// Copyright (c) 2000 Just Objects B.V. <just@justobjects.nl>// Distributable under LGPL license. See terms of license at gnu.org.package nl.justobjects.pushlet.core;import nl.justobjects.pushlet.util.Rand;import nl.justobjects.pushlet.util.PushletException;/** * Represents single subject subscription * * @author Just van den Broecke - Just Objects &copy; * @version $Id: Subscription.java,v 1.5 2007/11/23 14:33:07 justb Exp $ */public class Subscription implements ConfigDefs {	public static final int ID_SIZE = 5;	public static final String SUBJECT_SEPARATOR = ",";	private String id = Rand.randomName(ID_SIZE);	private String subject;	private String[] subjects;	/**	 * Optional label, a user supplied token.	 */	private String label;	/**	 * Protected constructor as we create through factory method.	 */	protected Subscription() {	}	/**	 * Create instance through factory method.	 *	 * @param aSubject the subject (topic).	 * @return a Subscription object (or derived)	 * @throws nl.justobjects.pushlet.util.PushletException	 *          exception, usually misconfiguration	 */	public static Subscription create(String aSubject) throws PushletException {		return create(aSubject, null);	}	/**	 * Create instance through factory method.	 *	 * @param aSubject the subject (topic).	 * @param aLabel   the subject label (optional).	 * @return a Subscription object (or derived)	 * @throws nl.justobjects.pushlet.util.PushletException	 *          exception, usually misconfiguration	 */	public static Subscription create(String aSubject, String aLabel) throws PushletException {		if (aSubject == null || aSubject.length() == 0) {			throw new IllegalArgumentException("Null or emtpy subject");		}		Subscription subscription;		try {			subscription = (Subscription) Config.getClass(SUBSCRIPTION_CLASS, "nl.justobjects.pushlet.core.Subscription").newInstance();		} catch (Throwable t) {			throw new PushletException("Cannot instantiate Subscriber from config", t);		}		// Init		subscription.subject = aSubject;		// We may subscribe to multiple subjects by separating		// them with SUBJECT_SEPARATOR, e.g. "/stocks/aex,/system/memory,..").		subscription.subjects = aSubject.split(SUBJECT_SEPARATOR);		subscription.label = aLabel;		return subscription;	}	public String getId() {		return id;	}	public String getLabel() {		return label;	}	public String getSubject() {		return subject;	}	/**	 * Determine if Event matches subscription.	 */	public boolean match(Event event) {		String eventSubject = event.getSubject();		// Silly case but check anyway		if (eventSubject == null || eventSubject.length() == 0) {			return false;		}		// Test if one of the subjects matches		for (int i = 0; i < subjects.length; i++) {			if (eventSubject.startsWith(subjects[i])) {				return true;			}		}		// No match		return false;	}}/*  * $Log: Subscription.java,v $  * Revision 1.5  2007/11/23 14:33:07  justb  * core classes now configurable through factory  *  * Revision 1.4  2006/05/06 00:10:11  justb  * various chgs but not too serious...  *  * Revision 1.3  2005/02/16 15:23:10  justb  * multiple subject (, separated) support  *  * Revision 1.2  2005/01/18 16:47:10  justb  * protocol changes for v2 and publishing from pushlet client  *  * Revision 1.1  2004/09/26 21:39:43  justb  * allow multiple subscriptions and out-of-band requests  *  *  */