How to set timer in android

Question

Can someone give a simple example of updating a textfield every second or so   I want to make a flying ball and need to calculate update the ball coordinates every second  that s why I need some sort of a timer   I don t get anything from here

User · Answer

I use this way   String   array           man   for   think     int j    then below the onCreate  TextView t   findViewById R id textView        new CountDownTimer 5000 1000              Override         public void onTick long millisUntilFinished               Override         public void onFinish                 t setText  I   array j     You                j                if j   array length-1  j 0              start                    start      it s easy way to solve this problem

User · Answer

You want your UI updates to happen in the already-existent UI thread   The best way is to use a Handler that uses postDelayed to run a Runnable after a delay  each run schedules the next   clear the callback with removeCallbacks   You re already looking in the right place  so look at it again  perhaps clarify why that code sample isn t what you want    See also the identical article at Updating the UI from a Timer

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Because this question is still attracting a lot of users from google search about Android timer  I would like to insert my two coins   First of all  the Timer class will be deprecated in Java 9  read the accepted answer     The official suggested way is to use ScheduledThreadPoolExecutor which is more effective and features-rich that can additionally schedule commands to run after a given delay  or to execute periodically  Plus it gives additional flexibility and capabilities of ThreadPoolExecutor   Here is an example of using plain functionalities    Create executor service   final ScheduledExecutorService SCHEDULER   Executors newScheduledThreadPool 1    Just schedule you runnable   final Future lt   gt  future   SCHEDULER schedule Runnable task  long delay TimeUnit unit    You can now use future to cancel the task or check if it is done for example   future isDone       Hope you will find this useful for creating a tasks in Android   Complete example   ScheduledExecutorService scheduler   Executors newScheduledThreadPool 1   Future lt   gt  sampleFutureTimer   scheduler schedule new Runnable    120  TimeUnit SECONDS   if  sampleFutureTimer isDone            Do something which will save world

User · Answer

I Abstract Timer away and made it a separate class      Timer java   import android os Handler   public class Timer        IAction action      Handler timerHandler   new Handler        int delayMS   1000       public Timer IAction action  int delayMS            this action   action          this delayMS   delayMS             public Timer IAction action            this action  1000              public Timer             this null              Runnable timerRunnable   new Runnable               Override         public void run                 if  action    null                  action Task                timerHandler postDelayed this  delayMS                         public void start             timerHandler postDelayed timerRunnable  0              public void stop             timerHandler removeCallbacks timerRunnable             And Extract main action from Timer class out as     IAction java   public interface IAction       void Task        And I used it just like this      MainActivity java   public class MainActivity extends Activity implements IAction      Timer timerClass   Override protected void onCreate Bundle savedInstanceState                        timerClass   new Timer this 1000           timerClass start                      int i   1   Override public void Task         runOnUiThread new Runnable               Override         public void run                 timer setText i                    i                                I Hope This Helps

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If you also need to run your code on UI thread  and not on timer thread   take a look on the blog  http   steve odyfamily com  p 12  public class myActivity extends Activity   private Timer myTimer       Called when the activity is first created      Override public void onCreate Bundle icicle        super onCreate icicle       setContentView R layout main        myTimer   new Timer        myTimer schedule new TimerTask                        Override         public void run                 TimerMethod                      0  1000      private void TimerMethod           This method is called directly by the timer       and runs in the same thread as the timer         We call the method that will work with the UI       through the runOnUiThread method      this runOnUiThread Timer Tick       private Runnable Timer Tick   new Runnable         public void run            This method runs in the same thread as the UI                        Do something to the UI thread here

