Java Timer purge() Method

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Description

The Java Timer purge() method is used to remove all cancelled tasks from this timer's task queue.

Declaration

Following is the declaration for java.util.Timer.purge() method.

public int purge()

Parameters

NA

Return Value

The method call returns the number of tasks removed from the queue.

Exception

NA

Purging a Timer Scheduled at Fixed Rate Example

The following example shows the usage of Java Timer purge() method to purge the timer operations currently scheduled. We've created a timer object using a CustomTimerTask object. CustomTimerTask is custom class extending TimerTask class and implements the run() method which will execute at scheduled time. Then we created a timer object and scheduled a task using scheduleAtFixedRate() to execute at every 100 milliseconds starting from now. Then using cancel() method, the timer operation is terminated and using purge() method, cancelled task is removed from the queue.

package com.tutorialspoint;

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

public class TimerDemo {
   public static void main(String[] args) {

      // creating timer task, timer
      TimerTask tasknew = new CustomTimerTask();
      Timer timer = new Timer();

      // scheduling the task
      timer.scheduleAtFixedRate(tasknew, new Date(), 100);

      // terminating the timer
      System.out.println("cancelling timer");
      timer.cancel();
      System.out.println("purge value :"+timer.purge());
   }
}

class CustomTimerTask extends TimerTask {

   @Override
   public void run() {
      System.out.println("working on");
   }  
}

Output

Let us compile and run the above program, this will produce the following result.

cancelling timer
purge value :0
working on

Purging a Timer Scheduled at Fixed Rate and Date Example

The following example shows the usage of Java Timer purge() method to purge the timer operations currently scheduled. We've created a timer object using a CustomTimerTask object. CustomTimerTask is custom class extending TimerTask class and implements the run() method which will execute at scheduled time. Then we created a timer object as a daemon thread and scheduled a task using scheduleAtFixedRate() to execute at every 100 milliseconds starting from now. Then using cancel() method, the timer operation is terminated and using purge() method, cancelled task is removed from the queue.

package com.tutorialspoint;

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

public class TimerDemo {
   public static void main(String[] args) {

      // creating timer task, timer
      TimerTask tasknew = new CustomTimerTask();
      Timer timer = new Timer(true);

      // scheduling the task
      timer.scheduleAtFixedRate(tasknew, new Date(), 100);

      // terminating the timer
      System.out.println("cancelling timer");
      timer.cancel();
      System.out.println("purge value :"+timer.purge());
   }
}

class CustomTimerTask extends TimerTask {

   @Override
   public void run() {
      System.out.println("working on");
   }  
}

Output

Let us compile and run the above program, this will produce the following result.

cancelling timer
purge value :0
working on

Purging a Timer Scheduled at Fixed Date and Initial Delay Example

The following example shows the usage of Java Timer purge() method to purge the timer operations currently scheduled. We've created a timer object using a CustomTimerTask object. CustomTimerTask is custom class extending TimerTask class and implements the run() method which will execute at scheduled time. Then we created a timer object as a daemon thread, with a given name and scheduled a task using scheduleAtFixedRate() to execute at every 100 milliseconds starting from now. Then using cancel() method, the timer operation is terminated and using purge() method, cancelled task is removed from the queue.

package com.tutorialspoint;

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

public class TimerDemo {
   public static void main(String[] args) {

      // creating timer task, timer
      TimerTask tasknew = new CustomTimerTask();
      Timer timer = new Timer("test",true);

      // scheduling the task
      timer.scheduleAtFixedRate(tasknew, new Date(), 100);

      // terminating the timer
      System.out.println("cancelling timer");
      timer.cancel();
      System.out.println("purge value :"+timer.purge());
   }
}

class CustomTimerTask extends TimerTask {

   @Override
   public void run() {
      System.out.println("working on");
   }  
}

Output

Let us compile and run the above program, this will produce the following result.

cancelling timer
purge value :0
working on