Interface IOntologyBackend

All Superinterfaces:
IServiceProvider
All Known Implementing Classes:
OpenRobotsOntology

public interface IOntologyBackend extends IServiceProvider
This interface describes the abstract behaviour of an ontology backend. It presents the list of operation the "knowledge store" should provide to be used with the ontology server.
  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    add(com.hp.hpl.jena.rdf.model.Statement statement, MemoryProfile memProfile, boolean safe)
    Deprecated.
    boolean
    add(Set<com.hp.hpl.jena.rdf.model.Statement> statements, MemoryProfile memProfile, boolean safe)
    Adds a set of new statements (assertion) to the ontology.
    boolean
    check(com.hp.hpl.jena.rdf.model.Statement statement)
    Checks if a statement is asserted or can be inferred from the ontology.
    boolean
    Checks if a pattern represented as a partial statement matches at least one asserted of inferred statement.
    For instance: A pattern like [?object rdf:type Bottle] would match all instances of the class Bottle. [anAgent sees ?something] would match all objects seen by instance "anAgent".
    boolean
    Performs a consistency validation against the ontology.
    boolean
    checkConsistency(Set<com.hp.hpl.jena.rdf.model.Statement> statements)
    Checks a set of statements (or partial statements) are not inconsistent with the current model.
    void
    clear(PartialStatement partialStmt)
    Remove all statements matching the partial statement.
    void
    Removes one specific event watcher.
    void
    Removes all registered event watchers for this model.
    void
    Closes the model
    This static method acts as a PartialStatement factory.
    com.hp.hpl.jena.ontology.OntProperty
    createProperty(String lex_property)
    Helper to create a
    invalid reference
    property
    attached at the current OpenRobotOntology by mapping the method to the underlying ontology model.
    This is a shortcut for OpenRobotOntology.getModel().createProperty(Namespaces.format(lex_property))
    com.hp.hpl.jena.ontology.OntResource
    createResource(String lex_resource)
    Helper to create a
    invalid reference
    resource
    attached at the current OpenRobotOntology by mapping the method to the underlying ontology model.
    This is a shortcut for OpenRobotOntology.getModel().createResource(Namespaces.format(lex_resource)).
    com.hp.hpl.jena.rdf.model.Statement
    This static method acts as a Statement factory.
    Set<com.hp.hpl.jena.rdf.model.RDFNode>
    find(String varName, Set<PartialStatement> statements, Set<String> filters)
    Tries to identify a resource given a set of partially defined statements (plus optional restrictions) about this resource.
    Set<com.hp.hpl.jena.ontology.OntClass>
    getClassesOf(com.hp.hpl.jena.ontology.OntResource individual, boolean onlyDirect)
     
    Set<com.hp.hpl.jena.ontology.OntResource>
    getInstancesOf(com.hp.hpl.jena.ontology.OntClass type, boolean onlyDirect)
     
    com.hp.hpl.jena.ontology.OntModel
    Returns the underlying Jena ontology model.
    com.hp.hpl.jena.ontology.OntResource
    getResource(String lex_resource)
    Try to retrieve a resource from the ontology, based on its lexical form.
    Set<com.hp.hpl.jena.ontology.OntClass>
    getSubclassesOf(com.hp.hpl.jena.ontology.OntClass type, boolean onlyDirect)
     
    com.hp.hpl.jena.rdf.model.Model
    getSubmodel(com.hp.hpl.jena.rdf.model.Resource node)
    Returns the set of inferred and asserted statement involving a resource as a Jena Model..
    Set<com.hp.hpl.jena.ontology.OntClass>
    getSuperclassesOf(com.hp.hpl.jena.ontology.OntClass type, boolean onlyDirect)
     