User · Answer

If anyone is interested  I started playing around with creating a standard object to run on an activities UI thread   Seems to work ok   Comments welcome   I d love this to be available on the layout designer as a component to drag onto an Activity   Can t believe something like that doesn t already exist   package com example util timer   import java util Timer  import java util TimerTask   import android app Activity   public class ActivityTimer        private Activity m Activity      private boolean m Enabled      private Timer m Timer      private long m Delay      private long m Period      private ActivityTimerListener m Listener      private ActivityTimer  self      private boolean m FireOnce       public ActivityTimer             m Delay   0          m Period   100          m Listener   null          m FireOnce   false           self   this             public boolean isEnabled             return m Enabled             public void setEnabled boolean enabled            if  m Enabled    enabled              return              Disable any existing timer before we enable a new one         Disable             if  enabled                Enable                         private void Enable             if  m Enabled              return           m Enabled   true           m Timer   new Timer            if  m FireOnce                m Timer schedule new TimerTask                      Override                 public void run                         OnTick                                     m Delay             else               m Timer schedule new TimerTask                      Override                 public void run                         OnTick                                     m Delay  m Period                        private void Disable             if   m Enabled              return           m Enabled   false           if  m Timer    null              return           m Timer cancel            m Timer purge            m Timer   null             private void OnTick             if  m Activity    null  amp  amp  m Listener    null                m Activity runOnUiThread new Runnable                      Override                 public void run                         m Listener OnTimerTick m Activity   self                                                       if  m FireOnce              Disable               public long getDelay             return m Delay             public void setDelay long delay            m Delay   delay             public long getPeriod             return m Period             public void setPeriod long period            if  m Period    period              return          m Period   period             public Activity getActivity             return m Activity             public void setActivity Activity activity            if  m Activity    activity              return          m Activity   activity             public ActivityTimerListener getActionListener             return m Listener             public void setActionListener ActivityTimerListener listener            m Listener   listener             public void start             if  m Enabled              return          Enable               public boolean isFireOnlyOnce             return m FireOnce             public void setFireOnlyOnce boolean fireOnce            m FireOnce   fireOnce            In the activity  I have this onStart    Override protected void onStart         super onStart         m Timer   new ActivityTimer        m Timer setFireOnlyOnce true       m Timer setActivity this       m Timer setActionListener this       m Timer setDelay 3000       m Timer start

User · Answer

This is some simple code for a timer   Timer timer   new Timer    TimerTask t   new TimerTask                 Override     public void run              System out println  1             timer scheduleAtFixedRate t 1000 1000

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enter code here Thread th new Thread new Runnable              Override         public void run                 try   for int i 0 i lt 5 i                      b1 setText  quot  quot  i                   Thread sleep 5000                   runOnUiThread new Runnable                          Override                     public void run                             if  Build VERSION SDK INT  gt   Build VERSION CODES O           pp                                                                                               catch  InterruptedException e                    e printStackTrace                                        th start

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He re is simplier solution  works fine in my app     public class MyActivity extends Acitivity        TextView myTextView      boolean someCondition true         Override         protected void onCreate Bundle savedInstanceState                super onCreate savedInstanceState               setContentView R layout my activity                myTextView    TextView  findViewById R id refreshing field                  starting our task which update textview every 1000 ms             new RefreshTask   execute                        class which updates our textview every second      class RefreshTask extends AsyncTask                 Override             protected void onProgressUpdate Object    values                    super onProgressUpdate values                   String text   String valueOf System currentTimeMillis                     myTextView setText text                                Override             protected Object doInBackground Object    params                    while someCondition                        try                             sleep for 1s in background                            Thread sleep 1000                             and update textview in ui thread                         publishProgress                          catch  InterruptedException e                            e printStackTrace                                         return null

User · Answer

for whom wants to do this in kotlin  val timer   fixedRateTimer period   1000L                val currentTime  Date   Calendar getInstance   time             runOnUiThread                   tvFOO text   currentTime toString                            for stopping the timer you can use this  timer cancel    this function has many other options  give it a try

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void method boolean u int max        uu u      maxi max      if  uu  true                 CountDownTimer uy   new CountDownTimer maxi  1000                   public void onFinish                                 text setText  Finish                                 Override             public void onTick long l                    String currentTimeString DateFormat getTimeInstance   format new Date                     text setText currentTimeString                           start               else text setText  Stop

