moduleimpladvertisement.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 
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 *  
 *  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.protocol;


import net.jxta.document.Element;
import net.jxta.document.ExtendableAdvertisement;
import net.jxta.document.MimeMediaType;
import net.jxta.document.StructuredDocument;
import net.jxta.document.StructuredDocumentFactory;
import net.jxta.document.StructuredDocumentUtils;
import net.jxta.id.ID;
import net.jxta.platform.ModuleSpecID;


/**
 * A ModuleImplAdvertisement describes one of any number of published
 * implementations for a given specification.
 * <p/>
 * Module specifications are referenced by their ModuleSpecID. Given a
 * ModuleSpecID, a ModuleImplAdvertisement may be searched by means of JXTA
 * Discovery, filtered according to the compatibility statement it contains,
 * and if compatible, loaded and initialized. The {@code loadModule()} method of
 * PeerGroup performs this task automatically, given a ModuleSpecID.
 * <p/>
 * One significant example of Modules referenced and loaded in that manner are
 * the services and protocols that constitute a StdPeerGroup in the Java
 * reference implementation.
 *
 * @see net.jxta.id.ID
 * @see net.jxta.platform.ModuleSpecID
 * @see net.jxta.document.Advertisement
 * @see net.jxta.document.StructuredDocument
 * @see net.jxta.document.Element
 * @see net.jxta.protocol.ModuleSpecAdvertisement
 * @see net.jxta.peergroup.PeerGroup
 */
public abstract class ModuleImplAdvertisement extends ExtendableAdvertisement implements Cloneable {
    
    private ModuleSpecID msid = null;
    private StructuredDocument description = null;
    private StructuredDocument compat = null;
    private String code = null;
    private String uri = null;
    private String provider = null;
    private StructuredDocument param = null;
    
    /**
     *  Returns the identifying type of this Advertisement.
     *
     * @return String the type of advertisement
     */
    public static String getAdvertisementType() {
        return "jxta:MIA";
    }
    
    /**
     * {@inheritDoc}
     */
    @Override
    public final String getBaseAdvType() {
        return getAdvertisementType();
    }
    
    /**
     * Clone this ModuleImplAdvertisement
     */
    @Override
    public ModuleImplAdvertisement clone() {
        
        try {
            ModuleImplAdvertisement clone = (ModuleImplAdvertisement) super.clone();
            
            clone.setModuleSpecID(getModuleSpecID());
            clone.setDesc(getDescPriv());
            clone.setCompat(getCompatPriv());
            clone.setCode(getCode());
            clone.setUri(getUri());
            clone.setProvider(getProvider());
            clone.setParam(getParamPriv());
            
            return clone;
        } catch (CloneNotSupportedException impossible) {
            throw new Error("Object.clone() threw CloneNotSupportedException", impossible);
        }
    }
    
    /**
     * Returns the unique ID of that advertisement for indexing purposes.
     * In that case we do not have any particular one to offer. Let the indexer
     * hash the document.
     *
     * @return ID the unique id
     */
    @Override
    public ID getID() {
        return null;
    }
    
    /**
     * Returns the id of the spec that this implements.
     * @return ID the spec id
     *
     */
    public ModuleSpecID getModuleSpecID() {
        return msid;
    }
    
    /**
     * Sets the id of the spec that is implemented
     * 
     * @param msid The id of the spec
     */
    public void setModuleSpecID(ModuleSpecID msid) {
        this.msid = msid;
    }
    
    /**
     * returns the description
     *
     * @return String the description
     */
    public String getDescription() {
        if (null != description) {
            return (String) description.getValue();
        } else {
            return null;
        }
    }
    
    /**
     * sets the description
     *
     * @param description the description
     */
    public void setDescription(String description) {
        
        if (null != description) {
            StructuredDocument newdoc = StructuredDocumentFactory.newStructuredDocument(MimeMediaType.XMLUTF8, "Desc", description);
            
            setDesc(newdoc);
        } else {
            this.description = null;
        }
    }
    
