Timer Task stops running after indefinite time in android

问题

I am a newbie in android. I am developing an app in which a particular piece of code executes after every 5 seconds in background.To achieve this I am using a service with timer with a timer task in it. For sometime its working fine but after some indefinite my service is running but timer task stops automatically in android. Here is my code please help. Thanks in advance.

    public void onStart(Intent intent, int startid) {
    //this is the code for my onStart in service class
    int delay = 1000; // delay for 1 sec.

    final int period = 5000; // repeat 5 sec.

    timer = new Timer();
    timer.schedule(new TimerTask() {
        @Override
        public void run() {
                        executeCode();
    }, delay, period);

};

回答1:

In my opinion, you should use AlarmManager with an IntentService to schedule repeating background tasks instead of Timer tasks. A Timer is unreliable and doesn't always work correctly within the Android Framework. Also, a Timer won't execute if the phone is asleep. You can have alarms wake up the phone to execute your code with AlarmManager.

See:

https://developer.android.com/reference/android/app/AlarmManager.html

http://mobile.tutsplus.com/tutorials/android/android-fundamentals-scheduling-recurring-tasks/

http://android-er.blogspot.in/2010/10/simple-example-of-alarm-service-using.html

In case of phone restart, you will need to trigger the alarm manager again. See this tutorial for exact instructions on how to do this:

http://www.androidenea.com/2009/09/starting-android-service-after-boot.html

回答2:

Generally TimerTask stops when device goes to sleep mode for long time. Try to use AlarmManager class for your requirement. AlarmManager uses lesser battery consumption too.

Here is an example, how to use AlarmManager

回答3:

I guess you can attain this task better if you use CountDown Timer which has an inbuilt method which is called after time you have specified

Example

public class CountDownTest extends Activity {
TextView tv; //textview to display the countdown
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
tv = new TextView(this);
this.setContentView(tv);
//5000 is the starting number (in milliseconds)
//1000 is the number to count down each time (in milliseconds)
MyCount counter = new MyCount(5000,1000);
counter.start();
}
//countdowntimer is an abstract class, so extend it and fill in methods
public class MyCount extends CountDownTimer{
public MyCount(long millisInFuture, long countDownInterval) {
super(millisInFuture, countDownInterval);
}
@Override
public void onFinish() {
tv.setText(”done!”);
}
@Override
public void onTick(long millisUntilFinished) {
tv.setText(”Left: ” + millisUntilFinished/1000);
}
}

Edit
you can perform any function in OnTick method which will be called in every 1000 millisecond in above example

Learn more about it here

来源：https://stackoverflow.com/questions/13158163/timer-task-stops-running-after-indefinite-time-in-android