org.semanticweb.elk.reasoner
Class Reasoner

java.lang.Object
  org.semanticweb.elk.reasoner.stages.AbstractReasonerState
      org.semanticweb.elk.reasoner.Reasoner

public class Reasoner
extends AbstractReasonerState

The class for querying the results of the reasoning tasks for a given ontology. The input ontology is represented internally by the OntologyIndex object, which is updated by adding or removing ElkAxioms (methods addAxiom() and removeAxiom()). When querying the results of the reasoning tasks, the reasoner will ensure that all necessary reasoning stages, such as consistency checking, are performed. Reasoners are created (and pre-configured) by the ReasonerFactory.

Field Summary

protected boolean	allowFreshEntities Should fresh entities in reasoner queries be accepted (configuration setting).
protected ProgressMonitor	progressMonitor The progress monitor that is used for reporting progress.
protected ReasonerStageExecutor	stageExecutor The executor for various stages of the reasoner

Constructor Summary

protected

Reasoner(AxiomLoader axiomLoader, ReasonerStageExecutor stageExecutor, ExecutorService executor) Constructor.

Method Summary

boolean	getAllowFreshEntities() Get whether fresh entities are allowed.
TaxonomyNode<ElkClass>	getClassNode(ElkClassExpression classExpression) Return the TaxonomyNode for the given ElkClassExpression.
Node<ElkClass>	getEquivalentClasses(ElkClassExpression classExpression) Return the Node containing equivalent classes of the given ElkClassExpression.
protected InstanceNode<ElkClass,ElkNamedIndividual>	getInstanceNode(ElkNamedIndividual elkNamedIndividual) Helper method to get an InstanceNode from the taxonomy.
Set<? extends Node<ElkNamedIndividual>>	getInstances(ElkClassExpression classExpression, boolean direct) Return the (direct or indirect) instances of the given ElkClassExpression as specified by the parameter.
protected int	getNumberOfWorkers()
protected ComputationExecutor	getProcessExecutor()
protected ProgressMonitor	getProgressMonitor()
protected ReasonerStageExecutor	getStageExecutor()
Set<? extends Node<ElkClass>>	getSubClasses(ElkClassExpression classExpression, boolean direct) Return the (direct or indirect) subclasses of the given ElkClassExpression as specified by the parameter.
Set<? extends Node<ElkClass>>	getSuperClasses(ElkClassExpression classExpression, boolean direct) Return the (direct or indirect) superclasses of the given ElkClassExpression as specified by the parameter.
protected TaxonomyNode<ElkClass>	getTaxonomyNode(ElkClass elkClass) Helper method to get a TaxonomyNode from the taxonomy.
protected TypeNode<ElkClass,ElkNamedIndividual>	getTypeNode(ElkClass elkClass) Helper method to get a TypeNode from the taxonomy.
Set<? extends Node<ElkClass>>	getTypes(ElkNamedIndividual elkNamedIndividual, boolean direct) Return the (direct or indirect) types of the given ElkNamedIndividual.
boolean	isSatisfiable(ElkClassExpression classExpression) Check if the given ElkClassExpression is satisfiable, that is, if it can possibly have instances.
void	setAllowFreshEntities(boolean allow) Set if fresh entities should be allowed.
void	setConfigurationOptions(ReasonerConfiguration config) This supposed to be the central place where the reasoner gets its configuration options
void	setNumberOfWorkers(int workerNo) Sets the number of working threads.
void	setProgressMonitor(ProgressMonitor progressMonitor) Set the progress monitor that will be used for reporting progress on all potentially long-running operations.
boolean	shutdown() Tries to shut down the reasoner within 1 minute
boolean	shutdown(long timeout, TimeUnit unit) Tries to shut down the reasoner within the specified time

Methods inherited from class org.semanticweb.elk.reasoner.stages.AbstractReasonerState

clearInterrupt, doneConsistencyCheck, doneInstanceTaxonomy, doneTaxonomy, forceLoading, getAllClasses, getAllNamedIndividuals, getContextMap, getIndexedClassExpressions, getInstanceTaxonomy, getInstanceTaxonomyQuietly, getOntologyIndex, getPropertySaturationMap, getTaxonomy, getTaxonomyQuietly, initClassTaxonomy, initInstanceTaxonomy, interrupt, isAllowIncrementalMode, isInconsistent, isIncrementalMode, isInterrupted, registerAxiomLoader, resetAxiomLoading, setAllowIncrementalMode, setAllowIncrementalTaxonomy, useIncrementalTaxonomy

Methods inherited from class java.lang.Object

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

Field Detail

progressMonitor

protected ProgressMonitor progressMonitor

The progress monitor that is used for reporting progress.

stageExecutor

protected final ReasonerStageExecutor stageExecutor

The executor for various stages of the reasoner

allowFreshEntities

protected boolean allowFreshEntities

Should fresh entities in reasoner queries be accepted (configuration setting). If false, a ElkFreshEntitiesException will be thrown when encountering entities that did not occur in the ontology.

