org.jboss.util

Class TimerTask

java.lang.Object

org.jboss.util.TimerTask

All Implemented Interfaces:

java.lang.Comparable, Executable

public abstract class TimerTask
extends java.lang.Object
implements Executable, java.lang.Comparable

A class that represent a task that can be scheduled for one-shot or repeated execution by a TimerQueue.

A similar class is present in java.util package of jdk version >= 1.3; for compatibility with jdk 1.2 we reimplemented it.

Version:

$Revision$

See Also:

TimerQueue

Field Summary

Fields

Modifier and Type	Field and Description
(package private) static int	CANCELLED The state when cancelled
(package private) static int	EXECUTED The state after first execution if the TimerTask is not repeating
private java.lang.Object	m_lock
private long	m_nextExecutionTime
private long	m_period
private int	m_state
(package private) static int	NEW The state before the first execution
(package private) static int	SCHEDULED The state after first execution if the TimerTask is repeating

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	TimerTask() Creates a TimerTask object that will be executed once.
protected	TimerTask(long period) Creates a TimerTask object that will be executed every period milliseconds.

Method Summary

Modifier and Type	Method and Description
boolean	cancel() Cancels the next execution of this TimerTask (if any).
int	compareTo(java.lang.Object other) A TimerTask is less than another if it will be scheduled before.
abstract void	execute() The task to be executed, to be implemented in subclasses.
(package private) java.lang.Object	getLock() Returns the mutex that syncs the access to this object
(package private) long	getNextExecutionTime() Returns the next execution time for this TimerTask
protected long	getPeriod()
(package private) int	getState() Returns the state of execution of this TimerTask
(package private) boolean	isPeriodic() Returns whether this TimerTask is periodic
(package private) void	setNextExecutionTime(long time) Sets the next execution time for this TimerTask
(package private) void	setState(int state) Sets the state of execution of this TimerTask

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

NEW

static final int NEW

The state before the first execution

See Also:

Constant Field Values

SCHEDULED

static final int SCHEDULED

The state after first execution if the TimerTask is repeating

See Also:

Constant Field Values

EXECUTED

static final int EXECUTED

The state after first execution if the TimerTask is not repeating

See Also:

Constant Field Values

CANCELLED

static final int CANCELLED

The state when cancelled

See Also:

Constant Field Values

m_lock

private final java.lang.Object m_lock

m_state

private int m_state

m_period

private final long m_period

m_nextExecutionTime

private long m_nextExecutionTime

Constructor Detail

TimerTask

protected TimerTask()

Creates a TimerTask object that will be executed once.

TimerTask

protected TimerTask(long period)

Creates a TimerTask object that will be executed every period milliseconds.

Parameters:

period - the execution period; if zero, will be executed only once.

Method Detail

cancel

public boolean cancel()

Cancels the next execution of this TimerTask (if any).
If the TimerTask is executing it will prevent the next execution (if any).

Returns:

true if one or more scheduled execution will not take place, false otherwise.

execute

public abstract void execute()
                      throws java.lang.Exception

The task to be executed, to be implemented in subclasses.

Specified by:

execute in interface Executable

Throws:

java.lang.Exception

compareTo

public int compareTo(java.lang.Object other)

A TimerTask is less than another if it will be scheduled before.

Specified by:

compareTo in interface java.lang.Comparable

Throws:

java.lang.ClassCastException - if other is not a TimerTask, according to the Comparable contract

getLock

java.lang.Object getLock()

Returns the mutex that syncs the access to this object

setState

void setState(int state)

Sets the state of execution of this TimerTask

getState

int getState()

Returns the state of execution of this TimerTask

isPeriodic

boolean isPeriodic()

Returns whether this TimerTask is periodic

getNextExecutionTime

long getNextExecutionTime()

Returns the next execution time for this TimerTask

setNextExecutionTime

void setNextExecutionTime(long time)

Sets the next execution time for this TimerTask

getPeriod

protected long getPeriod()

Returns:

the period of this TimerTask