Package com.orchestranetworks.scheduler

Class ScheduledTask

java.lang.Object

com.orchestranetworks.scheduler.ScheduledTask

public abstract class ScheduledTask
extends Object

Task definition to be executed by the EBX® task scheduler. To define a task, a concrete class extending this abstract class must be implemented. This concrete class must have a public no-argument constructor.

Life cycle

A ScheduledTask is instantiated each time a task definition is validated by EBX® and each time the execution is fired by the scheduler.

Configuration

A ScheduledTask can be parameterized using JavaBean specifications (getters and setters).

Supported parameter types are:

• boolean
• int
• java.lang.Boolean
• java.lang.Integer
• java.math.BigDecimal
• java.lang.String
• java.util.Date
• java.net.URI
• java.net.URL

Constructor Summary

Constructors

Constructor	Description
ScheduledTask()

Method Summary

Modifier and Type	Method	Description
abstract void	execute(ScheduledExecutionContext aContext)	Executes the current task.
void	handleBeforeInterrupting(ScheduledExecutionContext aContext)	When a task interruption has been requested through EBX® administration, this method provides the opportunity to perform actions before actually interrupting the task execution.
void	handleBeforePausing(ScheduledExecutionContext aContext)	When a pause has been requested through EBX® administration, this method provides the opportunity to perform actions before entering the pause state.
void	handleBeforeResuming(ScheduledExecutionContext aContext)	When the administrator requests to resume a paused schedule task, this method provides the opportunity to perform actions before the task resumes execution.
boolean	isInterruptable()	If true, the current task can be interrupted through EBX® administration.
boolean	isPausable()	If true, the current task can be paused (and resumed) through EBX® administration.
void	validate(ValueContextForValidation aValidationContext)	Validates the current task configuration.

Methods inherited from class java.lang.Object

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

Constructor Details

ScheduledTask

public ScheduledTask()

Method Details

validate

public void validate(ValueContextForValidation aValidationContext)

Validates the current task configuration.

Called at:

• task configuration in Administration > Task scheduler > Tasks,
• task instantiation in the scheduler.

Default implementation does nothing. To be overridden if specific checks have to be done.

execute

public abstract void execute(ScheduledExecutionContext aContext)
                      throws OperationException,
ScheduledTaskInterruption

Executes the current task.

The implementation of this method should not try to catch the interruption signal ScheduledTaskInterruption.

Throws:

OperationException

ScheduledTaskInterruption

See Also:

• ProgrammaticService

handleBeforeInterrupting

public void handleBeforeInterrupting(ScheduledExecutionContext aContext)
                              throws OperationException

When a task interruption has been requested through EBX® administration, this method provides the opportunity to perform actions before actually interrupting the task execution.

For instance, this may be overridden to release resources by closing open files and database connections.

In order to enable interruptions, the method isInterruptable() must be overridden. Also, to allow interrupting, the execution method must invoke the method ScheduledExecutionContext.handleExecutionState() where an interrupt would be acceptable.

Default implementation does nothing.

Throws:

OperationException

See Also:

• isInterruptable()
• ScheduledExecutionContext.handleExecutionState()

handleBeforePausing

public void handleBeforePausing(ScheduledExecutionContext aContext)
                         throws OperationException

When a pause has been requested through EBX® administration, this method provides the opportunity to perform actions before entering the pause state.

For instance, this may be overridden to release resources by closing open files and database connections.

In order to enable pauses, the method isPausable() must be overridden. Also, to allow pausing, the execution method must invoke the method ScheduledExecutionContext.handleExecutionState() where a pause would be acceptable.

Default implementation does nothing. If an OperationException is thrown, the task execution is interrupted.

Throws:

OperationException

See Also:

• isPausable()
• ScheduledExecutionContext.handleExecutionState()

handleBeforeResuming

public void handleBeforeResuming(ScheduledExecutionContext aContext)
                          throws OperationException

When the administrator requests to resume a paused schedule task, this method provides the opportunity to perform actions before the task resumes execution.

For instance, this may be overridden to acquire resources that were released after the pause by re-opening files and JDBC connections.

If an OperationException is thrown, the task execution is interrupted.

Default implementation does nothing. To be overridden if a specific behavior is required.

Throws:

OperationException

See Also:

• handleBeforePausing(ScheduledExecutionContext)

isInterruptable

public boolean isInterruptable()

If true, the current task can be interrupted through EBX® administration.

Default implementation returns false.

See Also:

• handleBeforeInterrupting(ScheduledExecutionContext)

isPausable

public boolean isPausable()

If true, the current task can be paused (and resumed) through EBX® administration.

Default implementation returns false.

See Also:

• handleBeforePausing(ScheduledExecutionContext)
• handleBeforeResuming(ScheduledExecutionContext)