java.util

Class TimerTask

Implemented Interfaces:
Runnable
Known Direct Subclasses:
DelegatingTimerTask

public abstract class TimerTask
extends Object
implements Runnable

A task that can be scheduled for one-time or repeated execution by a Timer.
Since:
1.3
See Also:
Timer

Constructor Summary

TimerTask()
Creates a new timer task.

Method Summary

boolean
cancel()
Cancels this timer task.
abstract void
run()
The action to be performed by this timer task.
long
scheduledExecutionTime()
Returns the scheduled execution time of the most recent actual execution of this task.

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

TimerTask

protected TimerTask()
Creates a new timer task.

Method Details

cancel

public boolean cancel()
Cancels this timer task. If the task has been scheduled for one-time execution and has not yet run, or has not yet been scheduled, it will never run. If the task has been scheduled for repeated execution, it will never run again. (If the task is running when this call occurs, the task will run to completion, but will never run again.)

Note that calling this method from within the run method of a repeating timer task absolutely guarantees that the timer task will not run again.

This method may be called repeatedly; the second and subsequent calls have no effect.

Returns:
true if this task is scheduled for one-time execution and has not yet run, or this task is scheduled for repeated execution. Returns false if the task was scheduled for one-time execution and has already run, or if the task was never scheduled, or if the task was already cancelled. (Loosely speaking, this method returns true if it prevents one or more scheduled executions from taking place.)
Usages and Demos :

View More Examples of cancel()
   1: import java.awt.event.MouseEvent;
   2: import java.util.TimerTask;
   3: 
   4:         ...
   5: 
   6:   TimerTask tt;
   7: 
   8:         ...
   9: 
  10:         tt = new TimerTask() { public void run() { go(); } };
  11:         getGlobal().getTimer().schedule(tt, Integers.parseInt(getAttr(ATTR_DELAY), 5000));
  12:         ...
  13:   public void go() {
  14:     tt.cancel();

View Full Code Here
   1: 
   2: import java.util.TimerTask;
   3: 
   4:         ...
   5: 
   6:     private TimerTask task;
   7: 
   8:         ...
   9: 
  10:     public TimerTask getTimerTask() {
  11:         System.out.println("Timeout " + this + " for " + connection + "activated.");
  12:         ...
  13:        System.out.println("Timeout " + this + "  for " + connection + "deactivated.");
  14:        task.cancel();

View Full Code Here
   1: 
   2: import java.util.TimerTask;
   3: 
   4:         ...
   5: abstract public class IntervalDaemon extends DefaultDaemon {
   6:     TimerTask timerTaskDelegator;
   7:      long INITIAL_DELAY_MILLIS = 30000L;
   8:         ...
   9:         }
  10:         timerTaskDelegator.cancel();
  11:         timerTaskDelegator = null;
  12:         ...
  13: 
  14:     private class TimerTaskDelegator extends TimerTask {

View Full Code Here
   1: import java.util.Timer;
   2: import java.util.TimerTask;
   3: 
   4:         ...
   5:     
   6:     static synchronized void schedule(TimerTask task, long delay, long period) {
   7:         if (null == _timer) {
   8:         ...
   9:     
  10:     static synchronized void cancel(TimerTask task) {
  11:         ...
  12:         task.cancel();

View Full Code Here
   1: import java.util.Timer;
   2: import java.util.TimerTask;
   3: 
   4:         ...
   5:   private static class TimerTaskAdapter
   6:     extends TimerTask
   7:   {
   8:         ...
   9:       throw new IllegalStateException("already scheduled");
  10:     TimerTask timerTask = new TimerTaskAdapter(command);
  11:     timerTaskMap.put(command, timerTask);
  12:         ...
  13:       throw new IllegalStateException("not scheduled");
  14:     timerTask.cancel();

View Full Code Here

run

public abstract void run()
The action to be performed by this timer task.
Specified by:
run in interface Runnable
Usages and Demos :

View More Examples of run()
   1: import java.util.Timer;
   2: import java.util.TimerTask;
   3: 
   4:         ...
   5:         mittfb.afterPropertiesSet();
   6:         final TimerTask timerTask1 = (TimerTask) mittfb.getObject();
   7: 
   8:         ...
   9:             assertTrue(timerFactoryBean.getObject() instanceof Timer);
  10:             timerTask0.run();
  11:         ...
  12:             timerTask1.run();

View Full Code Here
   1: import java.util.Enumeration;
   2: import java.util.TimerTask;
   3: 
   4:         ...
   5: 
   6:     public void addTask (TimerTask task) {
   7:     synchronized (tasks) {
   8:         ...
   9: 
  10:     public void removeTask (TimerTask task) {
  11:     synchronized (tasks) {
  12:         ...
  13:         TimerTask task = (TimerTask) tasks.elementAt(i);
  14:         task.run();

View Full Code Here
   1: import java.util.Timer;
   2: import java.util.TimerTask;
   3: 
   4:         ...
   5: 
   6:         final TimerTask task = new TimerTask() {
   7:             String lastText = "";
   8:         ...
   9:                     lbl.setText("");
  10:                 task.run();
  11:             }
  12:         ...
  13:                 btnRefresh.setData("Pressing", "1");
  14:                 task.run();

View Full Code Here
   1: import java.util.Date;
   2: import java.util.TimerTask;
   3: 
   4:         ...
   5:     
   6:     private TimerTask _task = null;
   7:     
   8:         ...
   9:         cancel();
  10:         _task.run();
  11:     }
  12:         ...
  13:     
  14:     public final TimerTask getTimerTask()

View Full Code Here
   1: import java.util.Iterator;
   2: import java.util.TimerTask;
   3: 
   4:         ...
   5:     private String passiveSessionKey = null;
   6:     private TimerTask pullTask = new TimerTask() {
   7:         public synchronized void run()
   8:         ...
   9:         requestPassiveSession();
  10:         pullTask.run();
  11:       }

View Full Code Here

scheduledExecutionTime

public long scheduledExecutionTime()
Returns the scheduled execution time of the most recent actual execution of this task. (If this method is invoked while task execution is in progress, the return value is the scheduled execution time of the ongoing task execution.)

This method is typically invoked from within a task's run method, to determine whether the current execution of the task is sufficiently timely to warrant performing the scheduled activity:

   public void run() {
       if (System.currentTimeMillis() - scheduledExecutionTime() >=
           MAX_TARDINESS)
               return;  // Too late; skip this execution.
       // Perform the task
   }
 
This method is typically not used in conjunction with fixed-delay execution repeating tasks, as their scheduled execution times are allowed to drift over time, and so are not terribly significant.
Returns:
the time at which the most recent execution of this task was scheduled to occur, in the format returned by Date.getTime(). The return value is undefined if the task has yet to commence its first execution.