Timers in Java

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I. Timers in Java

The 2 important classes to implement the timer function in Java are

• Timer class: Timer class, need an instance of TimerTask class as parameter;
• TimerTask: Timer task class, the task to be performed by the timer is defined in the Run method of the class.

Two. Two ways to implement a timer

1. Common implementations (as opposed to being implemented by internal classes)

1 //write a class first2  Public classTimetest {3  Public Static voidMain (string[] args) {4     5Timer timer =NewTimer ();6Timer.schedule (NewMyTask (), 1000,2000);7 }8 9 //and then write a class .Ten  Public classMyTaskextendstimertask{ One  A @Override -      Public voidrun () { -System.out.println ("Start Running");  the     } -}

2. Through the Inner class implementation

　　

1  PackageCom.lid;2 3 ImportJava.util.Calendar;4 Importjava.util.Date;5 ImportJava.util.Timer;6 ImportJava.util.TimerTask;7 8  Public classTest {9      Public Static voidMain (string[] args) {Ten         //timer1 (); One Timer2 (); A         //Timer3 (); -         //timer4 (); -     } the  -     //The first method: set the specified task tasks to execute schedule (timertask task, Date time) at specified times -      Public Static voidtimer1 () { -Timer timer =NewTimer (); +Timer.schedule (NewTimerTask () { -              Public voidrun () { +System.out.println ("-------set to specify task--------"); A             } at}, 2000);//sets the time specified, here is 2000 milliseconds -     } -  -     //The second method: Set the execution of a fixed delay peroid for the specified task tasks after specifying delay delays -     //Schedule (timertask task, long delay, long period) -      Public Static voidTimer2 () { inTimer timer =NewTimer (); -Timer.schedule (NewTimerTask () { to              Public voidrun () { +System.out.println ("-------set to specify task--------"); -             } the}, 1000, 1000); *     } $ Panax Notoginseng     //The third method: Set the execution of the fixed frequency peroid of the specified task tasks after specifying the delayed delay.  -     //scheduleatfixedrate (timertask task, long delay, long period) the      Public Static voidTimer3 () { +Timer timer =NewTimer (); ATimer.scheduleatfixedrate (NewTimerTask () { the              Public voidrun () { +System.out.println ("-------set to specify task--------"); -             } $}, 1000, 2000); $     } -     -     //Fourth method: Schedule the specified task to execute at a fixed rate period the specified time Firsttime begins to repeat.  the     //timer.scheduleatfixedrate (timertask task,date firsttime,long period) -      Public Static voidtimer4 () {WuyiCalendar Calendar =calendar.getinstance (); theCalendar.set (Calendar.hour_of_day, 12);//Control Time -Calendar.set (calendar.minute, 0);//Control Points WuCalendar.set (Calendar.second, 0);//Control seconds -  AboutDate time = Calendar.gettime ();//The time to execute the task, here is today's 12:00:00 $  -Timer timer =NewTimer (); -Timer.scheduleatfixedrate (NewTimerTask () { -              Public voidrun () { ASystem.out.println ("-------set to specify task--------"); +             } the}, time, 1000 * 60 * 60 * 24);//This setting will delay the execution of the daily fixed -     } $}

Timers in Java