GUAC-867: Add periodic keep-alive ping to ensure the session does not perish while a connection is active.

guacamole/src/main/java/org/glyptodon/guacamole/net/basic/SessionKeepAlive.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2014 Glyptodon LLC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package org.glyptodon.guacamole.net.basic;
+
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import org.glyptodon.guacamole.net.auth.UserContext;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Dummy servlet which provides an endpoint for arbitrary requests intended to
+ * simply keep the HTTP session from expiring.
+ *
+ * @author Michael Jumper
+ */
+public class SessionKeepAlive extends RestrictedHttpServlet {
+
+    /**
+     * Logger for this class.
+     */
+    private final Logger logger = LoggerFactory.getLogger(SessionKeepAlive.class);
+
+    @Override
+    protected void restrictedService(
+            UserContext context,
+            HttpServletRequest request, HttpServletResponse response) {
+
+        // Do nothing
+        logger.trace("Keep-alive signal received.");
+        
+    }
+
+}