com.xxl.job.admin.core.cron

类 CronExpression

java.lang.Object

com.xxl.job.admin.core.cron.CronExpression

所有已实现的接口:

Serializable, Cloneable

public final class CronExpression
extends Object
implements Serializable, 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		0-11 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 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".

作者:

Sharada Jambula, James House, Contributions from Mads Henderson, Refactoring from CronTrigger to CronExpression by Aaron Craven

Borrowed from quartz v2.3.1

另请参阅:

序列化表格

字段概要

字段

限定符和类型	字段和说明
protected static Integer	ALL_SPEC
protected static int	ALL_SPEC_INT
private String	cronExpression
protected static int	DAY_OF_MONTH
protected static int	DAY_OF_WEEK
protected static Map<String,Integer>	dayMap
protected TreeSet<Integer>	daysOfMonth
protected TreeSet<Integer>	daysOfWeek
protected boolean	expressionParsed
protected static int	HOUR
protected TreeSet<Integer>	hours
protected int	lastdayOffset
protected boolean	lastdayOfMonth
protected boolean	lastdayOfWeek
static int	MAX_YEAR
protected static int	MINUTE
protected TreeSet<Integer>	minutes
protected static int	MONTH
protected static Map<String,Integer>	monthMap
protected TreeSet<Integer>	months
protected boolean	nearestWeekday
protected static Integer	NO_SPEC
protected static int	NO_SPEC_INT
protected int	nthdayOfWeek
protected static int	SECOND
protected TreeSet<Integer>	seconds
private static long	serialVersionUID
private TimeZone	timeZone
protected static int	YEAR
protected TreeSet<Integer>	years

构造器概要

构造器

构造器和说明
CronExpression(CronExpression expression) Constructs a new CronExpression as a copy of an existing instance.
CronExpression(String cronExpression) Constructs a new CronExpression based on the specified parameter.

方法概要

限定符和类型	方法和说明
protected void	addToSet(int val, int end, int incr, int type)
protected void	buildExpression(String expression)
private void	checkIncrementRange(int incr, int type, int idxPos)
protected int	checkNext(int pos, String s, int val, int type)
Object	clone() 已过时。
protected int	findNextWhiteSpace(int i, String s)
String	getCronExpression()
protected int	getDayOfWeekNumber(String s)
protected String	getExpressionSetSummary(ArrayList<Integer> list)
protected String	getExpressionSetSummary(Set<Integer> set)
String	getExpressionSummary()
Date	getFinalFireTime() NOT YET IMPLEMENTED: Returns the final time that the CronExpression will match.
protected int	getLastDayOfMonth(int monthNum, int year)
protected int	getMonthNumber(String s)
Date	getNextInvalidTimeAfter(Date date) Returns the next date/time after the given date/time which does not satisfy the expression
Date	getNextValidTimeAfter(Date date) Returns the next date/time after the given date/time which satisfies the cron expression.
protected int	getNumericValue(String s, int i)
(专用程序包) TreeSet<Integer>	getSet(int type)
Date	getTimeAfter(Date afterTime)
Date	getTimeBefore(Date endTime) NOT YET IMPLEMENTED: Returns the time before the given time that the CronExpression matches.
TimeZone	getTimeZone() Returns the time zone for which this CronExpression will be resolved.
protected ValueSet	getValue(int v, String s, int i)
protected boolean	isLeapYear(int year)
boolean	isSatisfiedBy(Date date) Indicates whether the given date satisfies the cron expression.
static boolean	isValidExpression(String cronExpression) Indicates whether the specified cron expression can be parsed into a valid cron expression
private void	readObject(ObjectInputStream stream)
protected void	setCalendarHour(Calendar cal, int hour) Advance the calendar to the particular hour paying particular attention to daylight saving problems.
void	setTimeZone(TimeZone timeZone) Sets the time zone for which this CronExpression will be resolved.
protected int	skipWhiteSpace(int i, String s)
protected int	storeExpressionVals(int pos, String s, int type)
String	toString() Returns the string representation of the CronExpression
static void	validateExpression(String cronExpression)

从类继承的方法 java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

字段详细资料

serialVersionUID

private static final long serialVersionUID

另请参阅:

常量字段值

SECOND

protected static final int SECOND

另请参阅:

常量字段值

MINUTE

protected static final int MINUTE

另请参阅:

常量字段值

HOUR

protected static final int HOUR

另请参阅:

常量字段值

DAY_OF_MONTH

protected static final int DAY_OF_MONTH

另请参阅:

常量字段值

MONTH

protected static final int MONTH

另请参阅:

常量字段值

DAY_OF_WEEK

protected static final int DAY_OF_WEEK

另请参阅:

常量字段值

YEAR

protected static final int YEAR

另请参阅:

常量字段值

ALL_SPEC_INT

protected static final int ALL_SPEC_INT

另请参阅:

