com.vaadin.terminal.gwt.server
Class GAEApplicationServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          com.vaadin.terminal.gwt.server.AbstractApplicationServlet
              com.vaadin.terminal.gwt.server.ApplicationServlet
                  com.vaadin.terminal.gwt.server.GAEApplicationServlet

All Implemented Interfaces:

Constants, Serializable, Servlet, ServletConfig

public class GAEApplicationServlet
extends ApplicationServlet

ApplicationServlet to be used when deploying to Google App Engine, in web.xml:

      <servlet>
              <servlet-name>HelloWorld</servlet-name>
              <servlet-class>com.vaadin.terminal.gwt.server.GAEApplicationServlet</servlet-class>
              <init-param>
                      <param-name>application</param-name>
                      <param-value>com.vaadin.demo.HelloWorld</param-value>
              </init-param>
      </servlet>
 

Session support must be enabled in appengine-web.xml:

      <sessions-enabled>true</sessions-enabled>
 

Appengine datastore cleanup can be invoked by calling one of the applications with an additional path "/CLEAN". This can be set up as a cron-job in cron.xml (see appengine documentation for more information):

 <cronentries>
   <cron>
     <url>/HelloWorld/CLEAN</url>
     <description>Clean up sessions</description>
     <schedule>every 2 hours</schedule>
   </cron>
 </cronentries>
 

It is recommended (but not mandatory) to extract themes and widgetsets and have App Engine server these statically. Extract VAADIN folder (and it's contents) 'next to' the WEB-INF folder, and add the following to appengine-web.xml:

      <static-files>
           <include path="/VAADIN/**" />
      </static-files>
 

Additional limitations:

• Do not change application state when serving an ApplicationResource.
• Avoid changing application state in transaction handlers, unless you're confident you fully understand the synchronization issues in App Engine.
• The application remains locked while uploading - no progressbar is possible.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.vaadin.terminal.gwt.server.AbstractApplicationServlet

AbstractApplicationServlet.RequestError, AbstractApplicationServlet.RequestType

Field Summary

Fields inherited from interface com.vaadin.terminal.gwt.server.Constants

AJAX_UIDL_URI, DEFAULT_BUFFER_SIZE, DEFAULT_THEME_CACHETIME, DEFAULT_THEME_NAME, DEFAULT_WIDGETSET, ERROR_NO_ROOT_FOUND, INVALID_SECURITY_KEY_MSG, MAX_BUFFER_SIZE, NOT_PRODUCTION_MODE_INFO, PARAMETER_VAADIN_RESOURCES, PARAMETER_WIDGETSET, PORTAL_PARAMETER_VAADIN_RESOURCE_PATH, PORTAL_PARAMETER_VAADIN_THEME, PORTAL_PARAMETER_VAADIN_WIDGETSET, SERVLET_PARAMETER_DISABLE_XSRF_PROTECTION, SERVLET_PARAMETER_PRODUCTION_MODE, SERVLET_PARAMETER_RESOURCE_CACHE_TIME, THEME_DIRECTORY_PATH, URL_PARAMETER_CLOSE_APPLICATION, URL_PARAMETER_REPAINT_ALL, URL_PARAMETER_RESTART_APPLICATION, URL_PARAMETER_THEME, WARNING_RESOURCE_CACHING_TIME_NOT_NUMERIC, WARNING_XSRF_PROTECTION_DISABLED, WIDGETSET_DIRECTORY_PATH, WIDGETSET_MISMATCH_INFO

Constructor Summary

GAEApplicationServlet()

Method Summary

protected ApplicationContext	getApplicationContext(HttpServletRequest request, MemcacheService memcache)
protected void	sendCriticalErrorNotification(HttpServletRequest request, HttpServletResponse response)
protected void	sendDeadlineExceededNotification(HttpServletRequest request, HttpServletResponse response)
protected void	sendNotSerializableNotification(HttpServletRequest request, HttpServletResponse response)
protected void	service(HttpServletRequest request, HttpServletResponse response) Receives standard HTTP requests from the public service method and dispatches them.

Methods inherited from class com.vaadin.terminal.gwt.server.ApplicationServlet

getApplicationClass, getNewApplication, init

Methods inherited from class com.vaadin.terminal.gwt.server.AbstractApplicationServlet

createCommunicationManager, createWrappedRequest, criticalNotification, getApplicationContext, getApplicationProperty, getApplicationUrl, getClassLoader, getDefaultTheme, getDeploymentConfiguration, getExistingApplication, getRequestPathInfo, getRequestType, getResourceCacheTime, getResourceLocation, getResourcePath, getStaticFilesLocation, getSystemMessages, getSystemMessages, getSystemProperty, isAllowedVAADINResourceUrl, isProductionMode, safeEscapeForHtml, stripSpecialChars

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doGet, doHead, doOptions, doPost, doPut, doTrace, getLastModified, service

Methods inherited from class javax.servlet.GenericServlet

destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

GAEApplicationServlet

public GAEApplicationServlet()

Method Detail

sendDeadlineExceededNotification

protected void sendDeadlineExceededNotification(HttpServletRequest request,
                                                HttpServletResponse response)
                                         throws IOException

Throws:

IOException

sendNotSerializableNotification

protected void sendNotSerializableNotification(HttpServletRequest request,
                                               HttpServletResponse response)
                                        throws IOException

Throws:

IOException

sendCriticalErrorNotification

protected void sendCriticalErrorNotification(HttpServletRequest request,
                                             HttpServletResponse response)
                                      throws IOException

Throws:

IOException

service

protected void service(HttpServletRequest request,
                       HttpServletResponse response)
                throws ServletException,
                       IOException

Description copied from class: AbstractApplicationServlet

Receives standard HTTP requests from the public service method and dispatches them.

Overrides:

service in class AbstractApplicationServlet

Parameters:

request - the object that contains the request the client made of the servlet.

response - the object that contains the response the servlet returns to the client.

Throws:

ServletException - if an input or output error occurs while the servlet is handling the TRACE request.

IOException - if the request for the TRACE cannot be handled.

getApplicationContext

protected ApplicationContext getApplicationContext(HttpServletRequest request,
                                                   MemcacheService memcache)