Class CronExpression
- java.lang.Object
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- org.apache.tapestry5.ioc.internal.services.cron.CronExpression
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- All Implemented Interfaces:
java.io.Serializable,java.lang.Cloneable
public final 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:
Supported Cron fields Field Name Allowed Values Allowed Special Characters Seconds0-59, - * /Minutes0-59, - * /Hours0-23, - * /Day-of-month1-31, - * ? / L WMonth0-11 or JAN-DEC, - * /Day-of-Week1-7 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 0 to 11 (JAN to DEC). 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:
- Support for specifying both a day-of-week and a day-of-month value is not complete (you'll need to use the '?' character in one of these fields).
- Overflowing ranges is supported - that is, having a larger number on the left hand side than the right. You might do 22-2 to catch 10 o'clock at night until 2 o'clock in the morning, or you might have NOV-FEB. It is very important to note that overuse of overflowing ranges creates ranges that don't make sense and no effort has been made to determine which interpretation CronExpression chooses. An example would be "0 0 14-6 ? * FRI-MON".
- See Also:
- Serialized Form
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Field Summary
Fields Modifier and Type Field Description protected static java.lang.IntegerALL_SPECprotected static intALL_SPEC_INTprotected static intDAY_OF_MONTHprotected static intDAY_OF_WEEKprotected static java.util.Map<java.lang.String,java.lang.Integer>dayMapprotected java.util.TreeSet<java.lang.Integer>daysOfMonthprotected java.util.TreeSet<java.lang.Integer>daysOfWeekprotected booleanexpressionParsedprotected static intHOURprotected java.util.TreeSet<java.lang.Integer>hoursprotected intlastdayOffsetprotected booleanlastdayOfMonthprotected booleanlastdayOfWeekstatic intMAX_YEARprotected static intMINUTEprotected java.util.TreeSet<java.lang.Integer>minutesprotected static intMONTHprotected static java.util.Map<java.lang.String,java.lang.Integer>monthMapprotected java.util.TreeSet<java.lang.Integer>monthsprotected booleannearestWeekdayprotected static java.lang.IntegerNO_SPECprotected static intNO_SPEC_INTprotected intnthdayOfWeekprotected static intSECONDprotected java.util.TreeSet<java.lang.Integer>secondsprotected static intYEARprotected java.util.TreeSet<java.lang.Integer>years
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Constructor Summary
Constructors Constructor Description CronExpression(java.lang.String cronExpression)Constructs a newCronExpressionbased on the specified parameter.CronExpression(CronExpression expression)Constructs a newCronExpressionas a copy of an existing instance.
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Method Summary
All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods Modifier and Type Method Description protected voidaddToSet(int val, int end, int incr, int type)protected voidbuildExpression(java.lang.String expression)protected intcheckNext(int pos, java.lang.String s, int val, int type)java.lang.Objectclone()Deprecated.protected intfindNextWhiteSpace(int i, java.lang.String s)java.lang.StringgetCronExpression()protected intgetDayOfWeekNumber(java.lang.String s)protected java.lang.StringgetExpressionSetSummary(java.util.ArrayList<java.lang.Integer> list)protected java.lang.StringgetExpressionSetSummary(java.util.Set<java.lang.Integer> set)java.lang.StringgetExpressionSummary()java.util.DategetFinalFireTime()NOT YET IMPLEMENTED: Returns the final time that theCronExpressionwill match.protected intgetLastDayOfMonth(int monthNum, int year)protected intgetMonthNumber(java.lang.String s)java.util.DategetNextInvalidTimeAfter(java.util.Date date)Returns the next date/time after the given date/time which does not satisfy the expressionjava.util.DategetNextValidTimeAfter(java.util.Date date)Returns the next date/time after the given date/time which satisfies the cron expression.protected intgetNumericValue(java.lang.String s, int i)java.util.DategetTimeAfter(java.util.Date afterTime)java.util.DategetTimeBefore(java.util.Date endTime)NOT YET IMPLEMENTED: Returns the time before the given time that theCronExpressionmatches.java.util.TimeZonegetTimeZone()Returns the time zone for which thisCronExpressionwill be resolved.protected org.apache.tapestry5.ioc.internal.services.cron.ValueSetgetValue(int v, java.lang.String s, int i)protected booleanisLeapYear(int year)booleanisSatisfiedBy(java.util.Date date)Indicates whether the given date satisfies the cron expression.static booleanisValidExpression(java.lang.String cronExpression)Indicates whether the specified cron expression can be parsed into a valid cron expressionprotected voidsetCalendarHour(java.util.Calendar cal, int hour)Advance the calendar to the particular hour paying particular attention to daylight saving problems.voidsetTimeZone(java.util.TimeZone timeZone)Sets the time zone for which thisCronExpressionwill be resolved.protected intskipWhiteSpace(int i, java.lang.String s)protected intstoreExpressionVals(int pos, java.lang.String s, int type)java.lang.StringtoString()Returns the string representation of theCronExpressionstatic voidvalidateExpression(java.lang.String cronExpression)
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Field Detail
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SECOND
protected static final int SECOND
- See Also:
- Constant Field Values
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MINUTE
protected static final int MINUTE
- See Also:
- Constant Field Values
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HOUR
protected static final int HOUR
- See Also:
- Constant Field Values
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DAY_OF_MONTH
protected static final int DAY_OF_MONTH
- See Also:
- Constant Field Values
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MONTH
protected static final int MONTH
- See Also:
- Constant Field Values
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DAY_OF_WEEK
protected static final int DAY_OF_WEEK
- See Also:
- Constant Field Values
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YEAR
protected static final int YEAR
- See Also:
- Constant Field Values
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ALL_SPEC_INT
protected static final int ALL_SPEC_INT
- See Also:
- Constant Field Values
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NO_SPEC_INT
protected static final int NO_SPEC_INT
- See Also:
- Constant Field Values
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ALL_SPEC
protected static final java.lang.Integer ALL_SPEC
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NO_SPEC
protected static final java.lang.Integer NO_SPEC
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monthMap
protected static final java.util.Map<java.lang.String,java.lang.Integer> monthMap
