public
abstract
class
TimerTask
extends Object
implements
Runnable
| java.lang.Object | |
| ↳ | java.util.TimerTask |
A task that can be scheduled for one-time or repeated execution by a Timer.
See also:
Protected constructors | |
|---|---|
TimerTask()
Creates a new timer task. |
|
Public methods | |
|---|---|
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. |
Inherited methods | |
|---|---|
 From
class
java.lang.Object
| |
From
interface
java.lang.Runnable
| |
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 | |
|---|---|
boolean |
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.) |
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:
Developers
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 | |
|---|---|
long |
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. |
See also: