/* -*- Mode: Java; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- * * The contents of this file are subject to the Netscape Public License * Version 1.0 (the "NPL"); you may not use this file except in * compliance with the NPL. You may obtain a copy of the NPL at * http://www.mozilla.org/NPL/ * * Software distributed under the NPL is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL * for the specific language governing rights and limitations under the * NPL. * * The Initial Developer of this code under the NPL is Netscape * Communications Corporation. Portions created by Netscape are * Copyright (C) 1998 Netscape Communications Corporation. All Rights * Reserved. */ package netscape.rdf; import java.util.Enumeration; /** * Interface to an RDF database. *

* Use RDFFactory to get an instance of an RDF database. * @see netscape.rdf.RDFFactory */ public interface IRDF { /** * Relate nodes src and target in the RDF database with arcLabel * This creates a positive relationship in the database: target is * related to src by the relationship named arcLabel. * * @param src * the src node in the RDF graph * @param arcLabel * the label of the arc connecting target and src * @param target * the target node in the RDF graph * @return null to indicate success or a resource describing * the failure */ public Resource assert(Resource src, Resource arcLabel, Integer target); public Resource assert(Resource src, Resource arcLabel, String target); public Resource assert(Resource src, Resource arcLabel, Resource target); /** * Relate nodes src and target in the RDF database with arcLabel * This creates a negative relationship in the database: target is not * related to src by the relationship named arcLabel. * * @param src * the src node in the RDF graph * @param arcLabel * the label of the arc connecting target and src * @param target * the target node in the RDF graph * @return null to indicate success or a resource describing * the failure */ public Resource assertFalse(Resource src, Resource arcLabel, Integer target); public Resource assertFalse(Resource src, Resource arcLabel, String target); public Resource assertFalse(Resource src, Resource arcLabel, Resource target); /** * Make it so that as seen from the local layer, src->arcLabel->targetis * not true. If src->arcLabel->target is true in a modifiable layer, modify it. * Otherwise add something in the local layer so that this gets blocked. * * @param src * the src node in the graph * @param arcLabel * the arc class to remove * @param target * the target node in the graph * @return null to indicate success or a resource describing * the failure */ public Resource unassert(Resource src, Resource arcLabel, Integer target); public Resource unassert(Resource src, Resource arcLabel, String target); public Resource unassert(Resource src, Resource arcLabel, Resource target); /** * Returns true if src->arcLabel->target has the truth value isTrue * * @param src * the src node in the graph * @param arcLabel * the label of arc to query * @param target * the target node in the graph * @param isTrue * the truth value associated with arcLabel * @return true if assertion exists with isTrue truth value, false otherwise. */ public boolean hasAssertion(Resource src, Resource arcLabel, Integer target, boolean isTrue); public boolean hasAssertion(Resource src, Resource arcLabel, String target, boolean isTrue); public boolean hasAssertion(Resource src, Resource arcLabel, Resource target, boolean isTrue); /** * Returns an enumeration Resources which are the targets of src * using arc arcLabel which have the truth value isTrue. * * @param src * the src node in the graph * @param arcLabel * the label of arc to query * @param isTrue * the truth value associated with arcLabel * @return an enumeration of Resources, or NULL if none exist. */ public Enumeration getTargets(Resource src, Resource arcLabel, boolean isTrue); /** * Returns the first target of src using * arc arcLabel which has the truth value isTrue. * * @param src * the src node in the graph * @param arcLabel * the label of arc to query * @param isTrue * the truth value associated with arcLabel * @return an Object of type Resource, Integer or String or null */ public Object getTarget(Resource src, Resource arcLabel, boolean isTrue); /** * Returns an enumeration of Resources which are the sources * of target using arc arcLabel which have the truth value isTrue. * * @param arcLabel * the label of arc to query * @param target * the target node in the graph * @param isTrue * the truth value associated with arcLabel * @return an enumeration of Resources, or null */ public Enumeration getSources(Resource arcLabel, Integer target, boolean isTrue); public Enumeration getSources(Resource arcLabel, String target, boolean isTrue); public Enumeration getSources(Resource arcLabel, Resource target, boolean isTrue); /** * Returns the Resource which is the first source of target using * arc arcLabel which has the truth value isTrue. * * @param arcLabel * the label of arc to query * @param target * the target node in the graph * @param isTrue * the truth value associated with arcLabel * * @return The requested Resource, or null */ public Resource getSource(Resource arcLabel, Integer target, boolean isTrue); public Resource getSource(Resource arcLabel, String target, boolean isTrue); public Resource getSource(Resource arcLabel, Resource target, boolean isTrue); /** * Clients call this method to register an object to be notified of events * happening within the RDF database. The Vector events must contain subclasses * of RDFEvent, if it does not an instance of RDFNotifiableException is thrown * * @param obs * the object to call when an event specified in eventmask occurs within the RDF database * @param events * a vector of the RDFEvents of interest * * @return true if obs was successfully installed as a notifiable * @see netscape.rdf.RDFEvent */ public boolean addNotifiable(IRDFNotifiable obs, RDFEvent event); /** * Clients call this method to unregister an object from receiving notifications. * The Vector events must contain subclasses of RDFEvent, if it does not * an instance of RDFNotifiableException is thrown * * @param obs * the object to remove from the list of observers. * @param events * the RDFEvents to stop listening to * @see netscape.rdf.RDFEvent */ public void deleteNotifiable(IRDFNotifiable obs, RDFEvent event); /** * Returns the URL(s) used to create this RDF database. * * @return A vector of URLs. * @see netscape.rdf.RDFFactory */ public String[] getRDFStores(); }