damlhierarchy.java

jena2.5.4推理机系统的一种最基本实现 HP实验室出品

/*****************************************************************************
 * Source code information
 * -----------------------
 * Original author    Ian Dickinson, HP Labs Bristol
 * Author email       [e-mail]
 * Package            Jena
 * Created            7 Sept 2001
 * Filename           $RCSfile: DAMLHierarchy.java,v $
 * Revision           $Revision: 1.9 $
 * Release status     Preview-release $State: Exp $
 *
 * Last modified on   $Date: 2007/01/08 14:40:30 $
 *               by   $Author: ian_dickinson $
 *
 * (c) Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007 Hewlett-Packard Development Company, LP
 * (see footer for full conditions)
 *****************************************************************************/

// Package
///////////////
package com.hp.hpl.jena.ontology.daml.impl;


// Imports
///////////////

import com.hp.hpl.jena.vocabulary.*;
import com.hp.hpl.jena.rdf.model.*;

import java.util.*;



/**
 * Represents knowledge about the class and property hierarchies in the DAML spec,
 * so that these can be available without forcing the user to import the DAML specification
 * into their model each time. Uses Singleton pattern.
 *
 * @author Ian Dickinson, HP Labs (<a href="mailto:[e-mail]">email</a>)
 * @version CVS info: $Id: DAMLHierarchy.java,v 1.9 2007/01/08 14:40:30 ian_dickinson Exp $
 * @deprecated The DAML API is scheduled to be removed from Jena 2.6 onwards. Please use the DAML profile in the main ontology API
 */
public class DAMLHierarchy
{
    // Constants
    //////////////////////////////////


    // Static variables
    //////////////////////////////////

    /** The singleton instance */
    private static DAMLHierarchy s_instance = new DAMLHierarchy();


    // Instance variables
    //////////////////////////////////

    /**
     * Map of DAML and RDF standard classes that are super-classes of other DAML standard classes.
     * Assumes each class has at most one super-class.
     */
    public Resource[][] DAML_STANDARD_CLASS_HIERARCHY = new Resource[][] {
        // sub-class                           super-class
        {DAML_OIL.Class,                       RDFS.Class},
        {DAML_OIL.Datatype,                    RDFS.Class},
        {DAML_OIL.Restriction,                 DAML_OIL.Class},
        {DAML_OIL.ObjectProperty,              RDF.Property},
        {DAML_OIL.DatatypeProperty,            RDF.Property},
        {DAML_OIL.TransitiveProperty,          DAML_OIL.ObjectProperty},
        {DAML_OIL.UnambiguousProperty,         DAML_OIL.ObjectProperty},
        {DAML_OIL.UniqueProperty,              RDF.Property},
        {DAML_OIL.List,                        RDF.Seq},
    };


    /**
     * Known equivalences between DAML and RDFS values
     */
    public Resource[][] DAML_STANDARD_EQUIVALENCES = new Resource[][] {
        {DAML_OIL.subClassOf,                   RDFS.subClassOf},
        {DAML_OIL.Literal,                      RDFS.Literal},
        {DAML_OIL.Property,                     RDF.Property},
        {DAML_OIL.type,                         RDF.type},
        {DAML_OIL.value,                        RDF.value},
        {DAML_OIL.subPropertyOf,                RDFS.subPropertyOf},
        {DAML_OIL.domain,                       RDFS.domain},
        {DAML_OIL.range,                        RDFS.range},
        {DAML_OIL.label,                        RDFS.label},
        {DAML_OIL.comment,                      RDFS.comment},
        {DAML_OIL.seeAlso,                      RDFS.seeAlso},
        {DAML_OIL.isDefinedBy,                  RDFS.isDefinedBy},
    };


    /** A list of well-known properties that are known a priori to be transitive */
    public Property[] TRANSITIVE_PROPERTIES = new Property[] {
        DAML_OIL.subClassOf,
        DAML_OIL.subPropertyOf,
        DAML_OIL.sameClassAs,
        DAML_OIL.sameIndividualAs,
        DAML_OIL.samePropertyAs,
        DAML_OIL.equivalentTo,

        RDFS.subClassOf,
        RDFS.subPropertyOf
    };

    /** Super-class hierarchy hashmap */
    protected Map m_classHierarchyMap = new HashMap();

    /** Flag to show initialisation of static structures has taken place */
    protected boolean m_initialised = false;

    /** Equivalance map */
    protected Map m_equivalenceMap = new HashMap();

    /** Table of transitive properties */
    protected Map m_transitiveProperties = new HashMap();



    // Constructors
    //////////////////////////////////

    /**
     * Constructor is private to enforce singleton design pattern.
     */
    private DAMLHierarchy() {
    }


    // External signature methods
    //////////////////////////////////

    /**
     * Answer the singleton instance.
     *
     * @return the unique DAMLHierarchy
     */
    public static DAMLHierarchy getInstance() {
        return s_instance;
    }


