Create a Scheduled service in android

问题

I need to create a schedule service in android with java. I have tried some codes , but all time after build the application it doesn't run. My logic is simple , I want to make a service to check the existence of a file in the bluetooth folder path, If this file is there , so this service will run another application , I need this with a schedule which run every 2 minutes.

Until now that's great, but now I have an error The method startActivity(Intent) is undefined for the type MyTimerTask. I have tried this code...

public class MyTimerTask extends TimerTask {
    java.io.File file = new java.io.File("/mnt/sdcard/Bluetooth/1.txt");

    public void run(){ 
        if (file.exists()) {
            Intent intent = new Intent(Intent.ACTION_MAIN);
            intent.setComponent(new ComponentName("com.package.address","com.package.address.MainActivity"));
            startActivity(intent);
        }
    } 
}

Could someone please help me with this.

回答1:

There are two ways to achieve your requirement.

TimerTask

Alarm Manager Class

TimerTask has a method that repeats the activity on the given particular time interval. look at the following sample example.

Timer timer; 
MyTimerTask timerTask; 

timer = new Timer(); 
timerTask = new MyTimerTask();
timer.schedule ( timerTask, startingInterval, repeatingInterval );

private class MyTimerTask extends TimerTask 
{
     public void run()
     { 
        ...
        // Repetitive Activity goes here
     } 
}

AlarmManager does same thing like TimerTask but as it occupies lesser memory to execute tasks.

public class AlarmReceiver extends BroadcastReceiver 
{
    @Override
    public void onReceive(Context context, Intent intent) 
    {
        try 
        {
            Bundle bundle = intent.getExtras();
            String message = bundle.getString("alarm_message");
            Toast.makeText(context, message, Toast.LENGTH_SHORT).show();
        } 
        catch (Exception e) 
        {
             Toast.makeText(context, "There was an error somewhere, but we still received an alarm", Toast.LENGTH_SHORT).show();
 e.printStackTrace();
        }
   }
}

AlarmClass,

private static Intent alarmIntent = null;
private static PendingIntent pendingIntent = null;
private static AlarmManager alarmManager = null;

    // OnCreate()
    alarmIntent = new Intent ( null, AlarmReceiver.class );
    pendingIntent = PendingIntent.getBroadcast( this.getApplicationContext(), 234324243, alarmIntent, 0 );
alarmManager = ( AlarmManager ) getSystemService( ALARM_SERVICE );
    alarmManager.setRepeating( AlarmManager.RTC_WAKEUP, ( uploadInterval * 1000 ),( uploadInterval * 1000 ), pendingIntent );

来源：https://stackoverflow.com/questions/12188434/create-a-scheduled-service-in-android

标签

java

android

service

bluetooth

schedule