org.objectledge.scheduler
Class CronSchedule

java.lang.Object
  org.objectledge.scheduler.CronSchedule

All Implemented Interfaces:

Schedule

public class CronSchedule
extends Object
implements Schedule

A schedule that follows the configuration syntax of Unix cron utility.

The configuration grammar:

 schedule_config := ( ( minute hour day month weekday ) | special )
 special := ( "@reboot" | "@yearly" | "@annually" | "@monthly" | "@weekly" |
   "@daily" | "@midnight" | "@hourly" )
 minute := value_spec
 hour := value_spec
 day := value_spec
 month := ( value_spec | month_name )
 weekday := ( value_spec | weekday_name )
 month_name := ( "jan" | "feb" | "mar" | "apr" | "may" | "jun" |
   "jul" | "aug" | "sep" | "oct" | "nov" | "dec" )
 weekday_name := ( "mon" | "tue" | "wed" | "thu" | "fri" | "sat" | "sun" )
 value_spec := ( "*" | list_of_values )
 list_of_values := ( value_or_range ( "," value_or_range )* )
 value_or_range := ( number | range )
 range := number "-" number [ "/" number ]
 number := LEXICAL( [0-9]+ )
 

Configuration syntax is compatible with Paul Vixie's cron, version 3.0.

Field Summary

private String	config The textual configuration form.
private static int	DAY_OF_MONTH index of day field.
private static int	DAY_OF_WEEK index of weekday field.
protected String	eol The end of line string for this machine.
private static int	HOUR_OF_DAY index of hour field.
private I18n	i18n I18n component
private static int	MINUTE index of minute field.
private static int	MONTH index of month field.
private int[][]	schedule The parserd schedule data.
static String	TYPE The schedule type.

Constructor Summary

CronSchedule(I18n i18n)
Constructor.

Method Summary

protected String	addEscapes(String str) Used to convert raw characters to their escaped version when these raw version cannot be used as part of an ASCII string literal.
boolean	atStartup() Checks if the job should be run at the very startup of the scheduler.
private void	computeDay(Calendar nextRun)
private void	computeHour(Calendar nextRun)
private void	computeMinute(Calendar nextRun)
private void	computeMonth(Calendar nextRunDOM)
String	getConfig() Return the schedule configuration.
Date	getNextRunTime(Date currentTime, Date lastRunTime) Calculates the time of the job's next run.
String	getType() Returns the name of the schedule type.
void	init(AbstractScheduler scheduler, String config) Initialize the schedule.
private String	localizeParseException(ParseException ex) Create a localized message out of ParseException object.
private String	localizeValueOutOrRangeException(ValueOutOfRangeException ex) Create a localized message out of ParseException object.
void	setConfig(String config) Sets the schedule configuration.

Methods inherited from class java.lang.Object

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

Field Detail

MINUTE

private static final int MINUTE

index of minute field.

See Also:

Constant Field Values

HOUR_OF_DAY

private static final int HOUR_OF_DAY

index of hour field.

See Also:

Constant Field Values

DAY_OF_MONTH

private static final int DAY_OF_MONTH

index of day field.

See Also:

Constant Field Values

MONTH

private static final int MONTH

index of month field.

See Also:

Constant Field Values

DAY_OF_WEEK

private static final int DAY_OF_WEEK

index of weekday field.

See Also:

Constant Field Values

TYPE

public static final String TYPE

The schedule type.

See Also:

Constant Field Values

config

private String config

The textual configuration form.

schedule

private int[][] schedule

The parserd schedule data.

i18n

private I18n i18n

I18n component

eol

protected String eol

The end of line string for this machine.

Constructor Detail

CronSchedule

public CronSchedule(I18n i18n)

Constructor.

Parameters:

i18n - the i18n component.

Method Detail

init

public void init(AbstractScheduler scheduler,
                 String config)
          throws InvalidScheduleException

Initialize the schedule.

Specified by:

init in interface Schedule

Parameters:

scheduler - the scheduler.

config - the configuration.

Throws:

InvalidScheduleException - if the specification is invalid.

getType

public String getType()

Returns the name of the schedule type.

Specified by:

getType in interface Schedule

Returns:

the name of the schedule type.

getConfig

public String getConfig()

Return the schedule configuration.

The format of the string is dependant on the nature of the schedule.

Specified by:

getConfig in interface Schedule

Returns:

the schedule configuration.

setConfig

public void setConfig(String config)
               throws InvalidScheduleException

Sets the schedule configuration.

The format of the string is dependant on the nature of the schedule.

Specified by:

setConfig in interface Schedule

Parameters:

config - schedule configuration.

Throws:

InvalidScheduleException - if the specification is invalid

atStartup

public boolean atStartup()

Checks if the job should be run at the very startup of the scheduler.

Specified by:

atStartup in interface Schedule

Returns:

true if the job should be run during the startup of the scheduler.

getNextRunTime

public Date getNextRunTime(Date currentTime,
                           Date lastRunTime)

Calculates the time of the job's next run.

Specified by:

getNextRunTime in interface Schedule

Parameters:

currentTime - the current time.

lastRunTime - the last time the job was run, or null if unknown.

Returns:

job's next execution time of null for never again.

computeMonth

private void computeMonth(Calendar nextRunDOM)

computeDay

private void computeDay(Calendar nextRun)

computeHour

private void computeHour(Calendar nextRun)

computeMinute

private void computeMinute(Calendar nextRun)

localizeParseException

private String localizeParseException(ParseException ex)

Create a localized message out of ParseException object.

Parameters:

ex - the exception.

localizeValueOutOrRangeException

private String localizeValueOutOrRangeException(ValueOutOfRangeException ex)

Create a localized message out of ParseException object.

Parameters:

ex - the exception.

addEscapes

protected String addEscapes(String str)

Used to convert raw characters to their escaped version when these raw version cannot be used as part of an ASCII string literal.

This method was copied from JavaCC generated code.

Parameters:

str - input string.

Returns:

string with escaped sepcial characters.