diff -r 1612dbcec451 -r 639991d0808a java/cewolf-1.0/src/main/java/de/laures/cewolf/CewolfRenderer.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/java/cewolf-1.0/src/main/java/de/laures/cewolf/CewolfRenderer.java	Sat Feb 28 21:31:02 2009 +0100
@@ -0,0 +1,265 @@
+/* ================================================================
+ * 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 java.io.IOException;
+import java.io.OutputStream;
+import java.io.Writer;
+import java.util.Enumeration;
+
+import javax.servlet.ServletConfig;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import de.laures.cewolf.util.RenderingHelper;
+
+/**
+ * The rendering servlet of Cewolf. It is resposible for writing an entire chart
+ * img into the response stream of the client. Everything needed for this is
+ * prepared already by the ChartImgTag resp. LegendTag. The ID of a chart image
+ * is passed to this servlet as a request parameter. After that the image object
+ * is retrieved from the server side session based image cache. This servlet
+ * must be configured in web.xml of the web application in order to use Cewolf
+ * services. The servlet's URL relative to the web apps root is used as the
+ * renderer attribute of the ChartImgTag resp. LegendTag in the JSP page.
+ * 
+ * @see de.laures.cewolf.taglib.tags.ChartImgTag
+ * @see de.laures.cewolf.taglib.tags.LegendTag
+ * @author Guido Laures
+ * @since 0.1
+ */
+public class CewolfRenderer extends HttpServlet implements WebConstants
+{
+
+  public static final String  INIT_CONFIG  = "CewolfRenderer_Init_Config";
+  private static final String STATE        = "state";
+  private boolean             debugged     = false;
+  private int                 requestCount = 0;
+  private Byte 					lock = Byte.valueOf("0");
+  private Configuration       config       = null;
+
+  public void init( ServletConfig servletCfg ) throws ServletException
+  {
+    super.init(servletCfg);
+    
+    //Store init config params for processing by the Configuration
+    servletCfg.getServletContext().setAttribute(INIT_CONFIG, servletCfg);
+    config = Configuration.getInstance(servletCfg.getServletContext());
+    
+    if (config != null)
+      this.debugged = config.isDebugged();
+    else
+      this.debugged = false;
+  }
+
+  /**
+   * Processes HTTP <code>GET</code> request. Renders the chart or the lengend
+   * into the client's response stream.
+   * 
+   * @param request
+   *          servlet request
+   * @param response
+   *          servlet response
+   * @throws ServletException
+   *           when the production of data could not be handled by the
+   *           configured DatasetProcuder
+   */
+  
+  public void printParameters(HttpServletRequest request)
+  {
+    Enumeration enumeration = request.getParameterNames();
+    while (enumeration.hasMoreElements())
+    {
+      String cur = (String)enumeration.nextElement();
+      Object obj = request.getParameter(cur);
+      
+      log("Request Parameter -> " + cur + " Value -> " + obj.toString());
+    }
+  }
+  
+  protected void doGet( HttpServletRequest request, HttpServletResponse response ) throws ServletException, IOException
+  {
+    if ( debugged )
+    {
+      logRequest(request);
+    }
+    addHeaders(response);
+    if ( request.getParameter(STATE) != null || !request.getParameterNames().hasMoreElements() )
+    {
+      requestState(response);
+      return;
+    }
+    synchronized (lock) {
+    	requestCount++;
+	}
+    
+    int width = 400;
+    int height = 400;
+    boolean removeAfterRendering = false;
+    if ( request.getParameter(REMOVE_AFTER_RENDERING) != null )
+    {
+    	removeAfterRendering = true;
+    }
+    if ( request.getParameter(WIDTH_PARAM) != null )
+    {
+      width = Integer.parseInt(request.getParameter(WIDTH_PARAM));
+    }
+    if ( request.getParameter(HEIGHT_PARAM) != null )
+    {
+      height = Integer.parseInt(request.getParameter(HEIGHT_PARAM));
+    }
+
+    // determine the cache key
