bdi4jade.belief

Class BeliefBase

java.lang.Object

bdi4jade.belief.BeliefBase

All Implemented Interfaces:

java.io.Serializable

public class BeliefBase
extends java.lang.Object
implements java.io.Serializable

This class represents a belief base of a capability. It aggregates its knowledge.

Author:

Ingrid Nunes

See Also:

Serialized Form

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BeliefBase() The default constructor.
	BeliefBase(Capability capability) Creates a belief base associated with a capability.
	BeliefBase(Capability capability, java.util.Set<Belief<?>> beliefs) Creates a belief base associated with a capability and adds the beliefs in the provided belief set as the initial beliefs of this belief base.

Method Summary

Methods

Modifier and Type	Method and Description
void	addBelief(Belief<?> belief) Adds a belief to the belief base.
void	addBeliefListener(BeliefListener beliefListener) Adds a belief listener to be notified about changes in the belief base.
void	addOrUpdateBelief(Belief<?> belief) Adds a belief to the belief base.
java.util.Collection<Belief<?>>	getAllBeliefs() Gets all beliefs of this belief base and the belief bases of the whole-capabilities of the capability that this belief base belongs to.
Belief<?>	getBelief(java.lang.String name) Retrieves a belief from the belief base.
java.util.Set<BeliefListener>	getBeliefListeners() Returns all the current belief listeners of this belief base.
java.util.Set<Belief<?>>	getBeliefs() Gets all beliefs of this specific belief base.
java.util.List<java.lang.Object>	getBeliefValues() Returns a list of all belief values from this belief base.
Capability	getCapability() Returns the capability with which this belief base is associated.
boolean	hasBelief(java.lang.String name) Checks whether a belief is part of the belief base.
protected void	notifyBeliefChanged(BeliefEvent beliefChanged) Notifies the capability associated with this belief base that a belief was modified.
Belief<?>	removeBelief(java.lang.String name) Removes a belief from the belief base.
void	removeBeliefListener(BeliefListener beliefListener) Removes a belief listener.
protected void	setCapability(Capability capability) Associates a capability with this belief base.
int	size() Gets the size of this specific belief base (the number of beliefs).
java.lang.String	toString() Returns this belief base as a string in the form: "Belief base of Capability ID = [ BELIEFS ]".
boolean	updateBelief(java.lang.String name, java.lang.Object value) Updates the value of a belief in the belief base.

Methods inherited from class java.lang.Object

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

Constructor Detail

BeliefBase

protected BeliefBase()

The default constructor. It should be only used if persistence frameworks are used.

BeliefBase

public BeliefBase(Capability capability)

Creates a belief base associated with a capability.

Parameters:

capability - the capability to which this belief base belongs.

BeliefBase

public BeliefBase(Capability capability,
          java.util.Set<Belief<?>> beliefs)

Creates a belief base associated with a capability and adds the beliefs in the provided belief set as the initial beliefs of this belief base.

Parameters:

capability - the capability to which this belief base belongs.

beliefs - the initial beliefs.

Method Detail

addBelief

public void addBelief(Belief<?> belief)

Adds a belief to the belief base.

Parameters:

belief - the belief to be added.

addBeliefListener

public void addBeliefListener(BeliefListener beliefListener)

Adds a belief listener to be notified about changes in the belief base.

Parameters:

beliefListener - the listener to be added.

addOrUpdateBelief

public void addOrUpdateBelief(Belief<?> belief)

Adds a belief to the belief base. It updates the belief value, if it already exists.

Parameters:

belief - the belief to be added or updated.

getAllBeliefs

public java.util.Collection<Belief<?>> getAllBeliefs()

Gets all beliefs of this belief base and the belief bases of the whole-capabilities of the capability that this belief base belongs to.

Returns:

the beliefs of this capability and all of its whole-capabilities.

getBelief

public Belief<?> getBelief(java.lang.String name)

Retrieves a belief from the belief base. If this belief base does not contain it, the method checks whole-capabilities' belief base recursively.

Parameters:

name - the name of the belief to be retrieved.

Returns:

the belief, or null if no belief is found.

getBeliefListeners

public java.util.Set<BeliefListener> getBeliefListeners()

Returns all the current belief listeners of this belief base.

Returns:

the belief listeners.

getBeliefs

public java.util.Set<Belief<?>> getBeliefs()

Gets all beliefs of this specific belief base.

Returns:

the beliefs

getBeliefValues

public java.util.List<java.lang.Object> getBeliefValues()

Returns a list of all belief values from this belief base.

Returns:

the beliefValues

getCapability

public Capability getCapability()

Returns the capability with which this belief base is associated.

Returns:

the capability.

hasBelief

public boolean hasBelief(java.lang.String name)

Checks whether a belief is part of the belief base. If this belief base does not contain it, the method checks whole-capabilities' belief base recursively.

Parameters:

name - the belief to be checked

Returns:

true if the belief base contains the belief.

notifyBeliefChanged

protected void notifyBeliefChanged(BeliefEvent beliefChanged)

Notifies the capability associated with this belief base that a belief was modified. It also recursively notifies belief listeners of part capabilities.

Parameters:

beliefChanged - the belief that was changed

removeBelief

public Belief<?> removeBelief(java.lang.String name)

Removes a belief from the belief base. If this belief base does not contain it, the method checks whole-capabilities' belief base recursively to remove this belief..

Parameters:

name - the name of the belief to be removed.

Returns:

the belief was removed, null if it is not part of the belief base.

removeBeliefListener

public void removeBeliefListener(BeliefListener beliefListener)

Removes a belief listener.

Parameters:

beliefListener - the listener to be removed.

setCapability

protected void setCapability(Capability capability)

Associates a capability with this belief base. Ideally, the capability should be final and initialized in the constructor. This method should be only used if persistence frameworks are used.

Parameters:

capability - the capability to set.

size

public int size()

Gets the size of this specific belief base (the number of beliefs).

Returns:

the size of this belief base.

toString

public java.lang.String toString()

Returns this belief base as a string in the form: "Belief base of Capability ID = [ BELIEFS ]".

Overrides:

toString in class java.lang.Object

Returns:

the string representation of this belief base.

See Also:

Object.toString()

updateBelief

public boolean updateBelief(java.lang.String name,
                   java.lang.Object value)

Updates the value of a belief in the belief base. In case the belief is not present in the belief base (of in its whole-capabilities' belief bases), nothing is performed and the method returns false. If the type of the new value being provided does not match the current type, the method still subscribes the previous value.

Parameters:

name - the belief to be updated.

value - the new value to the belief.

Returns:

true if the belief was updated.