User · Answer

If one just want to schedule a countdown until a time in the future with regular notifications on intervals along the way  you can use the CountDownTimer class that is available since API level 1   new CountDownTimer 30000  1000        public void onTick long millisUntilFinished            editText setText  Seconds remaining      millisUntilFinished   1000              public void onFinish             editText setText  Done            start

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You can also use an animator for it   int secondsToRun   999   ValueAnimator timer   ValueAnimator ofInt secondsToRun   timer setDuration secondsToRun   1000  setInterpolator new LinearInterpolator     timer addUpdateListener new ValueAnimator AnimatorUpdateListener                  Override         public void onAnimationUpdate ValueAnimator animation                        int elapsedSeconds    int  animation getAnimatedValue                int minutes   elapsedSeconds   60              int seconds   elapsedSeconds   60               textView setText String format   d  02d   minutes  seconds                      timer start

User · Answer

I think you can do it in Rx way like     timerSubscribe   Observable interval 1  TimeUnit SECONDS               subscribeOn Schedulers io                 observeOn AndroidSchedulers mainThread                 subscribe new Action1 lt Long gt                       Override                 public void call Long aLong                            TODO do your stuff                                     And cancel this like   timerSubscribe unsubscribe      Rx Timer http   reactivex io documentation operators timer html

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For those who can t rely on Chronometer  I made a utility class out of one of the suggestions   public class TimerTextHelper implements Runnable      private final Handler handler   new Handler       private final TextView textView     private volatile long startTime     private volatile long elapsedTime      public TimerTextHelper TextView textView           this textView   textView            Override    public void run            long millis   System currentTimeMillis   - startTime         int seconds    int   millis   1000          int minutes   seconds   60         seconds   seconds   60          textView setText String format   d  02d   minutes  seconds            if  elapsedTime    -1               handler postDelayed this  500                     public void start            this startTime   System currentTimeMillis           this elapsedTime   -1         handler post this            public void stop            this elapsedTime   System currentTimeMillis   - startTime         handler removeCallbacks this            public long getElapsedTime            return elapsedTime            to use  just do    TimerTextHelper timerTextHelper   new TimerTextHelper textView    timerTextHelper start              timerTextHelper stop     long elapsedTime   timerTextHelper getElapsedTime

User · Answer

Here is a simple reliable way     Put the following code in your Activity  and the tick   method will be called every second in the UI thread while your activity is in the  resumed  state   Of course  you can change the tick   method to do what you want  or to be called more or less frequently    Override public void onPause          handler   null      super onPause       private Handler  handler    Override public void onResume         super onResume         handler   new Handler        Runnable r   new Runnable             public void run                 if   handler     h0                    tick                     handler postDelayed this  1000                                    private final Handler  h0    handler             r run       private void tick         System out println  Tick     System currentTimeMillis         For those interested  the   h0  handler  code is necessary to avoid two timers running simultaneously if your activity is paused and resumed within the tick period

User · Answer

It is simple  You create new timer      Timer timer   new Timer      Then you extend the timer task  class UpdateBallTask extends TimerTask      Ball myBall      public void run              calculate the new position of myBall          And then add the new task to the Timer with some update interval  final int FPS   40  TimerTask updateBall   new UpdateBallTask    timer scheduleAtFixedRate updateBall  0  1000 FPS     Disclaimer  This is not the ideal solution  This is solution using the Timer class  as asked by OP   In Android SDK  it is recommended to use the Handler class  there is example in the accepted answer

User · Answer

If you have delta time already   public class Timer       private float lastFrameChanged      private float frameDuration      private Runnable r       public Timer float frameDuration  Runnable r            this frameDuration   frameDuration          this lastFrameChanged   0          this r   r             public void update float dt            lastFrameChanged    dt           if  lastFrameChanged  gt  frameDuration                lastFrameChanged   0              r run