常量字段值

NO_SPEC_INT

protected static final int NO_SPEC_INT

另请参阅:

常量字段值

ALL_SPEC

protected static final Integer ALL_SPEC

NO_SPEC

protected static final Integer NO_SPEC

monthMap

protected static final Map<String,Integer> monthMap

dayMap

protected static final Map<String,Integer> dayMap

cronExpression

private final String cronExpression

timeZone

private TimeZone timeZone

seconds

protected transient TreeSet<Integer> seconds

minutes

protected transient TreeSet<Integer> minutes

hours

protected transient TreeSet<Integer> hours

daysOfMonth

protected transient TreeSet<Integer> daysOfMonth

months

protected transient TreeSet<Integer> months

daysOfWeek

protected transient TreeSet<Integer> daysOfWeek

years

protected transient TreeSet<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

构造器详细资料

CronExpression

public CronExpression(String cronExpression)
               throws ParseException

Constructs a new CronExpression based on the specified parameter.

参数:

cronExpression - String representation of the cron expression the new object should represent

抛出:

ParseException - if the string expression cannot be parsed into a valid CronExpression

CronExpression

public CronExpression(CronExpression expression)

Constructs a new CronExpression as a copy of an existing instance.

参数:

expression - The existing cron expression to be copied

方法详细资料

isSatisfiedBy

public boolean isSatisfiedBy(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.

参数:

date - the date to evaluate

返回:

a boolean indicating whether the given date satisfies the cron expression

getNextValidTimeAfter

public Date getNextValidTimeAfter(Date date)

Returns the next date/time after the given date/time which satisfies the cron expression.

参数:

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

返回:

the next valid date/time

getNextInvalidTimeAfter

public Date getNextInvalidTimeAfter(Date date)

Returns the next date/time after the given date/time which does not satisfy the expression

参数:

date - the date/time at which to begin the search for the next invalid date/time

返回:

the next valid date/time

getTimeZone

public TimeZone getTimeZone()

Returns the time zone for which this CronExpression will be resolved.

setTimeZone

public void setTimeZone(TimeZone timeZone)

Sets the time zone for which this CronExpression will be resolved.

toString

public String toString()

Returns the string representation of the CronExpression

覆盖:

toString 在类中 Object

返回:

a string representation of the CronExpression

isValidExpression

public static boolean isValidExpression(String cronExpression)

Indicates whether the specified cron expression can be parsed into a valid cron expression

参数:

cronExpression - the expression to evaluate

返回:

a boolean indicating whether the given expression is a valid cron expression

validateExpression

public static void validateExpression(String cronExpression)
                               throws ParseException

抛出:

ParseException

buildExpression

protected void buildExpression(String expression)
                        throws ParseException

抛出:

ParseException

storeExpressionVals

protected int storeExpressionVals(int pos,
                                  String s,
                                  int type)
                           throws ParseException

抛出:

ParseException

checkIncrementRange

private void checkIncrementRange(int incr,
                                 int type,
                                 int idxPos)
                          throws ParseException

抛出:

ParseException

checkNext

protected int checkNext(int pos,
                        String s,
                        int val,
                        int type)
                 throws ParseException

抛出:

ParseException

getCronExpression

public String getCronExpression()

getExpressionSummary

public String getExpressionSummary()

getExpressionSetSummary

protected String getExpressionSetSummary(Set<Integer> set)

getExpressionSetSummary

protected String getExpressionSetSummary(ArrayList<Integer> list)

skipWhiteSpace

protected int skipWhiteSpace(int i,
                             String s)

findNextWhiteSpace

protected int findNextWhiteSpace(int i,
                                 String s)

addToSet

protected void addToSet(int val,
                        int end,
                        int incr,
                        int type)
                 throws ParseException

抛出:

ParseException

getSet

TreeSet<Integer> getSet(int type)

getValue

protected ValueSet getValue(int v,
                            String s,
                            int i)

getNumericValue

protected int getNumericValue(String s,
                              int i)

getMonthNumber

protected int getMonthNumber(String s)

getDayOfWeekNumber

protected int getDayOfWeekNumber(String s)

getTimeAfter

public Date getTimeAfter(Date afterTime)

setCalendarHour

protected void setCalendarHour(Calendar cal,
                               int hour)

Advance the calendar to the particular hour paying particular attention to daylight saving problems.

参数:

cal - the calendar to operate on

hour - the hour to set

getTimeBefore

public Date getTimeBefore(Date endTime)

NOT YET IMPLEMENTED: Returns the time before the given time that the CronExpression matches.

getFinalFireTime

public 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)

readObject

private void readObject(ObjectInputStream stream)
                 throws IOException,
                        ClassNotFoundException

抛出:

IOException

ClassNotFoundException

clone

@Deprecated
public Object clone()

已过时。

覆盖:

clone 在类中 Object