+    String imgKey = request.getParameter(IMG_PARAM);
+    if ( imgKey == null )
+    {
+      logAndRenderException(new ServletException("no '" + IMG_PARAM + "' parameter provided for Cewolf servlet."), response, width, height);
+      return;
+    }
+    Storage storage = config.getStorage();
+    ChartImage chartImage = storage.getChartImage(imgKey, request);
+    if ( chartImage == null )
+    {
+      renderImageExpiry(response, width, height);
+      return;
+    }
+    // send the img
+    try
+    {
+      long start = System.currentTimeMillis();
+      // response.setContentType(cid.getMimeType());
+      final int size = chartImage.getSize();
+      response.setContentType(chartImage.getMimeType());
+      response.setContentLength(size);
+      response.setBufferSize(size);
+      response.setStatus(HttpServletResponse.SC_OK);
+      response.getOutputStream().write(chartImage.getBytes());
+      long last = System.currentTimeMillis() - start;
+      if ( debugged )
+      {
+        log("creation time for chart " + imgKey + ": " + last + "ms.");
+      }
+    }
+    catch (Throwable t)
+    {
+      logAndRenderException(t, response, width, height);
+    }
+    finally
+    {
+    	if (removeAfterRendering)
+    	{
+    		try {
+				storage.removeChartImage(imgKey , request);
+			} catch (CewolfException e) {
+				log("Removal of image failed", e);
+			}
+    	}
+    }
+  }
+
+  /**
+   * Method addHeaders.
+   * 
+   * @param response
+   */
+  private void addHeaders( HttpServletResponse response )
+  {
+    response.setDateHeader("Expires", System.currentTimeMillis());
+  }
+
+  /**
+   * Method requestState.
+   * 
+   * @param request
+   * @param response
+   */
+  private void requestState( HttpServletResponse response ) throws IOException
+  {
+    Writer writer = response.getWriter();
+    writer.write("<HTML><BODY>");
+    /*
+     * StateDescriptor sd = (StateDescriptor)
+     * ChartImageCacheFactory.getChartImageBase( getServletContext());
+     * writer.write(HTMLStateTable.getStateTable(sd));
+     */
+    writer.write("<b>Cewolf servlet up and running.</b><br>");
+    writer.write("Requests served so far: " + requestCount);
+    writer.write("</HTML></BODY>");
+    writer.close();
+  }
+
+  private void logAndRenderException( Throwable ex, HttpServletResponse response, int width, int height ) throws IOException
+  {
+    log(ex.getMessage(), ex);
+    response.setContentType("image/jpg");
+    OutputStream out = response.getOutputStream();
+    RenderingHelper.renderException(ex, width, height, out);
+    out.close();
+  }
+
+  /**
+   * Method renderImageExpiry.
+   * 
+   * @param response
+   * @param width
+   * @param height
+   */
+  private void renderImageExpiry( HttpServletResponse response, int width, int height ) throws IOException
+  {
+    response.setContentType("image/jpg");
+    OutputStream out = response.getOutputStream();
+    RenderingHelper.renderMessage("This chart has expired. Please reload.", width, height, out);
+    out.close();
+  }
+
+  private void logRequest( HttpServletRequest request ) throws IOException
+  {
+    log("Cewolf request:");
+    log("Actual Request values:");
+    printParameters(request);
+    Enumeration headerNames = request.getHeaderNames();
+    while ( headerNames.hasMoreElements() )
+    {
+      String name = (String) headerNames.nextElement();
+      Enumeration values = request.getHeaders(name);
+      StringBuffer value = new StringBuffer();
+      while ( values.hasMoreElements() )
+      {
+        value.append((String) values.nextElement() + ",");
+      }
+      // cut last comma
+      if ( value.length() > 0 )
+        value.setLength(value.length() - 1);
+      log(name + ": " + value);
+    }
+  //  InputStream body = request.getInputStream();
+ //   byte[] bodyData = new byte[body.available()];
+ //   body.read(bodyData);
+ //   body.close();
+ //   log(new String(bodyData));
+
+  }
+
+}
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