Experiments of Timer.scheduleatfixedrate and Timer.schedule

Base code:

Calendar currenttime = Calendar.getinstance ();

Currenttime.settime (New Date ());

int currenthour = Currenttime.get (Calendar.second);

Currenttime.set (Calendar.second, Currenthour + 20);//First (greater than 20 seconds): Currenthour + 20; second (less than 20 seconds): Currenthour- 20; third (equals current): Currenthour
Currenttime.set (Calendar.millisecond, 0);

Date nexthour = Currenttime.gettime ();

Explain:

Nexthour

1*60*1000: one-minute cycle

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1. Experiments with Timer.scheduleatfixedrate (task, firsttime, period)

Timer.scheduleatfixedrate (New Myhouronlinetask (Event.getservletcontext ()), nexthour,1*60*1000);

Experimental results:

Hypothetical condition: The time after project start OK is 2015-01-08 10:00:00!

First: 2015-01-08 10:00:20 when the scheduled task executes once, and then starts from 2015-01-08 10:00:20, every 1 minutes.

Second: 2015-01-08 10:00:00 the scheduled task executes once, and then starts from 2015-01-08 10:00:40, and executes every 1 minutes.

Third: 2015-01-08 10:00:00 when the scheduled task executes once, every 1 minutes.

Remark Timer.scheduleatfixedrate (New Myhouronlinetask (Event.getservletcontext ()), 0,1*60*1000); 2015-01-08 10:00:00 timed tasks are executed once, every 1 minutes.

2. Experiments with Timer.schedule (task, firsttime, period)

Experimental results:

Hypothetical condition: The time after project start OK is 2015-01-08 10:00:00!

First: 2015-01-08 10:00:20 when the scheduled task executes once, and then starts from 2015-01-08 10:00:20, every 1 minutes.

Second: 2015-01-08 10:00:00 the scheduled task executes once, every 1 minutes.

Third: 2015-01-08 10:00:00 when the scheduled task executes once, every 1 minutes.

Note Timer.schedule (New Myhouronlinetask (Event.getservletcontext ()), 0,1*60*1000); when, 2015-01-08 10:00:00 the scheduled task executes once, Executes every 1 minutes.

Experiments of Timer.scheduleatfixedrate and Timer.schedule