Constructor Detail

Reasoner

protected Reasoner(AxiomLoader axiomLoader,
                   ReasonerStageExecutor stageExecutor,
                   ExecutorService executor)

Constructor. In most cases, Reasoners should be created by the ReasonerFactory.

Method Detail

setProgressMonitor

public void setProgressMonitor(ProgressMonitor progressMonitor)

Set the progress monitor that will be used for reporting progress on all potentially long-running operations.

Parameters:

progressMonitor -

setAllowFreshEntities

public void setAllowFreshEntities(boolean allow)

Set if fresh entities should be allowed. Fresh entities are entities that occur as parameters of reasoner queries without occurring in the loaded ontology. If false, a ElkFreshEntitiesException will be thrown in such cases. If true, the reasoner will answer as if the entity had been declared (but not used in any axiom).

Parameters:

allow -

getAllowFreshEntities

public boolean getAllowFreshEntities()

Get whether fresh entities are allowed. See setAllowFreshEntities(boolean) for details.

Returns:

true if fresh entities are allowed

getNumberOfWorkers

protected int getNumberOfWorkers()

Specified by:

getNumberOfWorkers in class AbstractReasonerState

Returns:

the maximal number of workers that can be used for running concurrent reasoning tasks

setNumberOfWorkers

public void setNumberOfWorkers(int workerNo)

Sets the number of working threads. Shouldn't be used during reasoning.

Parameters:

workerNo -

setConfigurationOptions

public void setConfigurationOptions(ReasonerConfiguration config)

This supposed to be the central place where the reasoner gets its configuration options

Parameters:

config -

getProcessExecutor

protected ComputationExecutor getProcessExecutor()

Specified by:

getProcessExecutor in class AbstractReasonerState

Returns:

the ComputationExecutor that is used for execution of reasoning processes

getStageExecutor

protected ReasonerStageExecutor getStageExecutor()

Specified by:

getStageExecutor in class AbstractReasonerState

Returns:

the ReasonerStageExecutor that is used for executing the stages of the reasoner.

getProgressMonitor

protected ProgressMonitor getProgressMonitor()

Specified by:

getProgressMonitor in class AbstractReasonerState

Returns:

the ProgressMonitor that is used for reporting progress on all potentially long-running operations.

shutdown

public boolean shutdown(long timeout,
                        TimeUnit unit)
                 throws InterruptedException

Tries to shut down the reasoner within the specified time

Parameters:

timeout - the maximum time to wait

unit - the time unit of the timeout argument

Returns:

true if the operation was successful

Throws:

InterruptedException - if the current thread was interrupted

shutdown

public boolean shutdown()
                 throws InterruptedException

Tries to shut down the reasoner within 1 minute

Returns:

true if the operation was successful

Throws:

InterruptedException - if the current thread was interrupted

getTaxonomyNode

protected TaxonomyNode<ElkClass> getTaxonomyNode(ElkClass elkClass)
                                          throws ElkException

Helper method to get a TaxonomyNode from the taxonomy.

Parameters:

elkClass - an ElkClass for which to find a TaxonomyNode

Returns:

the TaxonomyNode for the given ElkClass

Throws:

ElkException

getInstanceNode

protected InstanceNode<ElkClass,ElkNamedIndividual> getInstanceNode(ElkNamedIndividual elkNamedIndividual)
                                                             throws ElkException

Helper method to get an InstanceNode from the taxonomy.

Parameters:

elkNamedIndividual -

Returns:

the InstanceNode for the given ElkNamedIndividual

Throws:

ElkException - if the result cannot be computed

getTypeNode

protected TypeNode<ElkClass,ElkNamedIndividual> getTypeNode(ElkClass elkClass)
                                                     throws ElkException

Helper method to get a TypeNode from the taxonomy.

