session.java

Java下Comet的实现框架Pushlet例子。 实现实时推送数据到客户端。 服务器每隔30-500MS产生一个随机数

// Copyright (c) 2000 Just Objects B.V. <[e-mail]>
// Distributable under LGPL license. See terms of license at gnu.org.

package nl.justobjects.pushlet.core;

import nl.justobjects.pushlet.util.Log;
import nl.justobjects.pushlet.util.PushletException;

/**
 * Represents client pushlet session state.
 *
 * @author Just van den Broecke - Just Objects &copy;
 * @version $Id: Session.java,v 1.8 2007/11/23 14:33:07 justb Exp $
 */
public class Session implements Protocol, ConfigDefs {
	private Controller controller;
	private Subscriber subscriber;

	private String userAgent;
	private long LEASE_TIME_MILLIS = Config.getLongProperty(SESSION_TIMEOUT_MINS) * 60 * 1000;
	private volatile long timeToLive = LEASE_TIME_MILLIS;

	public static String[] FORCED_PULL_AGENTS = Config.getProperty(LISTEN_FORCE_PULL_AGENTS).split(",");

	private String address = "unknown";
	private String format = FORMAT_XML;

	private String id;

	/**
	 * Protected constructor as we create through factory method.
	 */
	protected Session() {
	}

	/**
	 * Create instance through factory method.
	 *
	 * @param anId a session id
	 * @return a Session object (or derived)
	 * @throws PushletException exception, usually misconfiguration
	 */
	public static Session create(String anId) throws PushletException {
		Session session;
		try {
			session = (Session) Config.getClass(SESSION_CLASS, "nl.justobjects.pushlet.core.Session").newInstance();
		} catch (Throwable t) {
			throw new PushletException("Cannot instantiate Session from config", t);
		}

		// Init session
		session.id = anId;
		session.controller = Controller.create(session);
		session.subscriber = Subscriber.create(session);
		return session;
	}

	/**
	 * Return (remote) Subscriber client's IP address.
	 */
	public String getAddress() {
		return address;
	}

	/**
	 * Return command controller.
	 */
	public Controller getController() {
		return controller;
	}

	/**
	 * Return Event format to send to client.
	 */
	public String getFormat() {
		return format;
	}

	/**
	 * Return (remote) Subscriber client's unique id.
	 */
	public String getId() {
		return id;
	}

	/**
	 * Return subscriber.
	 */
	public Subscriber getSubscriber() {
		return subscriber;
	}

	/**
	 * Return remote HTTP User-Agent.
	 */
	public String getUserAgent() {
		return userAgent;
	}

	/**
	 * Set address.
	 */
	protected void setAddress(String anAddress) {
		address = anAddress;
	}

	/**
	 * Set event format to encode.
	 */
	protected void setFormat(String aFormat) {
		format = aFormat;
	}

	/**
	 * Set client HTTP UserAgent.
	 */
	public void setUserAgent(String aUserAgent) {
		userAgent = aUserAgent;
	}

	/**
	 * Decrease time to live.
	 */
	public void age(long aDeltaMillis) {
		timeToLive -= aDeltaMillis;
	}

	/**
	 * Has session timed out?
	 */
	public boolean isExpired() {
		return timeToLive <= 0;
	}

	/**
	 * Keep alive by resetting TTL.
	 */
	public void kick() {
		timeToLive = LEASE_TIME_MILLIS;
	}

	public void start() {
		SessionManager.getInstance().addSession(this);
	}

	public void stop() {
		subscriber.stop();
		SessionManager.getInstance().removeSession(this);
	}

	/**
	 * Info.
	 */
	public void info(String s) {
		Log.info("S-" + this + ": " + s);
	}

	/**
	 * Exceptional print util.
	 */
	public void warn(String s) {
		Log.warn("S-" + this + ": " + s);
	}

	/**
	 * Exceptional print util.
	 */
	public void debug(String s) {
		Log.debug("S-" + this + ": " + s);
	}

	public String toString() {
		return getAddress() + "[" + getId() + "]";
	}
}

/*
 * $Log: Session.java,v $
 * Revision 1.8  2007/11/23 14:33:07  justb
 * core classes now configurable through factory
 *
 * Revision 1.7  2005/02/28 15:58:05  justb
 * added SimpleListener example
 *
 * Revision 1.6  2005/02/28 12:45:59  justb
 * introduced Command class
 *
 * Revision 1.5  2005/02/28 09:14:55  justb
 * sessmgr/dispatcher factory/singleton support
 *
 * Revision 1.4  2005/02/25 15:13:01  justb
 * session id generation more robust
 *
 * Revision 1.3  2005/02/21 16:59:08  justb
 * SessionManager and session lease introduced
 *
 * Revision 1.2  2005/02/21 12:32:28  justb
 * fixed publish event in Controller
 *
 * Revision 1.1  2005/02/21 11:50:46  justb
 * ohase1 of refactoring Subscriber into Session/Controller/Subscriber
 *

 *
 */