CronCalendar.java
package org.quartz.impl.calendar;
import java.text.ParseException;
import java.util.Date;
import java.util.TimeZone;
import org.quartz.Calendar;
import org.quartz.CronExpression;
/**
* This implementation of the Calendar excludes the set of times expressed by a
* given {@link org.quartz.CronExpression CronExpression}. For example, you
* could use this calendar to exclude all but business hours (8AM - 5PM) every
* day using the expression "* * 0-7,18-23 ? * *".
* <P>
* It is important to remember that the cron expression here describes a set of
* times to be <I>excluded</I> from firing. Whereas the cron expression in
* {@link org.quartz.CronTrigger CronTrigger} describes a set of times that can
* be <I>included</I> for firing. Thus, if a <CODE>CronTrigger</CODE> has a
* given cron expression and is associated with a <CODE>CronCalendar</CODE> with
* the <I>same</I> expression, the calendar will exclude all the times the
* trigger includes, and they will cancel each other out.
*
* @author Aaron Craven
*/
public class CronCalendar extends BaseCalendar {
private static final long serialVersionUID = -8172103999750856831L;
CronExpression cronExpression;
/**
* Create a <CODE>CronCalendar</CODE> with the given cron expression and no
* <CODE>baseCalendar</CODE>.
*
* @param expression a String representation of the desired cron expression
*/
public CronCalendar(String expression)
throws ParseException {
this(null, expression, null);
}
/**
* Create a <CODE>CronCalendar</CODE> with the given cron expression and
* <CODE>baseCalendar</CODE>.
*
* @param baseCalendar the base calendar for this calendar instance –
* see {@link BaseCalendar} for more information on base
* calendar functionality
* @param expression a String representation of the desired cron expression
*/
public CronCalendar(Calendar baseCalendar,
String expression) throws ParseException {
this(baseCalendar, expression, null);
}
/**
* Create a <CODE>CronCalendar</CODE> with the given cron expression,
* <CODE>baseCalendar</CODE>, and <code>TimeZone</code>.
*
* @param baseCalendar the base calendar for this calendar instance –
* see {@link BaseCalendar} for more information on base
* calendar functionality
* @param expression a String representation of the desired cron expression
* @param timeZone
* Specifies for which time zone the <code>expression</code>
* should be interpreted, i.e. the expression 0 0 10 * * ?, is
* resolved to 10:00 am in this time zone. If
* <code>timeZone</code> is <code>null</code> then
* <code>TimeZone.getDefault()</code> will be used.
*/
public CronCalendar(Calendar baseCalendar,
String expression, TimeZone timeZone) throws ParseException {
super(baseCalendar);
this.cronExpression = new CronExpression(expression);
this.cronExpression.setTimeZone(timeZone);
}
@Override
public Object clone() {
CronCalendar clone = (CronCalendar) super.clone();
clone.cronExpression = new CronExpression(cronExpression);
return clone;
}
/**
* Returns the time zone for which the <code>CronExpression</code> of
* this <code>CronCalendar</code> will be resolved.
* <p>
* Overrides <code>{@link BaseCalendar#getTimeZone()}</code> to
* defer to its <code>CronExpression</code>.
* </p>
*/
@Override
public TimeZone getTimeZone() {
return cronExpression.getTimeZone();
}
/**
* Sets the time zone for which the <code>CronExpression</code> of this
* <code>CronCalendar</code> will be resolved. If <code>timeZone</code>
* is <code>null</code> then <code>TimeZone.getDefault()</code> will be
* used.
* <p>
* Overrides <code>{@link BaseCalendar#setTimeZone(TimeZone)}</code> to
* defer to its <code>CronExpression</code>.
* </p>
*/
@Override
public void setTimeZone(TimeZone timeZone) {
cronExpression.setTimeZone(timeZone);
}
/**
* Determines whether the given time (in milliseconds) is 'included' by the
* <CODE>BaseCalendar</CODE>
*
* @param timeInMillis the date/time to test
* @return a boolean indicating whether the specified time is 'included' by
* the <CODE>CronCalendar</CODE>
*/
@Override
public boolean isTimeIncluded(long timeInMillis) {
if ((getBaseCalendar() != null) &&
(!getBaseCalendar().isTimeIncluded(timeInMillis))) {
return false;
}
return (!(cronExpression.isSatisfiedBy(new Date(timeInMillis))));
}
/**
* Determines the next time included by the <CODE>CronCalendar</CODE>
* after the specified time.
*
* @param timeInMillis the initial date/time after which to find an
* included time
* @return the time in milliseconds representing the next time included
* after the specified time.
*/
@Override
public long getNextIncludedTime(long timeInMillis) {
long nextIncludedTime = timeInMillis + 1; //plus on millisecond
while (!isTimeIncluded(nextIncludedTime)) {
//If the time is in a range excluded by this calendar, we can
// move to the end of the excluded time range and continue testing
// from there. Otherwise, if nextIncludedTime is excluded by the
// baseCalendar, ask it the next time it includes and begin testing
// from there. Failing this, add one millisecond and continue
// testing.
if (cronExpression.isSatisfiedBy(new Date(nextIncludedTime))) {
nextIncludedTime = cronExpression.getNextInvalidTimeAfter(
new Date(nextIncludedTime)).getTime();
} else if ((getBaseCalendar() != null) &&
(!getBaseCalendar().isTimeIncluded(nextIncludedTime))){
nextIncludedTime =
getBaseCalendar().getNextIncludedTime(nextIncludedTime);
} else {
nextIncludedTime++;
}
}
return nextIncludedTime;
}
/**
* Returns a string representing the properties of the
* <CODE>CronCalendar</CODE>
*
* @return the properties of the CronCalendar in a String format
*/
@Override
public String toString() {
StringBuffer buffer = new StringBuffer();
buffer.append("base calendar: [");
if (getBaseCalendar() != null) {
buffer.append(getBaseCalendar().toString());
} else {
buffer.append("null");
}
buffer.append("], excluded cron expression: '");
buffer.append(cronExpression);
buffer.append("'");
return buffer.toString();
}
/**
* Returns the object representation of the cron expression that defines the
* dates and times this calendar excludes.
*
* @return the cron expression
* @see org.quartz.CronExpression
*/
public CronExpression getCronExpression() {
return cronExpression;
}
/**
* Sets the cron expression for the calendar to a new value
*
* @param expression the new string value to build a cron expression from
* @throws ParseException
* if the string expression cannot be parsed
*/
public void setCronExpression(String expression) throws ParseException {
this.cronExpression = new CronExpression(expression);
}
/**
* Sets the cron expression for the calendar to a new value
*
* @param expression the new cron expression
*/
public void setCronExpression(CronExpression expression) {
if (expression == null) {
throw new IllegalArgumentException("expression cannot be null");
}
this.cronExpression = expression;
}
}