Jive Forums API (5.5.20.2-oracle) Developer Javadocs

com.jivesoftware.util
Class CronTimer

java.lang.Object
  extended by com.jivesoftware.util.CronTimer
All Implemented Interfaces:
java.io.Serializable

public class CronTimer
extends java.lang.Object
implements java.io.Serializable

A class that is used to fire at given moment in time, defined with Unix 'cron-like' definitions.

For those unfamiliar with "cron", this means being able to create a firing schedule such as: "At 8:00am every Monday through Friday" or "At 1:30am every last Friday of the month".

A "Cron-Expression" is a string comprised of 6 or 7 fields separated by white space. The 6 mandatory and 1 optional fields are as follows:

Field Name   Allowed Values   Allowed Special Characters
Seconds   0-59   , - * /
Minutes   0-59   , - * /
Hours   0-23   , - * /
Day-of-month   1-31   , - * ? / L C
Month   1-12 or JAN-DEC   , - * /
Day-of-Week   1-7 or SUN-SAT   , - * ? / L C #
Year (Optional)   empty, 1970-2099   , - * /

The '*' character is used to specify all values. For example, "*" in the minute field means "every minute".

The '?' character is allowed for the day-of-month and day-of-week fields. It is used to specify 'no specific value'. This is useful when you need to specify something in one of the two fields, but not the other. See the examples below for clarification.

The '-' character is used to specify ranges For example "10-12" in the hour field means "the hours 10, 11 and 12".

The ',' character is used to specify additional values. For example "MON,WED,FRI" in the day-of-week field means "the days Monday, Wednesday, and Friday".

The '/' character is used to specify increments. For example "0/15" in the seconds field means "the seconds 0, 15, 30, and 45". And "5/15" in the seconds field means "the seconds 5, 20, 35, and 50". You can also specify '/' after the '*' character - in this case '*' is equivalent to having '0' before the '/'.

The 'L' character is allowed for the day-of-month and day-of-week fields. This character is short-hand for "last", but it has different meaning in each of the two fields. For example, the value "L" in the day-of-month field means "the last day of the month" - day 31 for January, day 28 for February on non-leap years. If used in the day-of-week field by itself, it simply means "7" or "SAT". But if used in the day-of-week field after another value, it means "the last xxx day of the month" - for example "6L" means "the last friday of the month". When using the 'L' option, it is important not to specify lists, or ranges of values, as you'll get confusing results.

The '#' character is allowed for the day-of-week field. This character is used to specify "the nth" XXX day of the month. For example, the value of "6#3" in the day-of-week field means the third Friday of the month (day 6 = Friday and "#3" = the 3rd one in the month). Other examples: "2#1" = the first Monday of the month and "4#5" = the fifth Wednesday of the month. Note that if you specify "#5" and there is not 5 of the given day-of-week in the month, then no firing will occur that month.

The 'C' character is allowed for the day-of-month and day-of-week fields. This character is short-hand for "calendar". This means values are calculated against the associated calendar, if any. If no calendar is associated, then it is equivalent to having an all-inclusive calendar. A value of "5C" in the day-of-month field means "the first day included by the calendar on or after the 5th". A value of "1C" in the day-of-week field means "the first day included by the calendar on or after sunday".

The legal characters and the names of months and days of the week are not case sensitive.

Here are some full examples:

Expression   Meaning
"0 0 12 * * ?"   Fire at 12pm (noon) every day
"0 15 10 ? * *"   Fire at 10:15am every day
"0 15 10 * * ?"   Fire at 10:15am every day
"0 15 10 * * ? *"   Fire at 10:15am every day
"0 15 10 * * ? 2005"   Fire at 10:15am every day during the year 2005
"0 * 14 * * ?"   Fire every minute starting at 2pm and ending at 2:59pm, every day
"0 0/5 14 * * ?"   Fire every 5 minutes starting at 2pm and ending at 2:55pm, every day
"0 0/5 14,18 * * ?"   Fire every 5 minutes starting at 2pm and ending at 2:55pm, AND fire every 5 minutes starting at 6pm and ending at 6:55pm, every day
"0 0-5 14 * * ?"   Fire every minute starting at 2pm and ending at 2:05pm, every day
"0 10,44 14 ? 3 WED"   Fire at 2:10pm and at 2:44pm every Wednesday in the month of March.
"0 15 10 ? * MON-FRI"   Fire at 10:15am every Monday, Tuesday, Wednesday, Thursday and Friday
"0 15 10 15 * ?"   Fire at 10:15am on the 15th day of every month
"0 15 10 L * ?"   Fire at 10:15am on the last day of every month
"0 15 10 ? * 6L"   Fire at 10:15am on the last Friday of every month
"0 15 10 ? * 6L"   Fire at 10:15am on the last Friday of every month
"0 15 10 ? * 6L 2002-2005"   Fire at 10:15am on every last friday of every month during the years 2002, 2003, 2004 and 2005
"0 15 10 ? * 6#3"   Fire at 10:15am on the third Friday of every month

Pay attention to the effects of '?' and '*' in the day-of-week and day-of-month fields!

NOTES:

See Also:
Serialized Form

Constructor Summary
CronTimer(java.lang.String cronExpression)
           
 
Method Summary
 boolean equals(java.lang.Object o)
           
 java.lang.String getCronExpression()
           
 java.lang.String getExpressionSummary()
           
 int getLastDayOfMonth(int monthNum, int year)
           
 java.util.Date getNextFireTime()
           
 java.util.Date getNextFireTimeAfter(java.util.Date afterTime)
          Returns the next time at which the CronTimer will fire, after the given time.
 java.util.Date getStartTime()
          Get the time at which the timer should start
 java.util.TimeZone getTimeZone()
          Returns the time zone for which the cronExpression of this CronTimer will be resolved.
 int hashCode()
           
 boolean isLeapYear(int year)
           
 void setCronExpression(java.lang.String cronExpression)
           
 void setTimeZone(java.util.TimeZone timeZone)
          Sets the time zone for which the cronExpression of this CronTimer will be resolved.
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

CronTimer

public CronTimer(java.lang.String cronExpression)
          throws java.text.ParseException
Throws:
java.text.ParseException
Method Detail

setCronExpression

public void setCronExpression(java.lang.String cronExpression)
                       throws java.text.ParseException
Throws:
java.text.ParseException

getCronExpression

public java.lang.String getCronExpression()

getStartTime

public java.util.Date getStartTime()
Get the time at which the timer should start


getTimeZone

public java.util.TimeZone getTimeZone()
Returns the time zone for which the cronExpression of this CronTimer will be resolved.


setTimeZone

public void setTimeZone(java.util.TimeZone timeZone)
Sets the time zone for which the cronExpression of this CronTimer will be resolved.


getNextFireTime

public java.util.Date getNextFireTime()

getNextFireTimeAfter

public java.util.Date getNextFireTimeAfter(java.util.Date afterTime)
Returns the next time at which the CronTimer will fire, after the given time. If the timer will not fire after the given time, null will be returned.


getExpressionSummary

public java.lang.String getExpressionSummary()

isLeapYear

public boolean isLeapYear(int year)

getLastDayOfMonth

public int getLastDayOfMonth(int monthNum,
                             int year)

equals

public boolean equals(java.lang.Object o)
Overrides:
equals in class java.lang.Object

hashCode

public int hashCode()
Overrides:
hashCode in class java.lang.Object

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