    Return the list of event types implemented (hence usable) by this backend.
    Returns the set of all [id, type, label] (with type one of INSTANCE, CLASS, OBJECT_PROPERTY, DATATYPE_PROPERTY, UNDEFINED) of concepts whose labels or id match the given parameter.
    Returns the set of all id of concepts whose labels or ids match the given parameter and of the given type.
    Set<com.hp.hpl.jena.rdf.model.RDFNode>
    query(String key, String query)
    Performs a SPARQL query on the OpenRobots ontology.
    For instance:
    void
    Allows to register several events providers (typically, one by underlying middleware) which in turn provide access to watchers.
    void
    remove(com.hp.hpl.jena.rdf.model.Statement stmt)
    Deprecated.
    void
    remove(Set<com.hp.hpl.jena.rdf.model.Statement> stmts)
    Removes a set of statements from the ontology.
    void
    save(String path)
    Saves the in-memory ontology model to a RDF/XML file.
    long
    Returns the number of statements in the model.
    void
    'Step' the model.
    void
    update(Set<com.hp.hpl.jena.rdf.model.Statement> stmts)
    Update the value of a property.
  • Method Details

    • createProperty

      com.hp.hpl.jena.ontology.OntProperty createProperty(String lex_property)
      Helper to create a
      invalid reference
      property
      attached at the current OpenRobotOntology by mapping the method to the underlying ontology model.
      This is a shortcut for OpenRobotOntology.getModel().createProperty(Namespaces.format(lex_property))
      Parameters:
      lex_property - the lexical form of the property (eg "rdf:type").
      Returns:
      the corresponding Jena property.
      See Also:
      • invalid reference
        com.hp.hpl.jena.rdf.model.OntModel#createOntProperty(String)
    • createResource

      com.hp.hpl.jena.ontology.OntResource createResource(String lex_resource)
      Helper to create a
      invalid reference
      resource
      attached at the current OpenRobotOntology by mapping the method to the underlying ontology model.
      This is a shortcut for OpenRobotOntology.getModel().createResource(Namespaces.format(lex_resource)). If a resource with the same lexical form already exist, it is reused. The getResource(String) method can be used to retrieve resource without creating a new one if it doesn't exist.
      Parameters:
      lex_resource - the lexical form of the resource.
      Returns:
      the corresponding Jena resource.
      See Also:
      • getResource(String)
      • invalid reference
        com.hp.hpl.jena.rdf.model.OntModel#createOntResource(String)
    • getResource

      com.hp.hpl.jena.ontology.OntResource getResource(String lex_resource) throws com.hp.hpl.jena.shared.NotFoundException
      Try to retrieve a resource from the ontology, based on its lexical form.
      Parameters:
      lex_resource - The URI of a resource in the ontology.
      Returns:
      a RDF model containing all the statements related the the given resource.
      Throws:
      com.hp.hpl.jena.shared.NotFoundException - thrown if the resource doesn't exist in the ontology.
      See Also:
    • getSubmodel

      com.hp.hpl.jena.rdf.model.Model getSubmodel(com.hp.hpl.jena.rdf.model.Resource node) throws com.hp.hpl.jena.shared.NotFoundException
      Returns the set of inferred and asserted statement involving a resource as a Jena Model..
      Parameters:
      resource - A Jena resource.
      Returns:
      a RDF model containing all the statements related the the given resource.
      Throws:
      com.hp.hpl.jena.shared.NotFoundException - thrown if the resource doesn't exist in the ontology.
      See Also:
      • invalid reference
        #getSubmodel(String)
    • createStatement

      com.hp.hpl.jena.rdf.model.Statement createStatement(String statement) throws IllegalStatementException
      This static method acts as a Statement factory. It does some pre-processing to convert a string to a valid statement relative to the given ontology.
      Formatting follows roughly the SPARQL syntax :
      • Literals follows the "value"^^type rule for the general case. Simple or double quotes can be used. Cf examples below.
      • Resources can be either isolated ("individual1"). It will then use the default namespace as defined in the
        invalid reference
        configuration file
        .
      • Or prefixed with the namespace prefix ("rdf:type"),
      • Or complete URIs ("<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>"). In this case, the URI must be enclosed between < and >.

