Javadocs, init servlets, added support for images.

git-svn-id: http://svn.igniterealtime.org/svn/repos/messenger/trunk@463 b35dd754-fafc-0310-a699-88a17e54d16e

src/java/org/jivesoftware/messenger/container/PluginServlet.java

@@ -22,15 +22,27 @@ import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 import javax.servlet.ServletException;
 import javax.servlet.ServletConfig;
-import java.io.IOException;
-import java.io.File;
+import javax.servlet.ServletOutputStream;
+import java.io.*;
 import java.util.Map;
 import java.util.List;
 import java.util.HashMap;
 import java.util.concurrent.ConcurrentHashMap;
 
 /**
+ * The plugin servlet acts as a proxy for web requests (in the admin console)
+ * to plugins. Since plugins can be dynamically loaded and live in a different place
+ * than normal Jive Messenger admin console files, it's not possible to have them
+ * added to the normal Jive Messenger admin console web app directory.<p>
  *
+ * The servlet listens for requests in the form <tt>/plugins/[pluginName]/[JSP File]</tt>
+ * (e.g. <tt>/plugins/foo/example.jsp</tt>). It also listens for image requests in the
+ * the form <tt>/plugins/[pluginName]/images/*.png|gif</tt> (e.g.
+ * <tt>/plugins/foo/images/example.gif</tt>).<p>
+ *
+ * JSP files must be compiled and available via the plugin's class loader. The mapping
+ * between JSP name and servlet class files is defined in [pluginName]/web/web.xml.
+ * Typically, this file is auto-generated by the JSP compiler when packaging the plugin.
  *
  * @author Matt Tucker
  */
@@ -38,9 +50,11 @@ public class PluginServlet extends HttpServlet {
 
     private static Map<String,HttpServlet> servlets;
     private static File pluginDirectory;
+    private static ServletConfig servletConfig;
 
     public void init(ServletConfig config) throws ServletException {
         super.init(config);
+        servletConfig = config;
         servlets = new ConcurrentHashMap<String,HttpServlet>();
         pluginDirectory = new File(JiveGlobals.getMessengerHome(), "plugins");
     }
@@ -60,7 +74,7 @@ public class PluginServlet extends HttpServlet {
             }
             // Handle image requests.
             else if (pathInfo.endsWith(".gif") || pathInfo.endsWith(".png")) {
-                handleImage(pathInfo, request, response);
+                handleImage(pathInfo, response);
             }
             // Anything else results in a 404.
             else {
@@ -101,15 +115,18 @@ public class PluginServlet extends HttpServlet {
                 Class servletClass = classMap.get(name);
                 Object instance = servletClass.newInstance();
                 if (instance instanceof HttpServlet) {
+                    // Initialize the servlet then add it to the map..
+                    ((HttpServlet)instance).init(servletConfig);
                     servlets.put(pluginName + url, (HttpServlet)instance);
                 }
+                else {
+                    Log.warn("Could not load " + (pluginName + url) + ": not a servlet.");
+                }
             }
         }
         catch (Throwable e) {
             e.printStackTrace();
         }
-
-        //plugin.getClass().getClassLoader().loadClass("");
     }
 
     /**
@@ -118,10 +135,11 @@ public class PluginServlet extends HttpServlet {
      * servlet is found, a 404 error is returned.
      *
      * @param pathInfo the extra path info.
-     * @param request
-     * @param response
-     * @throws ServletException
-     * @throws IOException
+     * @param request the request object.
+     * @param response the response object.
+     * @throws ServletException if a servlet exception occurs while handling the
+     *      request.
+     * @throws IOException if an IOException occurs while handling the request.
      */
     private void handleJSP(String pathInfo, HttpServletRequest request,
             HttpServletResponse response) throws ServletException, IOException
@@ -139,11 +157,49 @@ public class PluginServlet extends HttpServlet {
         }
     }
 
-    private void handleImage(String pathInfo, HttpServletRequest request,
-            HttpServletResponse response) throws ServletException, IOException
+    /**
+     * Handles a request for an image.
+     *
+     * @param pathInfo the extra path info.
+     * @param response the response object.
+     * @throws IOException if an IOException occurs while handling the request.
+     */
+    private void handleImage(String pathInfo, HttpServletResponse response) throws IOException
     {
+        File image = new File(pluginDirectory, pathInfo.replaceAll("/", File.separator));
+        if (!image.exists()) {
             response.setStatus(HttpServletResponse.SC_NOT_FOUND);
             return;
         }
+        else {
+            // Content type will be GIF or PNG.
+            String contentType = "image/gif";
+            if (pathInfo.endsWith(".png")) {
+                contentType = "image/png";
+            }
+            response.setHeader("Content-disposition", "filename=\"" + image + "\";");
+            response.setContentType(contentType);
+            // Write out the image to the user.
+            InputStream in = null;
+            ServletOutputStream out = null;
+            try {
+                in = new BufferedInputStream(new FileInputStream(image));
+                out = response.getOutputStream();
 
+                // Set the size of the file.
+                response.setContentLength((int)image.length());
+
+                // Use a 1K buffer.
+                byte[] buf = new byte[1024];
+                int len;
+                while ((len=in.read(buf)) != -1) {
+                    out.write(buf, 0, len);
+                }
+            }
+            finally {
+                try { in.close(); } catch (Exception ignored) {}
+                try { out.close(); } catch (Exception ignored) {}
+            }
+        }
+    }
 }
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