/*
Wotonomy: OpenStep design patterns for pure Java applications.
Copyright (C) 2003 Intersect Software Corp.

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library; if not, see http://www.gnu.org
*/

package net.wotonomy.web;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamClass;

import jakarta.servlet.http.HttpSession;

/**
 * An implementation of WOSessionStore that stores WOSessions inside of
 * HttpSessions, to take advantage of the servlet containers built-in
 * distribution capabilities.
 *
 * @author michael@mpowers.net
 * @author $Author: cgruber $
 * @version $Revision: 905 $
 */
public class WOServletSessionStore extends WOSessionStore {
	private static final String ServletSessionKey = "WOServletSessionStoreKey";

	/**
	 * This implementation currently does nothing and returns null, as we rely on
	 * the servlet container to dispose of the HttpSession which contains our
	 * WOSession.
	 */
	@Override
	public WOSession removeSessionWithID(String sessionID) {
		return null;
	}

	/**
	 * Returns the WOSession for the specified ID from the store. The sessionID
	 * parameter is ignored, and the session is removed from the store until
	 * saveSessionForContext is called.
	 */
	@Override
	public WOSession restoreSessionWithID(String sessionID, WORequest aRequest) {
		WOSession result = null;
		HttpSession servletSession = aRequest.servletRequest().getSession();
		if (servletSession != null) {
			try {
				result = (WOSession) servletSession.getAttribute(ServletSessionKey);
				if (result != null) {
					// if the servlet's class loader has changed, we need to reload
					if (result.getClass().getClassLoader() != WOApplication.application().getClass().getClassLoader()) {
						throw new ClassCastException(result.getClass().toString());
					}
				}
			} catch (ClassCastException exc) {
				// we're having an issue with the container's class loader:
				// try serializing and deserializing to see if it is reloaded correctly
				try {

					ByteArrayOutputStream bytes = new ByteArrayOutputStream();
					ObjectOutputStream output = new ObjectOutputStream(bytes);
					Object o = servletSession.getAttribute(ServletSessionKey);
					output.writeObject(o);
					output.flush();
					output.close();

					System.out.println(
							"WOServletSessionStore: reloaded session with size: " + bytes.toByteArray().length);

					ObjectInputStream input = new CustomObjectInputStream(new ByteArrayInputStream(bytes.toByteArray()),
							WOApplication.application().getClass().getClassLoader());

					o = input.readObject();
					input.close();

					// try it again
					result = (WOSession) o;
				} catch (Exception e) {
					e.printStackTrace();
					// give up: remove the attribute and allow a new session
					servletSession.removeAttribute(ServletSessionKey);
				}
			}

			if (result != null) {
				servletSession.removeAttribute(ServletSessionKey);
			}
		}
		// System.out.println( "restoreSessionWithID: " + sessionID + " : " + result );
		return result;
	}

	/**
	 * Places the context's session into the store.
	 */
	@Override
	public void saveSessionForContext(WOContext context) {
		// System.out.println( "saveSessionForContext: " + context + " : " +
		// context.session() );
		context.request().servletRequest().getSession(true).setAttribute(ServletSessionKey, context.session());
	}

	/**
	 * Needed to specify a class loader which may be different that the one used to
	 * load the ObjectInputStream class.
	 */
	private static class CustomObjectInputStream extends ObjectInputStream {
		ClassLoader loader;

		public CustomObjectInputStream(InputStream anInputStream, ClassLoader aClassLoader)
				throws java.io.IOException, java.io.StreamCorruptedException {
			super(anInputStream);
			loader = aClassLoader;
		}

		@Override
		protected Class<?> resolveClass(ObjectStreamClass v) throws IOException, ClassNotFoundException {
			return loader.loadClass(v.getName());
		}
	}
}

/*
 * $Log$ Revision 1.2 2006/02/19 01:44:02 cgruber Add xmlrpc files Remove jclark
 * and replace with dom4j and javax.xml.sax stuff Re-work dependencies and
 * imports so it all compiles.
 *
 * Revision 1.1 2006/02/16 13:22:22 cgruber Check in all sources in
 * eclipse-friendly maven-enabled packages.
 *
 * Revision 1.7 2003/01/22 23:00:32 mpowers Now keeping the most recent page
 * around.
 *
 * Revision 1.6 2003/01/21 17:53:16 mpowers Now handling reloading when wotonomy
 * is on the system class path.
 *
 * Revision 1.5 2003/01/15 19:50:49 mpowers Fixed issues with WOSession and
 * Serializable. Can now persist sessions between classloaders (hot swap of
 * class impls).
 *
 * Revision 1.3 2003/01/14 16:05:19 mpowers Removed extraneous printlns.
 *
 * Revision 1.2 2003/01/13 22:25:07 mpowers Request-response cycle is working
 * with session and page persistence.
 *
 * Revision 1.1 2003/01/07 20:48:24 mpowers Implemented WOSessionStore and
 * WOServletSessionStore.
 *
 *
 */