    /**
     * Answer true if the first URI represents a class in the standard DAML ontology
     * that is a super-class of the class denoted by the second URI.  This is used to
     * provide background knowledge from the standard DAML ontology without having
     * to explicitly import it each time.
     *
     * @param uri0 A class URI
     * @param uri1 A class URI
     * @return true if the class denoted by uri0 is a sub-class of the class denoted by uri1
     */
    public boolean isDAMLSubClassOf( String uri0, String uri1 ) {
        // only works for named classes, so if the uri's are null or empty (indicating
        // anonymous resources) we skip
        if ((uri0 == null)  ||  (uri1 == null)  ||
            (uri0.length() == 0)  ||  (uri1.length() == 0)) {
            return false;
        }

        // ensure that the structure has been initialised
        initialiseMaps();

        // first, is uri0 directly a sub-class of uri1?
        String superClass = (String) m_classHierarchyMap.get( uri0 );

        if (uri1.equals( superClass )) {
            // found a match
            return true;
        }
        else {
            // NOTE: assumes there is at most one super-class for each class, which is
            // true in current releases of DAML but may not remain true forever.
            return superClass == null ? false : isDAMLSubClassOf( superClass, uri1 );
        }
    }


    /**
     * Answer true if the given property is well-known to be transitive. That is,
     * it is transitive even though it is not marked as being in the class of
     * transitive properties defined by the TransitiveProperty class.  Note: this
     * test does not check for <code>rdf:type TransitiveProperty</code>, it <i>only</i>
     * tests the table of well-known transitive properties.
     *
     * @param res A resource
     * @return True if the resource is a Property, and it is a member of the set
     *         of well-known transitive properties.
     */
    public boolean isTransitiveProperty( Resource res ) {
        return (res instanceof Property  &&  m_transitiveProperties.containsKey( res ));
    }


    /**
     * Answer an iteration of those values that are equivalent to the given resource.
     *
     * @param res A resource, that may have known equivalent values
     * @return an iteration over the resource's equivalent values, which may be empty
     *         but will not be null.
     */
    public Iterator getEquivalentValues( Resource res ) {
        // ensure that the cache structure has been initialised
        initialiseMaps();

        LinkedList equivs = (LinkedList) m_equivalenceMap.get( res );
        return (equivs == null) ? new LinkedList().iterator() : equivs.iterator();
    }



    // Internal implementation methods
    //////////////////////////////////

    /**
     * Initialise the static structures we need to process class hierarchy queries.
     * Note that we don't do this as a static to avoid race conditions with setting
     * up the vocabularies.
     */
    private void initialiseMaps() {
        if (!m_initialised) {
            // initialise the class hierachy map for known standard DAML classes
            for (int i = 0;  i < DAML_STANDARD_CLASS_HIERARCHY.length;  i++) {
                String subClass   = DAML_STANDARD_CLASS_HIERARCHY[i][0].getURI();
                String superClass = DAML_STANDARD_CLASS_HIERARCHY[i][1].getURI();

                m_classHierarchyMap.put( subClass, superClass );
            }

            // initialise the equivalence map - note symmetric relation, so we have to do both directions
            for (int i = 0;  i < DAML_STANDARD_EQUIVALENCES.length;  i++) {
                // first do the forwards direction
                LinkedList l = (LinkedList) m_equivalenceMap.get( DAML_STANDARD_EQUIVALENCES[i][0] );

                if (l == null) {
                    // if no list of equivs yet, create one
                    l = new LinkedList();
                    m_equivalenceMap.put( DAML_STANDARD_EQUIVALENCES[i][0], l );
                }

                l.add( DAML_STANDARD_EQUIVALENCES[i][1] );

                // now do the reverse direction
                l = (LinkedList) m_equivalenceMap.get( DAML_STANDARD_EQUIVALENCES[i][1] );

                if (l == null) {
                    // if no list of equivs yet, create one
                    l = new LinkedList();
                    m_equivalenceMap.put( DAML_STANDARD_EQUIVALENCES[i][1], l );
                }

                l.add( DAML_STANDARD_EQUIVALENCES[i][0] );
            }

            // initialise the transitive properties map, for efficiency
            for (int i = 0;  i < TRANSITIVE_PROPERTIES.length;  i++) {
                m_transitiveProperties.put( TRANSITIVE_PROPERTIES[i], Boolean.TRUE );
            }

            m_initialised = true;
        }
    }



    //==============================================================================
    // Inner class definitions
    //==============================================================================


}


/*
    (c) Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007 Hewlett-Packard Development Company, LP
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
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       notice, this list of conditions and the following disclaimer.

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       notice, this list of conditions and the following disclaimer in the
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    3. The name of the author may not be used to endorse or promote products
       derived from this software without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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