User · Answer

I m surprised that there is no answer that would mention solution with RxJava2  It is really simple and provides an easy way to setup timer in Android   First you need to setup Gradle dependency  if you didn t do so already   implementation  io reactivex rxjava2 rxjava 2 x y     replace x and y with current version number   Since we have just a simple  NON-REPEATING TASK  we can use Completable object   Completable timer 2  TimeUnit SECONDS  Schedulers computation             observeOn AndroidSchedulers mainThread             subscribe    - gt                   Timer finished  do something                  For REPEATING TASK  you can use Observable in a similar way   Observable interval 2  TimeUnit SECONDS  Schedulers computation             observeOn AndroidSchedulers mainThread             subscribe tick - gt                   called every 2 seconds  do something               throwable - gt                   handle error               Schedulers computation   ensures that our timer is running on background thread and  observeOn AndroidSchedulers mainThread    means code we run after timer finishes will be done on main thread   To avoid unwanted memory leaks  you should ensure to unsubscribe when Activity Fragment is destroyed

User · Answer

ok since this isn t cleared up yet there are 3 simple ways to handle this  Below is an example showing all 3 and at the bottom is an example showing just the method I believe is preferable   Also remember to clean up your tasks in onPause  saving state if necessary     import java util Timer  import java util TimerTask  import android app Activity  import android os Bundle  import android os Handler  import android os Message  import android os Handler Callback  import android view View  import android widget Button  import android widget TextView   public class main extends Activity       TextView text  text2  text3      long starttime   0        this  posts a message to the main thread from our timertask       and updates the textfield    final Handler h   new Handler new Callback               Override         public boolean handleMessage Message msg               long millis   System currentTimeMillis   - starttime             int seconds    int   millis   1000              int minutes   seconds   60             seconds       seconds   60              text setText String format   d  02d   minutes  seconds                return false                         runs without timer be reposting self    Handler h2   new Handler       Runnable run   new Runnable               Override         public void run                long millis   System currentTimeMillis   - starttime             int seconds    int   millis   1000              int minutes   seconds   60             seconds       seconds   60              text3 setText String format   d  02d   minutes  seconds                h2 postDelayed this  500                          tells handler to send a message    class firstTask extends TimerTask             Override         public void run                 h sendEmptyMessage 0                         tells activity to run on ui thread    class secondTask extends TimerTask             Override         public void run                 main this runOnUiThread new Runnable                       Override                 public void run                        long millis   System currentTimeMillis   - starttime                     int seconds    int   millis   1000                      int minutes   seconds   60                     seconds       seconds   60                      text2 setText String format   d  02d   minutes  seconds                                                           Timer timer   new Timer         Override     public void onCreate Bundle savedInstanceState            super onCreate savedInstanceState           setContentView R layout main            text    TextView findViewById R id text           text2    TextView findViewById R id text2           text3    TextView findViewById R id text3            Button b    Button findViewById R id button           b setText  start            b setOnClickListener new View OnClickListener                   Override             public void onClick View v                    Button b    Button v                  if b getText   equals  stop                         timer cancel                        timer purge                        h2 removeCallbacks run                       b setText  start                     else                      starttime   System currentTimeMillis                        timer   new Timer                        timer schedule new firstTask    0 500                       timer schedule new secondTask     0 500                       h2 postDelayed run  0                       b setText  stop                                                            Override     public void onPause             super onPause            timer cancel            timer purge            h2 removeCallbacks run           Button b    Button findViewById R id button           b setText  start                the main thing to remember is that the UI can only be modified from the main ui thread so use a handler or activity runOnUIThread Runnable r    Here is what I consider to be the preferred method     import android app Activity  import android os Bundle  import android os Handler  import android view View  import android widget Button  import android widget TextView   public class TestActivity extends Activity        TextView timerTextView      long startTime   0         runs without a timer by reposting this handler at the end of the runnable     Handler timerHandler   new Handler        Runnable timerRunnable   new Runnable               Override         public void run                 long millis   System currentTimeMillis   - startTime              int seconds    int   millis   1000               int minutes   seconds   60              seconds   seconds   60               timerTextView setText String format   d  02d   minutes  seconds                 timerHandler postDelayed this  500                          Override     public void onCreate Bundle savedInstanceState            super onCreate savedInstanceState           setContentView R layout test activity            timerTextView    TextView  findViewById R id timerTextView            Button b    Button  findViewById R id button           b setText  start            b setOnClickListener new View OnClickListener                   Override             public void onClick View v                    Button b    Button  v                  if  b getText   equals  stop                          timerHandler removeCallbacks timerRunnable                       b setText  start                      else                       startTime   System currentTimeMillis                        timerHandler postDelayed timerRunnable  0                       b setText  stop                                                          Override     public void onPause             super onPause            timerHandler removeCallbacks timerRunnable           Button b    Button findViewById R id button           b setText  start

