExecute(Void result) {
super.onPostExecute(result);
if (!compFollow.equals("")) {
Toast.makeText(getBaseContext(), "Follow "+compFollow, Toast.LENGTH_SHORT).show();
} else {
iv_theodoi.setVisibility(View.VISIBLE);
iv_theodoif.setVisibility(View.GONE);
Toast.makeText(getBaseContext(), "Plz choose a marker", Toast.LENGTH_SHORT).show();
}
}
}
And i have 2 buuton, 1 to call AsynFollow.execute(), another to stop it.
This code can run but app will force close after awhile.
Any solution? thanks.
P/s: i'm a newbie in android.
You shoulnd you asyncTask for this. For repetitive action, like changing status in some interval, use Timer class. In this way you can implement repetitive action which can be repeated in intervals.
In this way you can stop this time by on click listener. You can run two times and specify it's realtions using other variables.
If you're newbe, you should read about multitasking in Android: Timer, AsyncTask, Handler.
In my opinion this docs will tell you much more than thousands of comments in stackoverflow.

how to create a thread to refresh data in 3 second interval

I need a thread (it does httppost ,and parse the answer xml and refresh listview to set the changes from parsed xml) in 3 sec interval
I have already tried this code
Timer timer = new Timer();
timer.scheduleAtFixedRate(
new TimerTask() {
public void run() {
try {
httpPostList(url);
saxParseList();
list.invalidateViews();
Thread.sleep(1000);
} catch (Exception ie) {
}
}
}, 1000, 1000 * 30);
I would appreciate you to create a Service with an AsyncTask in it.
Async Tasks are the Android Synonym to normal Java Tasks, Documentation finding here: http://developer.android.com/reference/android/os/AsyncTask.html
Services are Background Processes, seeing this Doc:
http://developer.android.com/reference/android/app/Service.html
Try using handlers:
Handler handler;
#Override
public void onCreate(Bundle savedInstanceState) {
// ...
handler = new Handler() {
#Override
public void handleMessage(Message msg) {
updateUI();
}
};
Thread thread = new Thread() {
#Override
public void run() {
while(true) {
Message msg = new Message();
handler.sendMessage(msg);
try {
sleep(3*1000); // 3 seconds
} catch (InterruptedException e) {
}
}
}
};
thread.start();
}
private synchronized void updateUI() {
// ...
}
Finally I made it using "Async task".

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