franta-hg@1: /* ================================================================
franta-hg@1:  * Cewolf : Chart enabling Web Objects Framework
franta-hg@1:  * ================================================================
franta-hg@1:  *
franta-hg@1:  * Project Info:  http://cewolf.sourceforge.net
franta-hg@1:  * Project Lead:  Guido Laures (guido@laures.de);
franta-hg@1:  *
franta-hg@1:  * (C) Copyright 2002, by Guido Laures
franta-hg@1:  *
franta-hg@1:  * This library is free software; you can redistribute it and/or modify it under the terms
franta-hg@1:  * of the GNU Lesser General Public License as published by the Free Software Foundation;
franta-hg@1:  * either version 2.1 of the License, or (at your option) any later version.
franta-hg@1:  *
franta-hg@1:  * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
franta-hg@1:  * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
franta-hg@1:  * See the GNU Lesser General Public License for more details.
franta-hg@1:  *
franta-hg@1:  * You should have received a copy of the GNU Lesser General Public License along with this
franta-hg@1:  * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
franta-hg@1:  * Boston, MA 02111-1307, USA.
franta-hg@1:  */
franta-hg@1: 
franta-hg@1: package de.laures.cewolf.storage;
franta-hg@1: 
franta-hg@1: import java.io.Serializable;
franta-hg@1: 
franta-hg@1: import javax.servlet.ServletContext;
franta-hg@1: import javax.servlet.http.HttpServletRequest;
franta-hg@1: import javax.servlet.http.HttpSession;
franta-hg@1: import javax.servlet.jsp.PageContext;
franta-hg@1: 
franta-hg@1: import org.apache.commons.logging.Log;
franta-hg@1: import org.apache.commons.logging.LogFactory;
franta-hg@1: 
franta-hg@1: import de.laures.cewolf.CewolfException;
franta-hg@1: import de.laures.cewolf.ChartImage;
franta-hg@1: import de.laures.cewolf.Storage;
franta-hg@1: import de.laures.cewolf.taglib.util.KeyGenerator;
franta-hg@1: 
franta-hg@1: /**
franta-hg@1:  * @author glaures
franta-hg@1:  */
franta-hg@1: public abstract class AbstractSessionStorage implements Storage
franta-hg@1: {
franta-hg@1: 
franta-hg@1:   private static final Log log = LogFactory.getLog(AbstractSessionStorage.class);
franta-hg@1: 
franta-hg@1:   /**
franta-hg@1:    * @see de.laures.cewolf.Storage#storeChartImage(ChartImage, ServletContext)
franta-hg@1:    */
franta-hg@1:   public String storeChartImage( ChartImage cid, PageContext pageContext ) throws CewolfException
franta-hg@1:   {
franta-hg@1:     if ( contains(cid, pageContext) )
franta-hg@1:     {
franta-hg@1:       return getKey(cid);
franta-hg@1:     }
franta-hg@1:     log.debug("storing chart " + cid);
franta-hg@1:     final HttpSession session = pageContext.getSession();
franta-hg@1:     //String key = getKey(cid);
franta-hg@1:     return storeChartImage(cid, session);
franta-hg@1:   }
franta-hg@1: 
franta-hg@1: 
franta-hg@1:   /**
franta-hg@1:    * @see de.laures.cewolf.Storage#getChartImage(String)
franta-hg@1:    */
franta-hg@1:   public ChartImage getChartImage( String id, HttpServletRequest request )
franta-hg@1:   {
franta-hg@1:     HttpSession session = request.getSession();
franta-hg@1:     return (ChartImage) session.getAttribute(id);
franta-hg@1:   }
franta-hg@1: 
franta-hg@1:   public boolean contains( ChartImage cid, PageContext pageContext )
franta-hg@1:   {
franta-hg@1:     return pageContext.getSession().getAttribute(getKey(cid)) != null;
franta-hg@1:   }
franta-hg@1: 
franta-hg@1:   public final String getKey( ChartImage cid )
franta-hg@1:   {
franta-hg@1:     return String.valueOf(KeyGenerator.generateKey((Serializable) cid));
franta-hg@1:   }
franta-hg@1: 
franta-hg@1:   protected String storeChartImage( ChartImage cid, HttpSession session ) throws CewolfException
franta-hg@1:   {
franta-hg@1:     final String sessionKey = getKey(cid);
franta-hg@1:     synchronized (session)
franta-hg@1:     {
franta-hg@1:       session.setAttribute(sessionKey, getCacheObject(cid));
franta-hg@1:     }
franta-hg@1:     return sessionKey;
franta-hg@1:   }
franta-hg@1:   
franta-hg@1: 	/**
franta-hg@1: 	 */
franta-hg@1: 	public String removeChartImage(String imgKey, HttpServletRequest request)
franta-hg@1: 			throws CewolfException {
franta-hg@1: 		final HttpSession session = request.getSession();
franta-hg@1: 		if (session == null)
franta-hg@1: 		{
franta-hg@1: 			return imgKey;
franta-hg@1: 		}
franta-hg@1: 		return removeChartImage(imgKey, session);		
franta-hg@1: 	}
franta-hg@1: 
franta-hg@1: 	/**
franta-hg@1: 	 * @param cid
franta-hg@1: 	 * @param session
franta-hg@1: 	 * @return
franta-hg@1: 	 * @throws CewolfException
franta-hg@1: 	 */
franta-hg@1: 	protected String removeChartImage(String cid, HttpSession session)
franta-hg@1: 			throws CewolfException {
franta-hg@1: 		synchronized (session) {
franta-hg@1: 			session.removeAttribute(cid);
franta-hg@1: 		}
franta-hg@1: 		return cid;
franta-hg@1: 	}
franta-hg@1: 
franta-hg@1:   protected abstract Object getCacheObject( ChartImage cid ) throws CewolfException;
franta-hg@1: 
franta-hg@1:   /**
franta-hg@1:    * @see de.laures.cewolf.Storage#init(ServletContext)
franta-hg@1:    */
franta-hg@1:   public void init( ServletContext servletContext ) throws CewolfException
franta-hg@1:   {
franta-hg@1:   }
franta-hg@1:   
franta-hg@1: 
franta-hg@1: 
franta-hg@1: }