      Literals examples:
      • The boolean true can be represented either as "true"^^xsd:boolean or as true,
      • The integer 123 can be represented either as 123^^xsd:int or as 123. "123"^^xsd:int is also acceptable.
      • The double 1.23 can be represented either as 1.23^^xsd:double or as 1.23. "1.23"^^xsd:double is also acceptable.
      • User-defined dataypes can be represented with "xyz"^^<http://example.org/ns/userDatatype> or "xyz"^^oro:userDatatype.
      The unit test
      invalid reference
      laas.openrobots.ontology.tests.OpenRobotsOntologyTest#testLiterals()
      extensively tests the various literal representation possibilities.
      Parameters:
      statement - a string containing a statement. For example, "oro:individual rdf:type oro:Class1" or "oro:individual <> oro:Class1"
      Returns:
      a new Jena statement
      Throws:
      IllegalStatementException
      See Also:
    • createPartialStatement

      PartialStatement createPartialStatement(String statement) throws IllegalStatementException
      This static method acts as a PartialStatement factory. It does some pre-processing to convert a string to a valid statement relative to the given ontology.
      See createStatement(java.lang.String) for syntax details regarding literals.
      To be valid, a partial statement must have at least one variable, prepended with a "?".
      Parameters:
      statement - a string representing the partial statement. For instance: "?mysterious oro:objProperty2 oro:individual2"
      Returns:
      a new partially defined statement
      Throws:
      IllegalStatementException
      See Also:
    • size

      long size()
      Returns the number of statements in the model.
      Returns:
      the number of statements in the model.
    • getModel

      com.hp.hpl.jena.ontology.OntModel getModel()
      Returns the underlying Jena ontology model.
      Returns:
      the current underlying Jena ontology model.
    • add

      boolean add(Set<com.hp.hpl.jena.rdf.model.Statement> statements, MemoryProfile memProfile, boolean safe) throws IllegalStatementException
      Adds a set of new statements (assertion) to the ontology. If one of the statements already exists, it won't be inserted.
      A memory profile is associated to all the statements: statements associated to
      invalid reference
      MemoryProfile.LONGTERM
      or
      invalid reference
      MemoryProfile.DEFAULT
      are stored and never removed from the ontology while other memory profiles allow the ontology to "forget" about certain facts after a given amount of time.
      Parameters:
      statements - A set of statements to be inserted in the model.
      memProfile - The memory profile associated to this statement.
      safe - If true, the statement is added only if it does not
      Returns:
      True if all the statements have been actually added to the model (actually useful only in conjunction with the safe parameter enabled).
      Throws:
      IllegalStatementException - Currently only thrown if a concept is asserted to be both an instance and a class.
    • add

      @Deprecated boolean add(com.hp.hpl.jena.rdf.model.Statement statement, MemoryProfile memProfile, boolean safe) throws IllegalStatementException
      Deprecated.
      Adds a new statement (assertion) to the ontology.
      Throws:
      IllegalStatementException
      See Also:
    • check

      boolean check(com.hp.hpl.jena.rdf.model.Statement statement)
      Checks if a statement is asserted or can be inferred from the ontology. The check is done in an open world (everything is true except if it's explicitely false). For instance, if only the following statement is asserted:
       bottle hasColor green
       
      check("bottle hasColor orange") would return true. If the two following statements are added to the ontology:
       green owl:isDifferentFrom orange
       hasColor rdf:type owl:functionalProperty
       
      then check("bottle hasColor orange") would return false.
      Parameters:
      statement - the statement to be evaluated
      Returns:
      true if the statement is asserted in or can be inferred from the ontology
    • check

      boolean check(PartialStatement statement)
      Checks if a pattern represented as a partial statement matches at least one asserted of inferred statement.
      For instance:
      • A pattern like [?object rdf:type Bottle] would match all instances of the class Bottle.
      • [anAgent sees ?something] would match all objects seen by instance "anAgent".
      Parameters:
      statement - the partial pattern to be evaluated
      Returns:
      true if the pattern matches at least one asserted or inferred statement of the ontology.
      See Also:
      • invalid reference
        #find(String, Vector)
    • checkConsistency

      boolean checkConsistency()
      Performs a consistency validation against the ontology. Returns false if the check fails.
    • checkConsistency

      boolean checkConsistency(Set<com.hp.hpl.jena.rdf.model.Statement> statements)
      Checks a set of statements (or partial statements) are not inconsistent with the current model. The method temporarily adds the given statements to the model, checks the whole model consistency, remove the statements and return the result of the consistency check (true or false).
      See Also:
    • query

