modulespecid.java

JXTA&#8482 is a set of open, generalized peer-to-peer (P2P) protocols that allow any networked devi

/*
 * Copyright (c) 2001-2007 Sun Microsystems, Inc.  All rights reserved.
 *  
 *  The Sun Project JXTA(TM) Software License
 *  
 *  Redistribution and use in source and binary forms, with or without 
 *  modification, are permitted provided that the following conditions are met:
 *  
 *  1. Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *  
 *  2. Redistributions in binary form must reproduce the above copyright notice, 
 *     this list of conditions and the following disclaimer in the documentation 
 *     and/or other materials provided with the distribution.
 *  
 *  3. The end-user documentation included with the redistribution, if any, must 
 *     include the following acknowledgment: "This product includes software 
 *     developed by Sun Microsystems, Inc. for JXTA(TM) technology." 
 *     Alternately, this acknowledgment may appear in the software itself, if 
 *     and wherever such third-party acknowledgments normally appear.
 *  
 *  4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must 
 *     not be used to endorse or promote products derived from this software 
 *     without prior written permission. For written permission, please contact 
 *     Project JXTA at http://www.jxta.org.
 *  
 *  5. Products derived from this software may not be called "JXTA", nor may 
 *     "JXTA" appear in their name, without prior written permission of Sun.
 *  
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
 *  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 
 *  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SUN 
 *  MICROSYSTEMS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 
 *  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 
 *  OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 
 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 
 *  EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *  
 *  JXTA is a registered trademark of Sun Microsystems, Inc. in the United 
 *  States and other countries.
 *  
 *  Please see the license information page at :
 *  <http://www.jxta.org/project/www/license.html> for instructions on use of 
 *  the license in source files.
 *  
 *  ====================================================================
 *  
 *  This software consists of voluntary contributions made by many individuals 
 *  on behalf of Project JXTA. For more information on Project JXTA, please see 
 *  http://www.jxta.org.
 *  
 *  This license is based on the BSD license adopted by the Apache Foundation. 
 */

package net.jxta.platform;


import java.net.URI;
import net.jxta.id.ID;


/**
 * A ModuleSpecID uniquely identifies a particular network behaviour
 * (wire protocol and choregraphy) that may be embodied by a Jxta Module.
 * There may be any number of implementations of a given SpecID. All
 * such implementations are assumed to be network compatible.
 *
 * <p>
 * The Specification that corresponds to a given ModuleSpecID may be published
 * in a ModuleSpecAdvertisement. This advertisement is uniquely identified by
 * the ModuleSpecID that it describes.
 *
 * <p>
 * The various implementations of a given SpecID may be published in
 * ModuleImplAdvertisements. These advertisements are identified by the
 * ModuleSpecID that they implement and a compatibility statement.
 * ModuleImplAdvertisements baring the same SpecID and compatibility statement
 * are theorethicaly interchangeable. However they may be subsequently discriminated
 * by a Description element.
 *
 * <p>
 * A ModuleSpecID embeds a ModuleClassID which uniquely identifies a base Module
 * class. A base module class defines a local behaviour and one API per compatible
 * JXTA implementation.
 * 
 * <p>
 * A ModuleSpecID therefore uniquely identifies an abstract module, of which an
 * implementation compatible with the local JXTA implementation may be located and
 * instantiated.
 *
 * <p>
 * In the standard PeerGroup implementation of the java reference implementation
 * the various services are specified as a list of ModuleSpecID, for each of which
 * the group locates and loads an implementation as part of the group's
 * initialization.
 *
 * @see net.jxta.peergroup.PeerGroup
 * @see net.jxta.platform.Module
 * @see net.jxta.platform.ModuleClassID
 * @see net.jxta.protocol.ModuleSpecAdvertisement
 * @see net.jxta.protocol.ModuleImplAdvertisement
 * @see net.jxta.id.ID
 * @see net.jxta.document.Advertisement
 *
 */

public abstract class ModuleSpecID extends ID {

    /**
     * Creates an ID by parsing the given URI.
     *
     * <p>This convenience factory method works as if by invoking the
     * {@link net.jxta.id.IDFactory#fromURI(URI)} method; any 
     * {@link java.net.URISyntaxException} thrown is caught and wrapped in a 
     * new {@link IllegalArgumentException} object, which is then thrown.  
     *
     * <p> This method is provided for use in situations where it is known that
     * the given string is a legal ID, for example for ID constants declared
     * within in a program, and so it would be considered a programming error
     * for the URI not to parse as such.  The {@link net.jxta.id.IDFactory}, 
     * which throws {@link java.net.URISyntaxException} directly, should be used 
     * situations where a ID is being constructed from user input or from some 
     * other source that may be prone to errors. 
     *
     * @param  fromURI   The URI to be parsed into an ID
     * @return The new ID
     *
     * @throws  NullPointerException If {@code fromURI} is {@code null}.
     * @throws  IllegalArgumentException If the given URI is not a valid ID.
     */
    public static ModuleSpecID create(URI fromURI) {
        return (ModuleSpecID) ID.create(fromURI);
    }
    
    /**
     *  {@inheritDoc}
     */
    public ModuleSpecID intern() {
        return (ModuleSpecID) super.intern();
    }
    
    /**
     * Returns true if this ModuleSpecID is of the same base class than the
     * given class.
     * Note: This method is NOT named "isOfClass" because a ModuleClassID
     * may have two portions; one that denotes a class proper,
     * and an optional second one that denotes a "Role". For convenience, we refer
     * the class stripped of its role portion as "the base class" although this is not
     * a totally accurate term.
     * A ModuleSpecID, is of a base class but is not related to any kind
     * of role. So using "isOfClass" could be misleading.
     * Base classes are represented by a class with the role ID set to zero, which
     * happens to be a valid class. This routine may be used for comparison with
     * such a class, of course.
     *
     * @param id Module class id to compare with
     * @return boolean true if equals
     *
     */
    
    public abstract boolean isOfSameBaseClass(ModuleClassID id);

    /**
     * Returns true if this ModuleSpecID is of the same base class than the
     * the given ModuleSpecID.
     *
     * @param id Module spec id to compare with
     * @return boolean true if equals
     *
     */
    
    public abstract boolean isOfSameBaseClass(ModuleSpecID id);

    /**
     * Return a ModuleClassID of the same base class but with the role portion
     * set to zero. aka "the base class".
     *
     * @return ModuleClassID the base class.
     *
     */

    public abstract ModuleClassID getBaseClass();
}