com.dvt.app.threadworks
Class Scheduler

java.lang.Object
  |
  +--java.lang.Thread
        |
        +--com.dvt.app.threadworks.Scheduler

All Implemented Interfaces:

java.lang.Runnable

public class Scheduler

extends java.lang.Thread

A Java-based scheduler. Scheduler supports time-based dependencies and custom dependancies. Any task that is runnable can be scheduled.

Internally, Scheduler uses a TaskManager(@see TaskManager). Therefore, it benefits from the support infrastructure that TaskManager provides.

Only one Scheduler per JVM is allowed. If a custom environment for Scheduler is needed, place the Scheduler instantiation in the start-up sequence of your application BEFORE and Schedulers and TaskManagers are defined.

It is recommended, but not required, that scheduled tasks implement Describable (@see com.dvt.app.common.Describable) as well as Runnable. Describables are capable of producing textual descriptions of themselves. If the task excepts or exceeds its maximum allowed run time, Scheduler will log the probleem. If the task is Describable, Scheduler will log the tasks description as well. This facilitates support.

Copyright: Delta Vortex Technologies, 2001.

Field Summary

static long	DAILY_INTERVAL Daily interval
static int	DEFAULT_DIAGNOSTIC_REPORTING_INTERVAL Default interval for reporting diagnostics in milliseconds.
static java.lang.String	DEFAULT_LOG_LABEL Default log label
static int	DEFAULT_MAX_TASK_TIME_ALLOWED Default maximum time allowed on 1 task in milliseconds.
static int	DEFAULT_NBR_CONCURRENT_TASKS Default number of concurrent scheduled tasks
static java.lang.String	DEFAULT_PROP_FILE_NAME Default properties file name
static long	DEFAULT_SPIN_COUNT Default spin count
static long	HOURLY_INTERVAL Hourly Interval
static long	WEEKLY_INTERVAL Weekly Interval

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

Scheduler(java.lang.String propertiesFileName)
Starts the Scheduler with a custom environment.

Scheduler(TaskManagerEnvironment env, long spinCount)
Starts the Scheduler with a custom environment.

Method Summary

static void	logDiagnostics() Will log Scheduler diagnostics.
static boolean	remove(java.lang.Runnable task) Removes a previously scheduled task
static boolean	remove(java.lang.Runnable task, long interval) Removes a previously scheduled task
void	run() Used internally by the Scheduler.
static void	schedule(java.lang.Runnable task, java.util.GregorianCalendar dateTime) Schedules a one-time task execution starting at the specified date and time.
static void	schedule(java.lang.Runnable task, java.util.GregorianCalendar dateTime, DependencyEventListener listener) Schedules a one-time task execution starting at the specified date and time.
static void	schedule(java.lang.Runnable task, java.util.GregorianCalendar dateTime, long interval) Schedules a recurring task starting at the specified date and time.
static void	schedule(java.lang.Runnable task, java.util.GregorianCalendar dateTime, long interval, DependencyEventListener listener) Schedules a recurring task starting at the specified date and time.
static void	schedule(java.lang.Runnable task, long delay) Schedules a one-time execution of a task starting after an initial delay.
static void	schedule(java.lang.Runnable task, long delay, DependencyEventListener listener) Schedules a one-time execution of a task starting after an initial delay.
static void	schedule(java.lang.Runnable task, long delay, long interval) Schedules a recurring task starting after an initial delay.
static void	schedule(java.lang.Runnable task, long delay, long interval, DependencyEventListener listener) Schedules a recurring task starting after an initial delay.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getContextClassLoader, getName, getPriority, getThreadGroup, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setName, setPriority, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Field Detail

DEFAULT_SPIN_COUNT

public static final long DEFAULT_SPIN_COUNT

Default spin count

DEFAULT_PROP_FILE_NAME

public static final java.lang.String DEFAULT_PROP_FILE_NAME

Default properties file name

DEFAULT_NBR_CONCURRENT_TASKS

public static final int DEFAULT_NBR_CONCURRENT_TASKS

Default number of concurrent scheduled tasks

DEFAULT_DIAGNOSTIC_REPORTING_INTERVAL

public static final int DEFAULT_DIAGNOSTIC_REPORTING_INTERVAL

Default interval for reporting diagnostics in milliseconds.