      Set<com.hp.hpl.jena.rdf.model.RDFNode> query(String key, String query) throws InvalidQueryException
      Performs a SPARQL query on the OpenRobots ontology.
      For instance:
              IOntologyServer myOntology = new OpenRobotsOntology();
              ResultSet result =      myOntology.query(
                                                      "PREFIX rdf: invalid input: '<'http://www.w3.org/1999/02/22-rdf-syntax-ns#> \n" +
                                                      "PREFIX owl: invalid input: '<'http://www.w3.org/2002/07/owl#> \n" +
                                                      "SELECT ?instances \n" +
                                                      "WHERE { \n" +
                                                      "?instances rdf:type owl:Thing}\n");
      
       for ( ; result.hasNext() ; )
              {
                      System.out.println(result.nextSolution().toString());
              }
       
      This example would print all the instances existing in the ontology.
      Attention! Unlike other methods which take string representation of statements or resource, namespaces or namespace prefixes CAN NOT be omitted: SELECT ?instance WHERE {?instance eats bananas} won't match the same things as SELECT ?instance WHERE {?instance oro:eats oro:bananas} even if oro is the prefix of the default namespace.
      Parameters:
      query - A well-formed SPARQL query to perform on the ontology. PREFIX statements may be omitted if they are the standard ones (namely, owl, rdf, rdfs) or the LAAS OpenRobots ontology (oro) one.
      query -
      Returns:
      The result of the query as a set of RDFNode (either resources or literals).
      Throws:
      com.hp.hpl.jena.query.QueryParseException - thrown if the argument is not a valid SPARQL query.
      InvalidQueryException
      See Also:
      • invalid reference
        #queryAsXML(String)
    • find

      Set<com.hp.hpl.jena.rdf.model.RDFNode> find(String varName, Set<PartialStatement> statements, Set<String> filters) throws InvalidQueryException
      Tries to identify a resource given a set of partially defined statements (plus optional restrictions) about this resource.
      Parameters:
      varName - The name of the variable to bind, as used in the partial statements.
      statements - A set of partial statements that globaly define a search pattern
      filters - a vector of string containing the various filters to be appended to the search. The syntax is the SPARQL one (as defined here: http://www.w3.org/TR/rdf-sparql-query/#tests).
      Returns:
      a set of resources or literal (RDFNode) that match the statements.
      Throws:
      InvalidQueryException
      See Also:
    • getSuperclassesOf

      Set<com.hp.hpl.jena.ontology.OntClass> getSuperclassesOf(com.hp.hpl.jena.ontology.OntClass type, boolean onlyDirect) throws com.hp.hpl.jena.shared.NotFoundException
      Throws:
      com.hp.hpl.jena.shared.NotFoundException
    • getSubclassesOf

      Set<com.hp.hpl.jena.ontology.OntClass> getSubclassesOf(com.hp.hpl.jena.ontology.OntClass type, boolean onlyDirect) throws com.hp.hpl.jena.shared.NotFoundException
      Throws:
      com.hp.hpl.jena.shared.NotFoundException
    • getInstancesOf

      Set<com.hp.hpl.jena.ontology.OntResource> getInstancesOf(com.hp.hpl.jena.ontology.OntClass type, boolean onlyDirect) throws com.hp.hpl.jena.shared.NotFoundException
      Throws:
      com.hp.hpl.jena.shared.NotFoundException
    • getClassesOf

      Set<com.hp.hpl.jena.ontology.OntClass> getClassesOf(com.hp.hpl.jena.ontology.OntResource individual, boolean onlyDirect) throws com.hp.hpl.jena.shared.NotFoundException
      Throws:
      com.hp.hpl.jena.shared.NotFoundException
    • lookup

