在x分钟后做某事，然后每n分钟再做一次

Question

I need to show an ad when a user visits a particular screen at or after 2 mins, then whenever they visit again after 6 minutes,10,14,16...

I have the code below, it works fine if the user visits the screen at minutes 2,6,10,14 etc however it does not work if the user misses these minutes. for example if an ad was shown at minute 2 but the user didn't come back until minute 8, the ad for minute 6 is missed.

How can I cater for this with what i have so that if the user comes back outside of these minutes, the ad for them will still be shown?

long start = adStartTime;
long now = new Date().getTime();
int minsElapsedSinceLastAd = (int) ((now - start) / 1000 / 60);
showAd = previousRunMin !=minsElapsedSinceLastAd&& minsElapsedSinceLastAd % 4 == 2;
if (showAd) {
   showAd();
   ...
   previousRunMin = minsElapsedSinceLastAd;

}

previousRunMin is there so that if the user comes back on the same minute, the ad is not shown

Answer 1

Consider using a ScheduledThreadPoolExecutor with scheduleAtFixedRate : The call described here: ScheduledExecutorService#scheduleAtFixedRate(Runnable command, long initialDelay, long period, TimeUnit unit) does as you ask, scheduling an activity in a separate thread with a specified delay and period. Perhaps I could be more specific to your application but the code snippet included in your question doesn't give sufficient context to understand how the activity being scheduled works.

Answer 2

I am not sure exactly what the code before your segment is... I'll assume it's in some sort of loop.

Either way, you can do the easiest way you know how. If and when showAd is true set a global boolean to be true. Then base the add showing off that new boolean. Also another major issue is there is no check to see if the user actually saw the ad...

It would be so much easier if there was a check to see if the ad was seen. If you do not have a check then it would be pretty hard to know.