diff -r 1612dbcec451 -r 639991d0808a java/cewolf-1.0/src/main/java/de/laures/cewolf/Storage.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/java/cewolf-1.0/src/main/java/de/laures/cewolf/Storage.java	Sat Feb 28 21:31:02 2009 +0100
@@ -0,0 +1,87 @@
+/* ================================================================
+ * 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;
+
+import javax.servlet.ServletContext;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpSession;
+import javax.servlet.jsp.PageContext;
+
+/**
+ * Pluggable storage. Implement this class to change the
+ * storage concept which Cewolf uses to store chart imanges and
+ * provide the implementation class name as init paramter <em>storage</em>
+ * for Cewolf servlet.
+ * @author glaures
+ */
+public interface Storage{
+	
+	/**
+	 * Stores a chart image.
+	 * @param cid the image to be stored
+	 * @param servletContext servletContext which might be needed
+	 * @return String the storage id which is used to find the image in storage
+	 */
+	public String storeChartImage(ChartImage chartImage, PageContext pageContext) throws CewolfException;
+  
+	/**
+	 * Retrieves a chart image.
+	 * @param id the id of the image
+	 * @param request the request
+	 * @return ChartImage the stored image instance
+	 */
+	public ChartImage getChartImage(String id, HttpServletRequest request);
+    
+	/**
+	 * Tests if a chart image is already available in thsi store..
+	 * @param chartImage the image to test
+	 * @param pageContext the pageContext
+	 * @return <code>true</code> if a stored instance of this image is availbale
+	 */
+	// public boolean contains(ChartImage chartImage, PageContext pageContext);
+	
+	/**
+	 * Returns the key for this 
+	 * @param chartImage
+	 * @return String
+	 */
+	// public String getKey(ChartImage chartImage);
+	
+	/**
+	 * Method init.
+	 * @param servletContext
+	 * @throws CewolfException
+	 */
+	public void init(ServletContext servletContext) throws CewolfException;
+
+
+	/**
+	 * Removes the image from the storage
+	 * @param imgId Image id
+	 * @param request Servlet request
+	 * @return Image id
+	 * @throws CewolfException
+	 */
+	public String removeChartImage(String imgId, HttpServletRequest request)
+			throws CewolfException;
+}