      Set<List<String>> lookup(String id)
      Returns the set of all [id, type, label] (with type one of INSTANCE, CLASS, OBJECT_PROPERTY, DATATYPE_PROPERTY, UNDEFINED) of concepts whose labels or id match the given parameter.
      Parameters:
      label - the label (in any language) or id to look for.
      Returns:
      A list made of the id of the concept whose label matches the parameter followed by its type, or an empty set if nothing was found.
      See Also:
    • lookup

      Set<String> lookup(String id, ResourceType type)
      Returns the set of all id of concepts whose labels or ids match the given parameter and of the given type.
      Parameters:
      type - the type of the resource that is looked for.
      label - the label (in any language) or id to look for.
      Returns:
      A set of ids whose label matches the parameter or an empty set.
      See Also:
    • clear

      void clear(PartialStatement partialStmt) throws OntologyServerException
      Remove all statements matching the partial statement. Usage example:
       IOntologyServer myOntology = new OpenRobotsOntology();
       Model results = myOntology.getInfos("ns:individual1");
       
       NodeIterator types = results.listObjectsOfProperty(myOntology.createProperty("rdf:type"));
      
       for ( ; types.hasNext() ; )
       {
              System.out.println(types.nextNode().toString());
       }
       
      Parameters:
      partialStmt - The partial statement representing a "mask" of statements to delete.
      Throws:
      OntologyServerException
    • remove

      @Deprecated void remove(com.hp.hpl.jena.rdf.model.Statement stmt) throws OntologyServerException
      Deprecated.
      Removes a given statement from the ontology. Does nothing if the statement doesn't exist.
      Parameters:
      stmt - The statement to remove from the ontology.
      Throws:
      OntologyServerException
      See Also:
      • invalid reference
        #add(Statement)
    • remove

      void remove(Set<com.hp.hpl.jena.rdf.model.Statement> stmts) throws OntologyServerException
      Removes a set of statements from the ontology. It ignores statements that do not exist.
      Parameters:
      stmts - The statements to remove from the ontology.
      Throws:
      OntologyServerException
      See Also:
      • invalid reference
        #add(Set<Statement>)
    • update

      void update(Set<com.hp.hpl.jena.rdf.model.Statement> stmts) throws IllegalStatementException, InconsistentOntologyException, OntologyServerException
      Update the value of a property. This method is equivalent to a remove(Statement) followed by an add(Set, MemoryProfile, boolean). ATTENTION: this method works only on functional properties (ie, properties that are subclasses of
      owl:FunctionalProperty
      . For non-functional properties (or if the subject or predicate does not exist), this method behaves like
      invalid reference
      #add(Set)
      .
      Parameters:
      stmts - The set of statements to update in the ontology.
      Throws:
      IllegalStatementException
      InconsistentOntologyException
      OntologyServerException
    • save

      void save(String path) throws OntologyServerException
      Saves the in-memory ontology model to a RDF/XML file.
      Parameters:
      path - The path and name of the OWL file to save to (for instance ./ontos/saved.owl)
      Throws:
      OntologyServerException - thrown when the output path is not valid or not accessible.
      See Also:
    • registerEvent

      void registerEvent(IWatcher watcher) throws EventRegistrationException
      Allows to register several events providers (typically, one by underlying middleware) which in turn provide access to watchers. Watchers expose a watch expression which is a SPARQL ASK query. Every time a change is made on the ontology, the ontology backend which implements this interface is expected to execute this query against the model and notify the watchers (through
      invalid reference
      IWatcher#notifySubscriber()
      ) if the result is positive.
      Parameters:
      watcherProviders - A set of event providers.
      Throws:
      EventRegistrationException
      See Also:
    • clearEvents

      void clearEvents()
      Removes all registered event watchers for this model.
    • clearEvent

      void clearEvent(IWatcher watcher) throws OntologyServerException
      Removes one specific event watcher.
      Parameters:
      watcher - the watcher to remove
      Throws:
      OntologyServerException
    • getSupportedEvents

      Set<IWatcher.EventType> getSupportedEvents()
      Return the list of event types implemented (hence usable) by this backend.
      Returns:
      The list of event type supported by the backend
    • step

      void step()
      'Step' the model. At each server main loop iteration, the 'step' method is called for each model. The model can do here its own internal homeworks.
    • close

      void close()
      Closes the model