In this tutorial we are going to see how you can use Timer and TimerTask classes of the java.util package in order to schedule the execution of a certain process.
The Timer class uses several flexible methods to make it possible to to schedule a task to be executed at a specific time, for once or for several times with intervals between executions.
To create your own schedulable processes, you have to create your own class the extends TimerTask class. TimerTask implements Runnable interface, so you have to override the run() method.
Let’s see the code :
package com.javacodegeeks.java.core;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;
public class TimerTaskExample extends TimerTask {
@Override
public void run() {
System.out.println("Start time:" + new Date());
doSomeWork();
System.out.println("End time:" + new Date());
}
// simulate a time consuming task
private void doSomeWork() {
try {
Thread.sleep(10000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
public static void main(String args[]) {
TimerTask timerTask = new TimerTaskExample();
// running timer task as daemon thread
Timer timer = new Timer(true);
timer.scheduleAtFixedRate(timerTask, 0, 10 * 1000);
System.out.println("TimerTask begins! :" + new Date());
// cancel after sometime
try {
Thread.sleep(20000);
} catch (InterruptedException e) {
e.printStackTrace();
}
timer.cancel();
System.out.println("TimerTask cancelled! :" + new Date());
try {
Thread.sleep(30000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}Output:
TimerTask begins! :Fri Jan 25 21:36:43 EET 2013
Start time:Fri Jan 25 21:36:43 EET 2013
End time:Fri Jan 25 21:36:53 EET 2013
Start time:Fri Jan 25 21:36:53 EET 2013
TimerTask cancelled! :Fri Jan 25 21:37:03 EET 2013
End time:Fri Jan 25 21:37:03 EET 2013Don’t forget take a careful look a the documentation of Timer and TimerTask to explore all the features of this mechanism.
This was a Java Timer and TimerTask Example.
