How to create/ schedule a Job or Thread to run at fixed intervals

Points To Remember

• TimerTask is a class that can run a Thread repeatedly after a specific period.
• You can either implement your own class also by implementing Runnable Interface.
• Then you may need to put your thread to sleep and then resume the thread after a desired interval.

The TimerTask will do this more efficiently for you then implementing your own code.

How to schedule a Thread to run after fixed interval

We will be using TimerTask to schedule the Thread after every 1 sec.

TimerTask class in Java implements Runnable interface and has the following methods.

• cancel - to cancel the timer task when needed.
• scheduledExecutionTime - gives the time when the task was last executed successfully.
• run - an abstract method that needs to be implemented.

MyTask.java

import java.util.TimerTask;
import java.util.Date;

class MyTask extends TimerTask {

 static int count = 0;
 
 @Override
 public void run(){
  if(count < 5){
     System.out.println(" MyTask called  ### count = "+ (++count));
  }
  else {
     cancel(); 
     System.out.println("#########    TASK CANCELLED    #######");
  }
 }

}

TestTimerTask.java

import java.util.TimerTask;
import java.util.Timer;

class TestTimerTask {

 public static void main(String args[]){

   TimerTask task = new MyTask();
   Timer timer = new Timer();
   timer.scheduleAtFixedRate(task,0,1000);

 }

}

 MyTask called  ### count = 1
 MyTask called  ### count = 2
 MyTask called  ### count = 3
 MyTask called  ### count = 4
 MyTask called  ### count = 5
#########    TASK CANCELLED    #######

So Thread goes on executing till it is stopped manually or till cancel() is called on the task.