com.vaadin.server.communication

Class JSR356WebsocketInitializer

java.lang.Object

com.vaadin.server.communication.JSR356WebsocketInitializer

All Implemented Interfaces:

EventListener, javax.servlet.ServletContextListener

@WebListener
public class JSR356WebsocketInitializer
extends Object
implements javax.servlet.ServletContextListener

Initializer class for JSR 356 websockets.

Websocket specification says that initialization of websocket end points should be done in the servlet context initialization phase. Some servers implement this strictly so that end points cannot be registered after the context initialization phase.

Note that WebListener is Servlet 3.0 API so this will not be run for older servers (unless added to web.xml), but these servers do not support JSR 356 websockets either.

Since:

7.5.0

Author:

Vaadin Ltd

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	JSR356WebsocketInitializer.FakeServletConfig "ServletConfig" which only provides information from a ServletRegistration and its ServletContext

Constructor Summary

Constructors

Constructor and Description
JSR356WebsocketInitializer()

Method Summary

Modifier and Type	Method and Description
void	contextDestroyed(javax.servlet.ServletContextEvent sce)
void	contextInitialized(javax.servlet.ServletContextEvent sce)
static String	getAttributeName(String servletName) Returns the name of the attribute in the servlet context where the pre-initialized Atmosphere object is stored
static void	initAtmosphereForVaadinServlet(javax.servlet.ServletRegistration servletRegistration, javax.servlet.ServletContext servletContext) Initializes Atmosphere for use with the given Vaadin servlet
protected boolean	isVaadinServlet(javax.servlet.ServletRegistration servletRegistration, javax.servlet.ServletContext servletContext) Tries to determine if the given servlet registration refers to a Vaadin servlet.

Methods inherited from class java.lang.Object

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

Constructor Detail

JSR356WebsocketInitializer

public JSR356WebsocketInitializer()

Method Detail

contextInitialized

public void contextInitialized(javax.servlet.ServletContextEvent sce)

Specified by:

contextInitialized in interface javax.servlet.ServletContextListener

initAtmosphereForVaadinServlet

public static void initAtmosphereForVaadinServlet(javax.servlet.ServletRegistration servletRegistration,
                                                  javax.servlet.ServletContext servletContext)

Initializes Atmosphere for use with the given Vaadin servlet

For JSR 356 websockets to work properly, the initialization must be done in the servlet context initialization phase.

Parameters:

servletRegistration - The servlet registration info for the servlet

servletContext -

getAttributeName

public static String getAttributeName(String servletName)

Returns the name of the attribute in the servlet context where the pre-initialized Atmosphere object is stored

Parameters:

servletName - The name of the servlet

Returns:

The attribute name which contains the initialized Atmosphere object

isVaadinServlet

protected boolean isVaadinServlet(javax.servlet.ServletRegistration servletRegistration,
                                  javax.servlet.ServletContext servletContext)

Tries to determine if the given servlet registration refers to a Vaadin servlet.

Parameters:

servletRegistration - The servlet registration info for the servlet

Returns:

false if the servlet is definitely not a Vaadin servlet, true otherwise

contextDestroyed

public void contextDestroyed(javax.servlet.ServletContextEvent sce)

Specified by:

contextDestroyed in interface javax.servlet.ServletContextListener