job scheduler in android N with less then 15 minutes interval

问题

Part of my question, how I can set up a job with less then 15 minutes interval in "Nougat", was answerd by "blizzard" in his answer here:
Job Scheduler not running on Android N
He explained the problem and suggested to use the following workaround:

JobInfo jobInfo;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
  jobInfo = new JobInfo.Builder(JOB_ID, serviceName)
      .setMinimumLatency(REFRESH_INTERVAL)
      .setExtras(bundle).build();
} else {
  jobInfo = new JobInfo.Builder(JOB_ID, serviceName)
      .setPeriodic(REFRESH_INTERVAL)
      .setExtras(bundle).build();
}

However, using the suggested

  .setMinimumLatency(REFRESH_INTERVAL)

just starts the job once;
but how do I get it periodic with a period of around 30 seconds on an android nougat device (not using handler or alarm manager)?

回答1:

If someone is still trying to overcome the situation,

Here is a workaround for >= Android N (If you want to set the periodic job lower than 15 minutes)

Check that only setMinimumLatency is used. Also, If you are running a task that takes a long time, the next job will be scheduled at, Current JOB Finish time + PROVIDED_TIME_INTERVAL

.SetPeriodic(long millis) works well for API Level below Android N

@Override
public boolean onStartJob(final JobParameters jobParameters) {
    Log.d(TAG,"Running service now..");
    //Small or Long Running task with callback

    //Reschedule the Service before calling job finished
    if(android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.N)
              scheduleRefresh();

    //Call Job Finished
    jobFinished(jobParameters, false );

    return true;
}

@Override
public boolean onStopJob(JobParameters jobParameters) {
    return false;
}

private void scheduleRefresh() {
  JobScheduler mJobScheduler = (JobScheduler)getApplicationContext()
                    .getSystemService(JOB_SCHEDULER_SERVICE);
  JobInfo.Builder mJobBuilder = 
  new JobInfo.Builder(YOUR_JOB_ID,
                    new ComponentName(getPackageName(), 
                    GetSessionService.class.getName()));

  /* For Android N and Upper Versions */
  if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
      mJobBuilder
                .setMinimumLatency(60*1000) //YOUR_TIME_INTERVAL
                .setRequiredNetworkType(JobInfo.NETWORK_TYPE_ANY);
  }

UPDATE: If you are considering your repeating job to run while in Doze Mode and thinking about JobScheduler, FYI: JobSchedulers are not allowed to run in Doze mode.

I have not discussed about the Dozing because we were talking about JobScheduler. Thanks, @Elletlar, for pointing out that some may think that it will run even when the app is in doze mode which is not the case.

For doze mode, AlarmManager still gives the best solution. You can use setExactAndAllowWhileIdle() if you want to run your periodic job at exact time period or use setAndAllowWhileIdle() if you're flexible.

You can also user setAlarmClock() as device always comes out from doze mode for alarm clock and returns to doze mode again. Another way is to use FCM.

Reference: Doze Restrictions

https://developer.android.com/training/monitoring-device-state/doze-standby

回答2:

I struggled with same thing when I wanted to setup Job for refresh small part of data. I found out that solution for this problem may be setting up Job one more time with the same ID after i calledjobFinished(JobParameters, boolean). I think it should work every time on main thread.

My function to setup Job looks like this:

JobInfo generateRefreshTokenJobInfo(long periodTime){
    JobInfo.Builder jobBuilder = new JobInfo.Builder(1L, new ComponentName(mContext, JobService.class));
    jobBuilder.setMinimumLatency(periodTime);
    jobBuilder.setOverrideDeadline((long)(periodTime * 1.05));
    jobBuilder.setRequiresDeviceIdle(false);
    return jobBuilder.build();
}

When I finish my work after first call of Job i call in main thread

jobFinished(mJobParameters, true);
registerRefreshJob(5*60*1000L);

This will reschedule my Job one more time for the same amount of time on the same id. When device is in idle state you still have to take under consideration lack of wake locks in doze so your job may not be started so often as you wish. It is mentioned in https://developer.android.com/about/versions/nougat/android-7.0-changes.html

If the device is stationary for a certain time after entering Doze, the system applies the rest of the Doze restrictions to PowerManager.WakeLock, AlarmManager alarms, GPS, and Wi-Fi scans. Regardless of whether some or all Doze restrictions are being applied, the system wakes the device for brief maintenance windows, during which applications are allowed network access and can execute any deferred jobs/syncs.

来源：https://stackoverflow.com/questions/39641278/job-scheduler-in-android-n-with-less-then-15-minutes-interval

标签

android

job-scheduling

android-7.0-nougat