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dayMap
protected static final java.util.Map<java.lang.String,java.lang.Integer> dayMap
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seconds
protected transient java.util.TreeSet<java.lang.Integer> seconds
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minutes
protected transient java.util.TreeSet<java.lang.Integer> minutes
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hours
protected transient java.util.TreeSet<java.lang.Integer> hours
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daysOfMonth
protected transient java.util.TreeSet<java.lang.Integer> daysOfMonth
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months
protected transient java.util.TreeSet<java.lang.Integer> months
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daysOfWeek
protected transient java.util.TreeSet<java.lang.Integer> daysOfWeek
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years
protected transient java.util.TreeSet<java.lang.Integer> years
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lastdayOfWeek
protected transient boolean lastdayOfWeek
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nthdayOfWeek
protected transient int nthdayOfWeek
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lastdayOfMonth
protected transient boolean lastdayOfMonth
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nearestWeekday
protected transient boolean nearestWeekday
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lastdayOffset
protected transient int lastdayOffset
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expressionParsed
protected transient boolean expressionParsed
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MAX_YEAR
public static final int MAX_YEAR
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Constructor Detail
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CronExpression
public CronExpression(java.lang.String cronExpression) throws java.text.ParseException
Constructs a newCronExpressionbased 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 validCronExpression
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CronExpression
public CronExpression(CronExpression expression)
Constructs a newCronExpressionas a copy of an existing instance.- Parameters:
expression- The existing cron expression to be copied
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Method Detail
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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
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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
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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
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getTimeZone
public java.util.TimeZone getTimeZone()
Returns the time zone for which thisCronExpressionwill be resolved.
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setTimeZone
public void setTimeZone(java.util.TimeZone timeZone)
Sets the time zone for which thisCronExpressionwill be resolved.
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toString
public java.lang.String toString()
Returns the string representation of theCronExpression- Overrides:
toStringin classjava.lang.Object- Returns:
- a string representation of the
CronExpression
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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
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validateExpression
public static void validateExpression(java.lang.String cronExpression) throws java.text.ParseException
- Throws:
java.text.ParseException
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buildExpression
protected void buildExpression(java.lang.String expression) throws java.text.ParseException
- Throws:
java.text.ParseException
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storeExpressionVals
protected int storeExpressionVals(int pos, java.lang.String s, int type) throws java.text.ParseException
- Throws:
java.text.ParseException
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checkNext
protected int checkNext(int pos, java.lang.String s, int val, int type) throws java.text.ParseException
- Throws:
java.text.ParseException
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getCronExpression
public java.lang.String getCronExpression()
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getExpressionSummary
public java.lang.String getExpressionSummary()
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getExpressionSetSummary
protected java.lang.String getExpressionSetSummary(java.util.Set<java.lang.Integer> set)
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getExpressionSetSummary
protected java.lang.String getExpressionSetSummary(java.util.ArrayList<java.lang.Integer> list)
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skipWhiteSpace
protected int skipWhiteSpace(int i, java.lang.String s)
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findNextWhiteSpace
protected int findNextWhiteSpace(int i, java.lang.String s)
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addToSet
protected void addToSet(int val, int end, int incr, int type) throws java.text.ParseException
- Throws:
java.text.ParseException
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getValue
protected org.apache.tapestry5.ioc.internal.services.cron.ValueSet getValue(int v, java.lang.String s, int i)
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getNumericValue
protected int getNumericValue(java.lang.String s, int i)
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getMonthNumber
protected int getMonthNumber(java.lang.String s)
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getDayOfWeekNumber
protected int getDayOfWeekNumber(java.lang.String s)
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getTimeAfter
public java.util.Date getTimeAfter(java.util.Date afterTime)
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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- the calendar to operate onhour- the hour to set
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getTimeBefore
public java.util.Date getTimeBefore(java.util.Date endTime)
NOT YET IMPLEMENTED: Returns the time before the given time that theCronExpressionmatches.
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getFinalFireTime
public java.util.Date getFinalFireTime()
NOT YET IMPLEMENTED: Returns the final time that theCronExpressionwill match.
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isLeapYear
protected boolean isLeapYear(int year)
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getLastDayOfMonth
protected int getLastDayOfMonth(int monthNum, int year)
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clone
@Deprecated public java.lang.Object clone()
Deprecated.- Overrides:
clonein classjava.lang.Object
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