org.quartz
Class CronExpression

java.lang.Object
  extended by org.quartz.CronExpression
All Implemented Interfaces:
java.io.Serializable, java.lang.Cloneable

public class CronExpression
extends java.lang.Object
implements java.io.Serializable, java.lang.Cloneable

Provides a parser and evaluator for unix-like cron expressions. Cron expressions provide the ability to specify complex time combinations such as "At 8:00am every Monday through Friday" or "At 1:30am every last Friday of the month".

Cron expressions are comprised of 6 required fields and one optional field separated by white space. The fields respectively are described as follows:

Field Name   Allowed Values   Allowed Special Characters
Seconds   0-59   , - * /
Minutes   0-59   , - * /
Hours   0-23   , - * /
Day-of-month   1-31   , - * ? / L W
Month   1-12 or JAN-DEC   , - * /
Day-of-Week   1-7 or SUN-SAT   , - * ? / L #
Year (Optional)   empty, 1970-2199   , - * /

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.

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". Specifying '*' before the '/' is equivalent to specifying 0 is the value to start with. Essentially, for each field in the expression, there is a set of numbers that can be turned on or off. For seconds and minutes, the numbers range from 0 to 59. For hours 0 to 23, for days of the month 0 to 31, and for months 1 to 12. The "/" character simply helps you turn on every "nth" value in the given set. Thus "7/6" in the month field only turns on month "7", it does NOT mean every 6th month, please note that subtlety.

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". You can also specify an offset from the last day of the month, such as "L-3" which would mean the third-to-last day of the calendar month. When using the 'L' option, it is important not to specify lists, or ranges of values, as you'll get confusing/unexpected results.

The 'W' character is allowed for the day-of-month field. This character is used to specify the weekday (Monday-Friday) nearest the given day. As an example, if you were to specify "15W" as the value for the day-of-month field, the meaning is: "the nearest weekday to the 15th of the month". So if the 15th is a Saturday, the trigger will fire on Friday the 14th. If the 15th is a Sunday, the trigger will fire on Monday the 16th. If the 15th is a Tuesday, then it will fire on Tuesday the 15th. However if you specify "1W" as the value for day-of-month, and the 1st is a Saturday, the trigger will fire on Monday the 3rd, as it will not 'jump' over the boundary of a month's days. The 'W' character can only be specified when the day-of-month is a single day, not a range or list of days.

The 'L' and 'W' characters can also be combined for the day-of-month expression to yield 'LW', which translates to "last weekday of the month".

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. If the '#' character is used, there can only be one expression in the day-of-week field ("3#1,6#3" is not valid, since there are two expressions).

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

NOTES:

Author:
Sharada Jambula, James House, Contributions from Mads Henderson, Refactoring from CronTrigger to CronExpression by Aaron Craven
See Also:
Serialized Form

Field Summary
protected static java.lang.Integer ALL_SPEC
           
protected static int ALL_SPEC_INT
           
protected static int DAY_OF_MONTH
           
protected static int DAY_OF_WEEK
           
protected static java.util.Map<java.lang.String,java.lang.Integer> dayMap
           
protected  java.util.TreeSet<java.lang.Integer> daysOfMonth
           
protected  java.util.TreeSet<java.lang.Integer> daysOfWeek
           
protected  boolean expressionParsed
           
protected static int HOUR
           
protected  java.util.TreeSet<java.lang.Integer> hours
           
protected  int lastdayOffset
           
protected  boolean lastdayOfMonth
           
protected  boolean lastdayOfWeek
           
static int MAX_YEAR
           
protected static int MINUTE
           
protected  java.util.TreeSet<java.lang.Integer> minutes
           
protected static int MONTH
           
protected static java.util.Map<java.lang.String,java.lang.Integer> monthMap
           
protected  java.util.TreeSet<java.lang.Integer> months
           
protected  boolean nearestWeekday
           
protected static java.lang.Integer NO_SPEC
           
protected static int NO_SPEC_INT
           
protected  int nthdayOfWeek
           
protected static int SECOND
           
protected  java.util.TreeSet<java.lang.Integer> seconds
           
protected static int YEAR
           
protected  java.util.TreeSet<java.lang.Integer> years
           
 
Constructor Summary
CronExpression(java.lang.String cronExpression)
          Constructs a new CronExpression based on the specified parameter.
 
