br.pucrio.inf.les.bdijade.plan
Class PlanInstance

java.lang.Object
  br.pucrio.inf.les.bdijade.plan.PlanInstance

All Implemented Interfaces:

GoalListener, java.util.EventListener

public class PlanInstance
extends java.lang.Object
implements GoalListener

This class represents a plan that has been instantiated to be executed, with an associated plan body (a behavior).

Author:

ingrid

Nested Class Summary

static class

PlanInstance.EndState This enumuration represents the possible end states of a plan execution.

Field Summary

private jade.core.behaviours.Behaviour	behaviour
private PlanInstance.EndState	endState
private java.util.List<GoalFinishedEvent>	goalEventQueue
private Intention	intention
private Plan	plan
private java.util.List<Goal>	subgoals

Constructor Summary

PlanInstance(Plan plan, Intention intention)
Creates a new plan instance.

Method Summary

void	dispatchGoal(Goal goal) Dispatches a goal to be achieved.
void	dispatchSubgoal(Goal subgoal) Dispatches a subgoal to be achieved.
void	dispatchSubgoalAndListen(Goal subgoal) Dispatches a subgoal to be achieved and registers itself as a listener to receive a notification of the end of execution of the goal.
private void	dropSubgoals() Drops all current subgoals dispatched by this plan.
BeliefBase	getBeliefBase() Returns the belief base of the capability.
PlanInstance.EndState	getEndState() Returns the end state of plan.
Goal	getGoal() Returns the goal to be achieved by this plan instance.
GoalFinishedEvent	getGoalEvent() Returns a goal event from the queue.
GoalFinishedEvent	getGoalEvent(boolean block) Returns a goal event from the queue.
private GoalFinishedEvent	getGoalEvent(boolean block, long ms) Returns a goal event from the queue.
GoalFinishedEvent	getGoalEvent(long ms) Returns a goal event from the queue.
Plan	getPlan() Returns the Plan that is associated with this plan instance.
void	goalPerformed(GoalEvent event) Notifies the listener that the goal was performed.
void	startPlan() Starts the plan body, a Behaviour, associated with this plan.
void	stopPlan() Stops the plan body, a Behaviour, associated with this plan.

Methods inherited from class java.lang.Object

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

Field Detail

behaviour

private final jade.core.behaviours.Behaviour behaviour

endState

private PlanInstance.EndState endState

goalEventQueue

private final java.util.List<GoalFinishedEvent> goalEventQueue

intention

private final Intention intention

plan

private final Plan plan

subgoals

private final java.util.List<Goal> subgoals

Constructor Detail

PlanInstance

public PlanInstance(Plan plan,
                    Intention intention)
             throws PlanInstantiationException

Creates a new plan instance. It is associated with a plan definition ( Plan) and an Intention. It creates an instance of the plan body defined in the plan and throws an exception if an error occurs in this process.

Parameters:

plan - the plan associated this this plan instance.

intention - the intention that this plan instance have to achieve.

Throws:

PlanBodyInstantiationException - in an error occurred during the instantiation.

PlanInstantiationException

Method Detail

dispatchGoal

public void dispatchGoal(Goal goal)

Dispatches a goal to be achieved.

Parameters:

goal - the goal to be dispatched.

dispatchSubgoal

public void dispatchSubgoal(Goal subgoal)

Dispatches a subgoal to be achieved.

Parameters:

subgoal - the subgoal to be dispatched.

dispatchSubgoalAndListen

public void dispatchSubgoalAndListen(Goal subgoal)

Dispatches a subgoal to be achieved and registers itself as a listener to receive a notification of the end of execution of the goal.

Parameters:

subgoal - the subgoal to be dispatched.

dropSubgoals

private void dropSubgoals()

Drops all current subgoals dispatched by this plan.

getBeliefBase

public BeliefBase getBeliefBase()

Returns the belief base of the capability.

Returns:

the belief base containing the beliefs.

getEndState

public PlanInstance.EndState getEndState()

Returns the end state of plan. A null value means that the plan is still in execution. If the plan body has come to a successful end state, it invokes the method to set the output parameters of the goal, in case the plan body implements the OutputPlanBody interface (this is invoked only once). If the plan body has come to a failed state, it sets all of its subgoals as no longer desired.

Returns:

the end state of the plan.

getGoal

public Goal getGoal()

Returns the goal to be achieved by this plan instance.

Returns:

the goal.

getGoalEvent

public GoalFinishedEvent getGoalEvent()

Returns a goal event from the queue. If the queue is empty, the behavior associated with this plan instance is blocked.

Returns:

the goal event or null if the queue is empty.

getGoalEvent

public GoalFinishedEvent getGoalEvent(boolean block)

Returns a goal event from the queue. If the queue is empty, the behavior associated with this plan instance is going to be blocked if the parameter passed to this method is true.

Parameters:

block - true if the behavior must be blocked if the queue is empty.

Returns:

the goal event or null if the queue is empty.

getGoalEvent

private GoalFinishedEvent getGoalEvent(boolean block,
                                       long ms)

Returns a goal event from the queue. If the block parameter is true, the behavior associated with this plan instance is going to be blocked if the queue is empty according to the specified milliseconds. specified milliseconds. If the time is lower then zero, the behavior is going to be blocked until an event happens (Behaviour.block()).

Parameters:

block - true if the behavior must be blocked if the queue is empty.

ms - the maximum amount of time that the behavior must be blocked.

Returns:

the goal event or null if the queue is empty.

getGoalEvent

public GoalFinishedEvent getGoalEvent(long ms)

Returns a goal event from the queue. If the queue is empty, the behavior associated with this plan instance is going to be blocked for the specified milliseconds.

Parameters:

ms - the maximum amount of time that the behavior must be blocked.

Returns:

the goal event or null if the queue is empty.

getPlan

public Plan getPlan()

Returns the Plan that is associated with this plan instance.

Returns:

the plan.

goalPerformed

public void goalPerformed(GoalEvent event)

Description copied from interface: GoalListener

Notifies the listener that the goal was performed.

Specified by:

goalPerformed in interface GoalListener

Parameters:

event - the performed goal event.

See Also:

GoalListener.goalPerformed(br.pucrio.inf.les.bdijade.event.GoalEvent)

startPlan

public void startPlan()

Starts the plan body, a Behaviour, associated with this plan.

stopPlan

public void stopPlan()

Stops the plan body, a Behaviour, associated with this plan. If the body implements the DisposablePlanBody, it invokes the method to about the plan body, so it can perform finalizations.