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: 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 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:  * Storage stores images in session, but expires them after a certain time. 
franta-hg@1:  * This expiration time defaults to 300 seconds, and can be changed by adding 
franta-hg@1:  * the timeout="xxx" parameter to <cewolf:img> and <cewolf:legend> tags.
franta-hg@1:  * 
franta-hg@1:  * @author brianf
franta-hg@1:  */
franta-hg@1: public class LongTermSessionStorage implements Storage
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:   /*
franta-hg@1:    * (non-Javadoc)
franta-hg@1:    * 
franta-hg@1:    * @see de.laures.cewolf.Storage#storeChartImage(de.laures.cewolf.ChartImage,
franta-hg@1:    *      javax.servlet.jsp.PageContext)
franta-hg@1:    */
franta-hg@1:   public String storeChartImage( ChartImage chartImage, PageContext pageContext ) throws CewolfException
franta-hg@1:   {
franta-hg@1:     HttpSession session = pageContext.getSession();
franta-hg@1:     SessionStorageGroup ssg = (SessionStorageGroup) session.getAttribute("CewolfCharts");
franta-hg@1:     if ( ssg == null )
franta-hg@1:     {
franta-hg@1:       ssg = new SessionStorageGroup();
franta-hg@1:       session.setAttribute("CewolfCharts", ssg);
franta-hg@1:     }
franta-hg@1:     String cid = getKey(chartImage);
franta-hg@1:     SessionStorageItem ssi = new SessionStorageItem(chartImage, cid, chartImage.getTimeoutTime());
franta-hg@1:     ssg.put(cid, ssi);
franta-hg@1: 
franta-hg@1:     return cid;
franta-hg@1:   }
franta-hg@1: 
franta-hg@1:   /*
franta-hg@1:    * (non-Javadoc)
franta-hg@1:    * 
franta-hg@1:    * @see de.laures.cewolf.Storage#getChartImage(java.lang.String,
franta-hg@1:    *      javax.servlet.http.HttpServletRequest)
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:     ChartImage chart = null;
franta-hg@1:     SessionStorageGroup ssg = (SessionStorageGroup) session.getAttribute("CewolfCharts");
franta-hg@1:     if ( ssg != null )
franta-hg@1:     {
franta-hg@1:       SessionStorageItem ssi = (SessionStorageItem) ssg.get(id);
franta-hg@1:       if ( ssi != null )
franta-hg@1:       {
franta-hg@1:         chart = ssi.getChart();
franta-hg@1:       }
franta-hg@1:     }
franta-hg@1: 
franta-hg@1:     return chart;
franta-hg@1:   }
franta-hg@1:   /*
franta-hg@1:    * (non-Javadoc)
franta-hg@1:    * 
franta-hg@1:    * @see de.laures.cewolf.Storage#init(javax.servlet.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:    * @see de.laures.cewolf.Storage#removeChartImage(java.lang.String, javax.servlet.jsp.PageContext)
franta-hg@1:    */
franta-hg@1:   public String removeChartImage(String cid, HttpServletRequest request) throws CewolfException {
franta-hg@1: 	  HttpSession session = request.getSession();
franta-hg@1: 	  // No session exit
franta-hg@1: 	  if (session == null)
franta-hg@1: 	  {
franta-hg@1: 		  return cid;
franta-hg@1: 	  }
franta-hg@1: 	  SessionStorageGroup ssg = (SessionStorageGroup) session.getAttribute("CewolfCharts");
franta-hg@1: 	  if ( ssg == null )
franta-hg@1: 	  {
franta-hg@1: 		  // No group exit
franta-hg@1: 		  return cid;
franta-hg@1: 	  }
franta-hg@1: 	  ssg.remove(cid);
franta-hg@1: 	  return cid;  
franta-hg@1:   }
franta-hg@1: }