Method Summary
protected  void addToSet(int val, int end, int incr, int type)
           
protected  void buildExpression(java.lang.String expression)
           
protected  int checkNext(int pos, java.lang.String s, int val, int type)
           
 java.lang.Object clone()
           
protected  int findNextWhiteSpace(int i, java.lang.String s)
           
 java.lang.String getCronExpression()
           
protected  int getDayOfWeekNumber(java.lang.String s)
           
protected  java.lang.String getExpressionSetSummary(java.util.ArrayList<java.lang.Integer> list)
           
protected  java.lang.String getExpressionSetSummary(java.util.Set<java.lang.Integer> set)
           
 java.lang.String getExpressionSummary()
           
 java.util.Date getFinalFireTime()
          NOT YET IMPLEMENTED: Returns the final time that the CronExpression will match.
protected  int getLastDayOfMonth(int monthNum, int year)
           
protected  int getMonthNumber(java.lang.String s)
           
 java.util.Date getNextInvalidTimeAfter(java.util.Date date)
          Returns the next date/time after the given date/time which does not satisfy the expression
 java.util.Date getNextValidTimeAfter(java.util.Date date)
          Returns the next date/time after the given date/time which satisfies the cron expression.
protected  int getNumericValue(java.lang.String s, int i)
           
protected  java.util.TreeSet<java.lang.Integer> getSet(int type)
           
 java.util.Date getTimeAfter(java.util.Date afterTime)
           
 java.util.Date getTimeBefore(java.util.Date endTime)
          NOT YET IMPLEMENTED: Returns the time before the given time that the CronExpression matches.
 java.util.TimeZone getTimeZone()
          Returns the time zone for which this CronExpression will be resolved.
protected  org.quartz.ValueSet getValue(int v, java.lang.String s, int i)
           
protected  boolean isLeapYear(int year)
           
 boolean isSatisfiedBy(java.util.Date date)
          Indicates whether the given date satisfies the cron expression.
static boolean isValidExpression(java.lang.String cronExpression)
          Indicates whether the specified cron expression can be parsed into a valid cron expression
protected  void setCalendarHour(java.util.Calendar cal, int hour)
          Advance the calendar to the particular hour paying particular attention to daylight saving problems.
 void setTimeZone(java.util.TimeZone timeZone)
          Sets the time zone for which this CronExpression will be resolved.
protected  int skipWhiteSpace(int i, java.lang.String s)
           
protected  int storeExpressionVals(int pos, java.lang.String s, int type)
           
 java.lang.String toString()
          Returns the string representation of the CronExpression
static void validateExpression(java.lang.String cronExpression)
           
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

SECOND

protected static final int SECOND
See Also:
Constant Field Values

MINUTE

protected static final int MINUTE
See Also:
Constant Field Values

HOUR

protected static final int HOUR
See Also:
Constant Field Values

DAY_OF_MONTH

protected static final int DAY_OF_MONTH
See Also:
Constant Field Values

MONTH

protected static final int MONTH
See Also:
Constant Field Values

DAY_OF_WEEK

protected static final int DAY_OF_WEEK
See Also:
Constant Field Values

YEAR

protected static final int YEAR
See Also:
Constant Field Values

ALL_SPEC_INT

protected static final int ALL_SPEC_INT
See Also:
Constant Field Values

NO_SPEC_INT

protected static final int NO_SPEC_INT
See Also:
Constant Field Values

ALL_SPEC

protected static final java.lang.Integer ALL_SPEC

NO_SPEC

protected static final java.lang.Integer NO_SPEC

monthMap

protected static final java.util.Map<java.lang.String,java.lang.Integer> monthMap

dayMap

protected static final java.util.Map<java.lang.String,java.lang.Integer> dayMap

seconds

protected transient java.util.TreeSet<java.lang.Integer> seconds

minutes

protected transient java.util.TreeSet<java.lang.Integer> minutes

hours

protected transient java.util.TreeSet<java.lang.Integer> hours

daysOfMonth

protected transient java.util.TreeSet<java.lang.Integer> daysOfMonth

months

protected transient java.util.TreeSet<java.lang.Integer> months

daysOfWeek

protected transient java.util.TreeSet<java.lang.Integer> daysOfWeek

years

protected transient java.util.TreeSet<java.lang.Integer> years

lastdayOfWeek

protected transient boolean lastdayOfWeek

nthdayOfWeek

protected transient int nthdayOfWeek

lastdayOfMonth

protected transient boolean lastdayOfMonth

nearestWeekday

protected transient boolean nearestWeekday

lastdayOffset

protected transient int lastdayOffset

expressionParsed

protected transient boolean expressionParsed

MAX_YEAR

public static final int MAX_YEAR
Constructor Detail

CronExpression

public CronExpression(java.lang.String cronExpression)
               throws java.text.ParseException
Constructs a new CronExpression based on the specified parameter.