DEFAULT_MAX_TASK_TIME_ALLOWED

public static final int DEFAULT_MAX_TASK_TIME_ALLOWED

Default maximum time allowed on 1 task in milliseconds.

DEFAULT_LOG_LABEL

public static final java.lang.String DEFAULT_LOG_LABEL

Default log label

HOURLY_INTERVAL

public static final long HOURLY_INTERVAL

Hourly Interval

DAILY_INTERVAL

public static final long DAILY_INTERVAL

Daily interval

WEEKLY_INTERVAL

public static final long WEEKLY_INTERVAL

Weekly Interval

Constructor Detail

Scheduler

public Scheduler(java.lang.String propertiesFileName)
          throws ThreadWorksException

Starts the Scheduler with a custom environment.

Parameters:

Properties -

Scheduler

public Scheduler(TaskManagerEnvironment env,
                 long spinCount)
          throws ThreadWorksException

Starts the Scheduler with a custom environment.

Parameters:

Environment - for internal TaskManager

time - interval in millis that the schedule is examined.

Method Detail

run

public void run()

Used internally by the Scheduler.

Overrides:

run in class java.lang.Thread

schedule

public static void schedule(java.lang.Runnable task,
                            long delay)
                     throws ThreadWorksException

Schedules a one-time execution of a task starting after an initial delay.

Parameters:

task - to be scheduled

run - delay in millis

schedule

public static void schedule(java.lang.Runnable task,
                            long delay,
                            DependencyEventListener listener)
                     throws ThreadWorksException

Schedules a one-time execution of a task starting after an initial delay.

Parameters:

task - to be scheduled

run - delay in millis

dependency - listener

schedule

public static void schedule(java.lang.Runnable task,
                            long delay,
                            long interval)
                     throws ThreadWorksException

Schedules a recurring task starting after an initial delay.

Parameters:

task - to be scheduled

initial - run delay in millis

run - interval used after initial run

schedule

public static void schedule(java.lang.Runnable task,
                            long delay,
                            long interval,
                            DependencyEventListener listener)
                     throws ThreadWorksException

Schedules a recurring task starting after an initial delay.

Parameters:

task - to be scheduled

initial - run delay in millis

run - interval used after initial run

dependency - listener

schedule

public static void schedule(java.lang.Runnable task,
                            java.util.GregorianCalendar dateTime)
                     throws ThreadWorksException

Schedules a one-time task execution starting at the specified date and time.

Parameters:

task - to be scheduled

date - and time of initial run

schedule

public static void schedule(java.lang.Runnable task,
                            java.util.GregorianCalendar dateTime,
                            DependencyEventListener listener)
                     throws ThreadWorksException

Schedules a one-time task execution starting at the specified date and time.

Parameters:

task - to be scheduled

date - and time of initial run

dependency - listener

schedule

public static void schedule(java.lang.Runnable task,
                            java.util.GregorianCalendar dateTime,
                            long interval)
                     throws ThreadWorksException

Schedules a recurring task starting at the specified date and time.

Parameters:

task - to be scheduled

date - and time of initial run

run - interval used after initial run

schedule

public static void schedule(java.lang.Runnable task,
                            java.util.GregorianCalendar dateTime,
                            long interval,
                            DependencyEventListener listener)
                     throws ThreadWorksException

Schedules a recurring task starting at the specified date and time.

Parameters:

task - to be scheduled

date - and time of initial run

run - interval used after initial run

dependency - listener

remove

public static boolean remove(java.lang.Runnable task)
                      throws ThreadWorksException

Removes a previously scheduled task

Parameters:

task - to be removed

Returns:

indicator if a scheduled task was removed.

remove

public static boolean remove(java.lang.Runnable task,
                             long interval)
                      throws ThreadWorksException

Removes a previously scheduled task

Parameters:

task - to be removed

interval - used in original scheduling

Returns:

indicator if scheduled task at specified interval was removed

logDiagnostics

public static void logDiagnostics()
                           throws ThreadWorksException

Will log Scheduler diagnostics.