--- /dev/null
+package net.sourceforge.guacamole.net.basic;
+
+/*
+ * Guacamole - Clientless Remote Desktop
+ * Copyright (C) 2010 Michael Jumper
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import javax.servlet.Servlet;
+import javax.servlet.ServletContext;
+import javax.servlet.ServletContextEvent;
+import javax.servlet.ServletContextListener;
+import net.sourceforge.guacamole.GuacamoleException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Simple ServletContextListener which loads a WebSocket tunnel implementation
+ * if available, using the Servlet 3.0 API to dynamically load and install
+ * the tunnel servlet.
+ *
+ * Note that because Guacamole depends on the Servlet 2.5 API, and 3.0 may
+ * not be available or needed if WebSocket is not desired, the 3.0 API is
+ * detected and invoked dynamically via reflection.
+ *
+ * @author Michael Jumper
+ */
+public class WebSocketSupportLoader implements ServletContextListener {
+
+ private Logger logger = LoggerFactory.getLogger(WebSocketSupportLoader.class);
+
+ @Override
+ public void contextDestroyed(ServletContextEvent sce) {
+ }
+
+ @Override
+ public void contextInitialized(ServletContextEvent sce) {
+
+ try {
+
+ // Attempt to find WebSocket servlet
+ Class<Servlet> servlet = (Class<Servlet>) GuacamoleClassLoader.getInstance().findClass(
+ "net.sourceforge.guacamole.net.basic.BasicGuacamoleWebSocketTunnelServlet"
+ );
+
+ // Dynamically add servlet IF SERVLET 3.0 API AVAILABLE!
+ try {
+
+ // Get servlet registration class
+ Class regClass = Class.forName("javax.servlet.ServletRegistration");
+
+ // Get and invoke addServlet()
+ Method addServlet = ServletContext.class.getMethod("addServlet", String.class, Class.class);
+ Object reg = addServlet.invoke(sce.getServletContext(), "WebSocketTunnel", servlet);
+
+ // Get and invoke addMapping()
+ Method addMapping = regClass.getMethod("addMapping", String[].class);
+ addMapping.invoke(reg, (Object) new String[]{"/websocket-tunnel"});
+
+ // If we succesfully load and register the WebSocket tunnel servlet,
+ // WebSocket is supported.
+ logger.info("WebSocket support found and loaded.");
+
+ }
+
+ // Servlet API 3.0 unsupported
+ catch (ClassNotFoundException e) {
+ logger.error("Servlet API 3.0 not found.", e);
+ }
+ catch (NoSuchMethodException e) {
+ logger.error("Servlet API 3.0 found, but incomplete.", e);
+ }
+
+ // Servlet API 3.0 found, but errors during use
+ catch (IllegalAccessException e) {
+ logger.error("Unable to load WebSocket tunnel servlet.", e);
+ }
+ catch (InvocationTargetException e) {
+ logger.error("Internal error loading WebSocket tunnel servlet.", e);
+ }
+
+ }
+
+ // If no such servlet class, WebSocket support not present
+ catch (ClassNotFoundException e) {
+ logger.info("WebSocket support not found.");
+ }
+
+ // Log all GuacamoleExceptions
+ catch (GuacamoleException e) {
+ logger.error("Unable to load/detect WebSocket support.", e);
+ }
+
+ }
+
+}
+