Parameters:
cronExpression - String representation of the cron expression the new object should represent
Throws:
java.text.ParseException - if the string expression cannot be parsed into a valid CronExpression
Method Detail

isSatisfiedBy

public boolean isSatisfiedBy(java.util.Date date)
Indicates whether the given date satisfies the cron expression. Note that milliseconds are ignored, so two Dates falling on different milliseconds of the same second will always have the same result here.

Parameters:
date - the date to evaluate
Returns:
a boolean indicating whether the given date satisfies the cron expression

getNextValidTimeAfter

public java.util.Date getNextValidTimeAfter(java.util.Date date)
Returns the next date/time after the given date/time which satisfies the cron expression.

Parameters:
date - the date/time at which to begin the search for the next valid date/time
Returns:
the next valid date/time

getNextInvalidTimeAfter

public java.util.Date getNextInvalidTimeAfter(java.util.Date date)
Returns the next date/time after the given date/time which does not satisfy the expression

Parameters:
date - the date/time at which to begin the search for the next invalid date/time
Returns:
the next valid date/time

getTimeZone

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


setTimeZone

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


toString

public java.lang.String toString()
Returns the string representation of the CronExpression

Overrides:
toString in class java.lang.Object
Returns:
a string representation of the CronExpression

isValidExpression

public static boolean isValidExpression(java.lang.String cronExpression)
Indicates whether the specified cron expression can be parsed into a valid cron expression

Parameters:
cronExpression - the expression to evaluate
Returns:
a boolean indicating whether the given expression is a valid cron expression

validateExpression

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

buildExpression

protected void buildExpression(java.lang.String expression)
                        throws java.text.ParseException
Throws:
java.text.ParseException

storeExpressionVals

protected int storeExpressionVals(int pos,
                                  java.lang.String s,
                                  int type)
                           throws java.text.ParseException
Throws:
java.text.ParseException

checkNext

protected int checkNext(int pos,
                        java.lang.String s,
                        int val,
                        int type)
                 throws java.text.ParseException
Throws:
java.text.ParseException

getCronExpression

public java.lang.String getCronExpression()

getExpressionSummary

public java.lang.String getExpressionSummary()

getExpressionSetSummary

protected java.lang.String getExpressionSetSummary(java.util.Set<java.lang.Integer> set)

getExpressionSetSummary

protected java.lang.String getExpressionSetSummary(java.util.ArrayList<java.lang.Integer> list)

skipWhiteSpace

protected int skipWhiteSpace(int i,
                             java.lang.String s)

findNextWhiteSpace

protected int findNextWhiteSpace(int i,
                                 java.lang.String s)

addToSet

protected void addToSet(int val,
                        int end,
                        int incr,
                        int type)
                 throws java.text.ParseException
Throws:
java.text.ParseException

getSet

protected java.util.TreeSet<java.lang.Integer> getSet(int type)

getValue

protected org.quartz.ValueSet getValue(int v,
                                       java.lang.String s,
                                       int i)

getNumericValue

protected int getNumericValue(java.lang.String s,
                              int i)

getMonthNumber

protected int getMonthNumber(java.lang.String s)

getDayOfWeekNumber

protected int getDayOfWeekNumber(java.lang.String s)

getTimeAfter

public java.util.Date getTimeAfter(java.util.Date afterTime)

setCalendarHour

protected void setCalendarHour(java.util.Calendar cal,
                               int hour)
Advance the calendar to the particular hour paying particular attention to daylight saving problems.

Parameters:
cal -
hour -

getTimeBefore

public java.util.Date getTimeBefore(java.util.Date endTime)
NOT YET IMPLEMENTED: Returns the time before the given time that the CronExpression matches.


getFinalFireTime

public java.util.Date getFinalFireTime()
NOT YET IMPLEMENTED: Returns the final time that the CronExpression will match.


isLeapYear

protected boolean isLeapYear(int year)

getLastDayOfMonth

protected int getLastDayOfMonth(int monthNum,
                                int year)

clone

public java.lang.Object clone()
Overrides:
clone in class java.lang.Object


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