    /**
     * returns the description
     *
     * @return the description
     */
    public StructuredDocument getDesc() {
        if (null != description) {
            StructuredDocument newDoc = StructuredDocumentUtils.copyAsDocument(description);
            
            return newDoc;
        } else {
            return null;
        }
    }
    
    /**
     * Privileged version of {@link #getDesc()} that does not clone the elements.
     *
     * @return the description
     */
    public StructuredDocument getDescPriv() {
        return description;
    }
    
    /**
     * sets the description
     *
     * @param desc the description
     */
    public void setDesc(Element desc) {
        
        if (null != desc) {
            this.description = StructuredDocumentUtils.copyAsDocument(desc);
        } else {
            this.description = null;
        }
    }
 
    /**
     * Returns the opaque compatibility statement for this advertisement. Each
     * JXTA implementation has the ability to recognize and evaluate it's own
     * compatibility statements (even though it may not be able to evaluate the
     * compatibility statements of other implementations).  
     *
     * @return The compatibility statement as a StructuredDocument of 
     * unspecified content.
     */
    public StructuredDocument getCompat() {
        return (compat == null ? null : StructuredDocumentUtils.copyAsDocument(compat));
    }
    
    /**
     * Privileged version of {@link #getCompat()} that does not clone the elements.
     *
     * @return The compatibility statement as a StructuredDocument of 
     * unspecified content.
     */
    protected StructuredDocument getCompatPriv() {
        return compat;
    }
    
    /**
     * Sets the module impl. compatibility statement.
     *
     * @param compat Element of an unspecified content.
     */
    public void setCompat(Element compat) {
        this.compat = (compat == null ? null : StructuredDocumentUtils.copyAsDocument(compat));
    }
    
    /**
     * returns the code; a reference to or representation of the executable code
     * advertised by this advertisement.
     * <p/>
     * The appropriate interpretation of the code value is dependant upon the 
     * compatibility statement. Any compatible consumer of this advertisement   
     * will be able to correctly interpret code value. The standard group 
     * implementations of the JXSE reference implementation expect it to be a 
     * reference to a jar file.
     *
     * @return A reference to the executable code described by this 
     * advertisement.
     */
    public String getCode() {
        return code;
    }
    
    /**
     * Sets the reference for the executable code described by this 
     * advertisement.
     *
     * @param code A reference to the executable code described by this 
     * advertisement.
     */
    public void setCode(String code) {
        this.code = code;
    }
    
    /**
     * returns the uri; that is a reference to or representation of a package 
     * from which the executable code referenced by the getCode method may be 
     * loaded.
     * <p/>
     * The appropriate interpretation of the URI value is dependant upon the 
     * compatibility statement. Any compatible consumer of this advertisement   
     * will be able to correctly interpret the URI value. The standard group 
     * implementations of the JXSE reference implementation expect it to be a 
     * reference to a jar file.
     *
     * @return Location URI for the code described by this advertisement.
     */
    public String getUri() {
        return uri;
    }
    
    /**
     * Sets the uri
     *
     * @param uri Location URI for the code described by this advertisement.
     */
    public void setUri(String uri) {
        this.uri = uri;
    }
    
    /**
     * returns the provider
     *
     * @return String the provider
     */
    public String getProvider() {
        return provider;
    }
    
    /**
     * sets the provider
     *
     * @param provider the provider
     */
    public void setProvider(String provider) {
        this.provider = provider;
    }
    
    /**
     * returns the param element.
     *
     * The interpretation of the param element is entirely up to the code
     * that this advertises. One valid use of it is to enable the code to
     * be configured so that multiple specs or multiple implementations of
     * one spec may use the same code.
     *
     * @return A standalone structured document of unspecified content.
     */
    public StructuredDocument getParam() {
        return (param == null ? null : StructuredDocumentUtils.copyAsDocument(param));
    }
    
    /**
     * Privileged version of {@link #getParam()} that does not clone the elements.
     *
     * @return A standalone structured document of unspecified content.
     */
    protected StructuredDocument getParamPriv() {
        return param;
    }
    
    /**
     * Sets the module param
     *
     * @param param Element of an unspecified content.
     */
    public void setParam(Element param) {
        this.param = (param == null ? null : StructuredDocumentUtils.copyAsDocument(param));
    }
}