/* * Copyright (c) 2001 Sun Microsystems, Inc.  All rights * reserved. * * 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 the *       Sun Microsystems, Inc. for Project JXTA." *    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 THE APACHE SOFTWARE FOUNDATION 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. * *==================================================================== * * 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. * * $Id: LiteXMLMetadata.java,v 1.5 2006/02/07 20:43:48 bondolo Exp $ * */package net.jxta.share.metadata;import net.jxta.document.*;import org.apache.log4j.*;import java.util.*;/**<code>LiteXMLMetadata</code> is a class for storing metadata whose payload * can be represented as in the LiteXML used by <code>StructuredDocument</code> * and <code>Element</code> objects. *@see net.jxta.document.StructuredDocument *@see net.jxta.document.Element *@author $Author: bondolo $ *@version $Revision: 1.5 $ */public abstract class LiteXMLMetadata extends ContentMetadata {    private final static transient Logger LOG = Logger.getLogger(LiteXMLMetadata.class.getName());        /**The content type of LiteXML-encoded metadata     */    public static final String LITEXML_CONTENT_TYPE = "text/litexml";    /**<code>content_type</code> is automatically initialized to     * <code>LITEXML_CONTENT_TYPE</code>     */    protected final String content_type = LITEXML_CONTENT_TYPE;    /**Initialize the <code>name</code> and <code>location</code> fields from a     * <code>&lt;metadata></code> block.     *@param metadata the <code>&lt;metadata></code> block     *@exception IllegalArgumentException - if <code>metadata</code> is null or     * <code>metadata.getKey().equals(EN_METADATA)</code> returns false.     */    protected void init(Element metadata) throws IllegalArgumentException {	if(metadata == null)	    throw new IllegalArgumentException("null argument");	if(!metadata.getKey().equals(EN_METADATA))	    throw new IllegalArgumentException("invalid key name: "					       +metadata.getKey());	Element schemeEl;	Enumeration children = metadata.getChildren(EN_SCHEME);	if(children.hasMoreElements()) {	    schemeEl = (Element)children.nextElement();	    String sChildKey;	    Object temp;	    Element sChildEl;	    Enumeration sChildren = schemeEl.getChildren();	    while(sChildren.hasMoreElements()) {		sChildEl = (Element)sChildren.nextElement();		sChildKey = sChildEl.getKey().toString();		temp = sChildEl.getValue();		//if no value is set for an element, assume that the value is		// meant to be an empty string		if(temp == null)		    temp = "";		if(sChildKey.equals(EN_NAME)) {		    if((name != null) && (LOG.isEnabledFor(Level.WARN)))			LOG.warn("multiple <name> elements");		    name = temp.toString();		}else if(sChildKey.equals(EN_LOCATION)) {		    if((location != null) && (LOG.isEnabledFor(Level.WARN)))			LOG.warn("multiple <location> elements");		    location = temp.toString();		}	    }	    	    //write to the log if either name or debug is empty or null	    if((name == null) && (LOG.isEnabledFor(Level.DEBUG)))		LOG.debug("scheme has undefined name");	} else if(LOG.isEnabledFor(Level.DEBUG)){	    LOG.debug("<scheme> element not found");	}		if(children.hasMoreElements() && LOG.isEnabledFor(Level.WARN))	    LOG.warn("multiple <scheme> elements");    }    /**Get the string representation of the metadata payload, or null if the     * metadata has no string representation.     *@return null because LiteXMLMetadata does not represent its metadata as     * a string.     */    public String getValue() {	return null;    }    /**Return all of the metadata elements as children of a specific     * StructuredDocument.     */    public abstract Element[] getMetadataElements(StructuredDocument root);        /**Insert the child elements of this metadata element into a specified     * element of a StructuredDocument.     *      * @param root the StructuredDocument which <code>child</code> is a part of     * @param child the Element object into which to insert the metadata     */    protected void appendElements(StructuredDocument root, Element child) {    	Element schemeEl = root.createElement(EN_SCHEME);	child.appendChild(schemeEl);		if(name != null)	    schemeEl.appendChild(root.createElement(EN_NAME, name));		if(location != null)	    schemeEl.appendChild(root.createElement(EN_LOCATION, location));		//content_type can never be null because it is final and initialized to	//a non-null value	schemeEl.appendChild(root.createElement(EN_CONTENT_TYPE,						    content_type));		Element[] metadataElements = getMetadataElements(root);	for(int i = 0; i < metadataElements.length; i++)	    child.appendChild(metadataElements[i]);    }            /**Generates a StructuredDocument representation of this metadata element     *      * @param mmt the mime type of the StructuredDocument to be returned     * @return a StructuredDocument of type <code>EN_METADATA</code> with     * containing all of the metadata information stored in this object.     */    public StructuredDocument getStructuredDocument(MimeMediaType mmt) {    	StructuredDocument doc	    = StructuredDocumentFactory.newStructuredDocument(mmt,EN_METADATA);    	appendElements(doc, doc);    	return doc;    }}