/*
* Copyright 2002-2007 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.scheduling.timer;
import java.util.TimerTask;
/**
* JavaBean that describes a scheduled {@link TimerTask}, consisting of the
* {@link TimerTask} itself or a {@link Runnable} to create a {@link TimerTask}
* for and a delay plus period. The period needs to be specified; there is
* no point in a default for it.
*
* <p>The JDK's {@link java.util.Timer} facility does not offer sophisticated
* scheduling options such as cron expressions. Consider using Quartz for
* such advanced needs.
*
* <p>Note that the {@link java.util.Timer} mechanism uses a {@link TimerTask}
* instance that is shared between repeated executions, in contrast to Quartz
* which creates a new Job instance for each execution.
*
* @author Juergen Hoeller
* @since 19.02.2004
* @see java.util.TimerTask
* @see java.util.Timer#schedule(TimerTask, long, long)
* @see java.util.Timer#scheduleAtFixedRate(TimerTask, long, long)
*/
public class ScheduledTimerTask {
private TimerTask timerTask;
private long delay = 0;
private long period = -1;
private boolean fixedRate = false;
/**
* Create a new ScheduledTimerTask,
* to be populated via bean properties.
* @see #setTimerTask
* @see #setDelay
* @see #setPeriod
* @see #setFixedRate
*/
public ScheduledTimerTask() {
}
/**
* Create a new ScheduledTimerTask, with default
* one-time execution without delay.
* @param timerTask the TimerTask to schedule
*/
public ScheduledTimerTask(TimerTask timerTask) {
this.timerTask = timerTask;
}
/**
* Create a new ScheduledTimerTask, with default
* one-time execution with the given delay.
* @param timerTask the TimerTask to schedule
* @param delay the delay before starting the task for the first time (ms)
*/
public ScheduledTimerTask(TimerTask timerTask, long delay) {
this.timerTask = timerTask;
this.delay = delay;
}
/**
* Create a new ScheduledTimerTask.
* @param timerTask the TimerTask to schedule
* @param delay the delay before starting the task for the first time (ms)
* @param period the period between repeated task executions (ms)
* @param fixedRate whether to schedule as fixed-rate execution
*/
public ScheduledTimerTask(TimerTask timerTask, long delay, long period, boolean fixedRate) {
this.timerTask = timerTask;
this.delay = delay;
this.period = period;
this.fixedRate = fixedRate;
}
/**
* Create a new ScheduledTimerTask, with default
* one-time execution without delay.
* @param timerTask the Runnable to schedule as TimerTask
*/
public ScheduledTimerTask(Runnable timerTask) {
setRunnable(timerTask);
}
/**
* Create a new ScheduledTimerTask, with default
* one-time execution with the given delay.
* @param timerTask the Runnable to schedule as TimerTask
* @param delay the delay before starting the task for the first time (ms)
*/
public ScheduledTimerTask(Runnable timerTask, long delay) {
setRunnable(timerTask);
this.delay = delay;
}
/**
* Create a new ScheduledTimerTask.
* @param timerTask the Runnable to schedule as TimerTask
* @param delay the delay before starting the task for the first time (ms)
* @param period the period between repeated task executions (ms)
* @param fixedRate whether to schedule as fixed-rate execution
*/
public ScheduledTimerTask(Runnable timerTask, long delay, long period, boolean fixedRate) {
setRunnable(timerTask);
this.delay = delay;
this.period = period;
this.fixedRate = fixedRate;
}
/**
* Set the Runnable to schedule as TimerTask.
* @see DelegatingTimerTask
*/
public void setRunnable(Runnable timerTask) {
this.timerTask = new DelegatingTimerTask(timerTask);
}
/**
* Set the TimerTask to schedule.
*/
public void setTimerTask(TimerTask timerTask) {
this.timerTask = timerTask;
}
/**
* Return the TimerTask to schedule.
*/
public TimerTask getTimerTask() {
return this.timerTask;
}
/**
* Set the delay before starting the task for the first time,
* in milliseconds. Default is 0, immediately starting the
* task after successful scheduling.
*/
public void setDelay(long delay) {
this.delay = delay;
}
/**
* Return the delay before starting the job for the first time.
*/
public long getDelay() {
return this.delay;
}
/**
* Set the period between repeated task executions, in milliseconds.
* <p>Default is -1, leading to one-time execution. In case of a positive
* value, the task will be executed repeatedly, with the given interval
* inbetween executions.
* <p>Note that the semantics of the period value vary between fixed-rate
* and fixed-delay execution.
* <p><b>Note:</b> A period of 0 (for example as fixed delay) is <i>not</i>
* supported, simply because <code>java.util.Timer</code> itself does not
* support it. Hence a value of 0 will be treated as one-time execution;
* however, that value should never be specified explicitly in the first place!
* @see #setFixedRate
* @see #isOneTimeTask()
* @see java.util.Timer#schedule(TimerTask, long, long)
*/
public void setPeriod(long period) {
this.period = period;
}
/**
* Return the period between repeated task executions.
*/
public long getPeriod() {
return this.period;
}
/**
* Is this task only ever going to execute once?
* @return <code>true</code> if this task is only ever going to execute once
* @see #getPeriod()
*/
public boolean isOneTimeTask() {
return (this.period <= 0);
}
/**
* Set whether to schedule as fixed-rate execution, rather than
* fixed-delay execution. Default is "false", that is, fixed delay.
* <p>See Timer javadoc for details on those execution modes.
* @see java.util.Timer#schedule(TimerTask, long, long)
* @see java.util.Timer#scheduleAtFixedRate(TimerTask, long, long)
*/
public void setFixedRate(boolean fixedRate) {
this.fixedRate = fixedRate;
}
/**
* Return whether to schedule as fixed-rate execution.
*/
public boolean isFixedRate() {
return this.fixedRate;
}
}