Parameters:

elkClass -

Returns:

the TypeNode for the given ElkClass

Throws:

ElkException - if the result cannot be computed

getClassNode

public TaxonomyNode<ElkClass> getClassNode(ElkClassExpression classExpression)
                                    throws ElkException

Return the TaxonomyNode for the given ElkClassExpression. Calling of this method may trigger the computation of the taxonomy, if it has not been done yet. If the input is an ElkClass that does not occur in the ontology and fresh entities are not allowed, a ElkFreshEntitiesException will be thrown.

Parameters:

classExpression - the ElkClassExpression for which to return the Node

Returns:

the TaxonomyNode for the given ElkClassExpression

Throws:

ElkException - if the result cannot be computed

getEquivalentClasses

public Node<ElkClass> getEquivalentClasses(ElkClassExpression classExpression)
                                    throws ElkException

Return the Node containing equivalent classes of the given ElkClassExpression. Calling of this method may trigger the computation of the taxonomy, if it has not been done yet.

Parameters:

classExpression - the ElkClassExpression for which to return the Node

Returns:

the set of Node whose members are ElkClasses equivalent to the given ElkClassExpression

Throws:

ElkException - if the result cannot be computed

getSubClasses

public Set<? extends Node<ElkClass>> getSubClasses(ElkClassExpression classExpression,
                                                   boolean direct)
                                            throws ElkException

Return the (direct or indirect) subclasses of the given ElkClassExpression as specified by the parameter. The method returns a set of Nodes, each of which representing an equivalent class of subclasses. Calling of this method may trigger the computation of the taxonomy, if it has not been done yet.

Parameters:

classExpression - the ElkClassExpression for which to return the subclass Nodes

direct - if true, only direct subclasses should be returned

Returns:

the set of Nodes for direct or indirect subclasses of the given ElkClassExpression according to the specified parameter

Throws:

ElkException - if the result cannot be computed

getSuperClasses

public Set<? extends Node<ElkClass>> getSuperClasses(ElkClassExpression classExpression,
                                                     boolean direct)
                                              throws ElkException

Return the (direct or indirect) superclasses of the given ElkClassExpression as specified by the parameter. The method returns a set of Nodes, each of which representing an equivalent class of superclasses. Calling of this method may trigger the computation of the taxonomy, if it has not been done yet.

Parameters:

classExpression - the ElkClassExpression for which to return the superclass Nodes

direct - if true, only direct superclasses are returned

Returns:

the set of Nodes for direct or indirect superclasses of the given ElkClassExpression according to the specified parameter

Throws:

ElkException - if the result cannot be computed

getInstances

public Set<? extends Node<ElkNamedIndividual>> getInstances(ElkClassExpression classExpression,
                                                            boolean direct)
                                                     throws ElkException

Return the (direct or indirect) instances of the given ElkClassExpression as specified by the parameter. The method returns a set of Nodes, each of which representing an equivalent class of instances. Calling of this method may trigger the computation of the realization, if it has not been done yet.

Parameters:

classExpression - the ElkClassExpression for which to return the instances Nodes

direct - if true, only direct instances are returned

Returns:

the set of Nodes for direct or indirect instances of the given ElkClassExpression according to the specified parameter

Throws:

ElkException - if the result cannot be computed

getTypes

public Set<? extends Node<ElkClass>> getTypes(ElkNamedIndividual elkNamedIndividual,
                                              boolean direct)
                                       throws ElkException

Return the (direct or indirect) types of the given ElkNamedIndividual. The method returns a set of Nodes, each of which representing an equivalent class of types. Calling of this method may trigger the computation of the realization, if it has not been done yet.

Parameters:

elkNamedIndividual - the ElkNamedIndividual for which to return the types Nodes

direct - if true, only direct types are returned

Returns:

the set of Nodes for the direct or indirect types of the given ElkNamedIndividual according to the specified parameter

Throws:

ElkException - if the result cannot be computed

isSatisfiable

public boolean isSatisfiable(ElkClassExpression classExpression)
                      throws ElkException

Check if the given ElkClassExpression is satisfiable, that is, if it can possibly have instances. ElkClassExpressions are not satisfiable if they are equivalent to owl:Nothing. A satisfiable ElkClassExpression is also called consistent or coherent. Calling of this method may trigger the computation of the taxonomy, if it has not been done yet.

Parameters:

classExpression - the ElkClassExpression for which to check satisfiability

Returns:

true if the given input is satisfiable

Throws:

ElkException - if the result cannot be computed