diff -r 1612dbcec451 -r 639991d0808a java/cewolf-1.0/src/main/java/de/laures/cewolf/storage/LongTermSessionStorage.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/java/cewolf-1.0/src/main/java/de/laures/cewolf/storage/LongTermSessionStorage.java	Sat Feb 28 21:31:02 2009 +0100
@@ -0,0 +1,122 @@
+/* ================================================================
+ * Cewolf : Chart enabling Web Objects Framework
+ * ================================================================
+ *
+ * Project Info:  http://cewolf.sourceforge.net
+ * Project Lead:  Guido Laures (guido@laures.de);
+ *
+ * (C) Copyright 2002, by Guido Laures
+ *
+ * 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+package de.laures.cewolf.storage;
+
+import java.io.Serializable;
+
+import javax.servlet.ServletContext;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpSession;
+import javax.servlet.jsp.PageContext;
+
+import de.laures.cewolf.CewolfException;
+import de.laures.cewolf.ChartImage;
+import de.laures.cewolf.Storage;
+import de.laures.cewolf.taglib.util.KeyGenerator;
+
+/**
+ * Storage stores images in session, but expires them after a certain time. 
+ * This expiration time defaults to 300 seconds, and can be changed by adding 
+ * the timeout="xxx" parameter to <cewolf:img> and <cewolf:legend> tags.
+ * 
+ * @author brianf
+ */
+public class LongTermSessionStorage implements Storage
+{
+ 
+  public final String getKey( ChartImage cid )
+  {
+    return String.valueOf(KeyGenerator.generateKey((Serializable) cid));
+  }
+
+  /*
+   * (non-Javadoc)
+   * 
+   * @see de.laures.cewolf.Storage#storeChartImage(de.laures.cewolf.ChartImage,
+   *      javax.servlet.jsp.PageContext)
+   */
+  public String storeChartImage( ChartImage chartImage, PageContext pageContext ) throws CewolfException
+  {
+    HttpSession session = pageContext.getSession();
+    SessionStorageGroup ssg = (SessionStorageGroup) session.getAttribute("CewolfCharts");
+    if ( ssg == null )
+    {
+      ssg = new SessionStorageGroup();
+      session.setAttribute("CewolfCharts", ssg);
+    }
+    String cid = getKey(chartImage);
+    SessionStorageItem ssi = new SessionStorageItem(chartImage, cid, chartImage.getTimeoutTime());
+    ssg.put(cid, ssi);
+
+    return cid;
+  }
+
+  /*
+   * (non-Javadoc)
+   * 
+   * @see de.laures.cewolf.Storage#getChartImage(java.lang.String,
+   *      javax.servlet.http.HttpServletRequest)
+   */
+  public ChartImage getChartImage( String id, HttpServletRequest request )
+  {
+    HttpSession session = request.getSession();
+    ChartImage chart = null;
+    SessionStorageGroup ssg = (SessionStorageGroup) session.getAttribute("CewolfCharts");
+    if ( ssg != null )
+    {
+      SessionStorageItem ssi = (SessionStorageItem) ssg.get(id);
+      if ( ssi != null )
+      {
+        chart = ssi.getChart();
+      }
+    }
+
+    return chart;
+  }
+  /*
+   * (non-Javadoc)
+   * 
+   * @see de.laures.cewolf.Storage#init(javax.servlet.ServletContext)
+   */
+  public void init( ServletContext servletContext ) throws CewolfException {
+  }
+
+  /**
+   * @see de.laures.cewolf.Storage#removeChartImage(java.lang.String, javax.servlet.jsp.PageContext)
+   */
+  public String removeChartImage(String cid, HttpServletRequest request) throws CewolfException {
+	  HttpSession session = request.getSession();
+	  // No session exit
+	  if (session == null)
+	  {
+		  return cid;
+	  }
+	  SessionStorageGroup ssg = (SessionStorageGroup) session.getAttribute("CewolfCharts");
+	  if ( ssg == null )
+	  {
+		  // No group exit
+		  return cid;
+	  }
+	  ssg.remove(cid);
+	  return cid;  
+  }
+}
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