User · Answer

import java text SimpleDateFormat  import java util Calendar  import java util Timer  import java util TimerTask   import android os Bundle  import android view View  import android view View OnClickListener  import android widget Button  import android widget CheckBox  import android widget TextView  import android app Activity   public class MainActivity extends Activity     CheckBox optSingleShot   Button btnStart  btnCancel   TextView textCounter    Timer timer   MyTimerTask myTimerTask     Override  protected void onCreate Bundle savedInstanceState      super onCreate savedInstanceState     setContentView R layout activity main     optSingleShot    CheckBox findViewById R id singleshot     btnStart    Button findViewById R id start     btnCancel    Button findViewById R id cancel     textCounter    TextView findViewById R id counter      btnStart setOnClickListener new OnClickListener         Override    public void onClick View arg0         if timer    null        timer cancel                 re-schedule timer here       otherwise  IllegalStateException of        TimerTask is scheduled already         will be thrown     timer   new Timer        myTimerTask   new MyTimerTask         if optSingleShot isChecked            singleshot delay 1000 ms      timer schedule myTimerTask  1000        else         delay 1000ms  repeat in 5000ms      timer schedule myTimerTask  1000  5000                    btnCancel setOnClickListener new OnClickListener         Override    public void onClick View v        if  timer  null        timer cancel         timer   null                         class MyTimerTask extends TimerTask       Override   public void run        Calendar calendar   Calendar getInstance       SimpleDateFormat simpleDateFormat         new SimpleDateFormat  dd MMMM yyyy HH mm ss a       final String strDate   simpleDateFormat format calendar getTime         runOnUiThread new Runnable          Override     public void run          textCounter setText strDate                          xml    lt LinearLayout xmlns android  http   schemas android com apk res android  xmlns tools  http   schemas android com tools  android layout width  match parent  android layout height  match parent  android paddingBottom   dimen activity vertical margin  android paddingLeft   dimen activity horizontal margin  android paddingRight   dimen activity horizontal margin  android paddingTop   dimen activity vertical margin  android orientation  vertical  tools context   MainActivity   gt    lt TextView     android layout width  wrap content      android layout height  wrap content      android layout gravity  center horizontal      android autoLink  web      android text  http   android-er blogspot com       android textStyle  bold    gt   lt CheckBox      android id    id singleshot      android layout width  wrap content      android layout height  wrap content      android text  Single Shot   gt

User · Answer

You need to create a thread to handle the update loop and use it to update the textarea   The tricky part though is that only the main thread can actually modify the ui so the update loop thread needs to signal the main thread to do the update   This is done using a Handler   Check out this link  http   developer android com guide topics ui dialogs html  Click on the section titled  Example ProgressDialog with a second thread    It s an example of exactly what you need to do  except with a progress dialog instead of a textfield

[android] How to set timer in android?

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