com.gisgraphy.webapp.listener
Class UserCounterListener

java.lang.Object
  com.gisgraphy.webapp.listener.UserCounterListener

All Implemented Interfaces:

java.util.EventListener, javax.servlet.http.HttpSessionAttributeListener, javax.servlet.ServletContextListener

public class UserCounterListener
extends java.lang.Object
implements javax.servlet.ServletContextListener, javax.servlet.http.HttpSessionAttributeListener

UserCounterListener class used to count the current number of active users for the applications. Does this by counting how many user objects are stuffed into the session. It Also grabs these users and exposes them in the servlet context.

Author:

Matt Raible

Field Summary

static java.lang.String	COUNT_KEY Name of user counter variable
static java.lang.String	EVENT_KEY The default event we're looking to trap.
static java.lang.String	USERS_KEY Name of users Set in the ServletContext

Constructor Summary

UserCounterListener()

Method Summary

void	attributeAdded(javax.servlet.http.HttpSessionBindingEvent event) This method is designed to catch when user's login and record their name
void	attributeRemoved(javax.servlet.http.HttpSessionBindingEvent event) When user's logout, remove their name from the hashMap
void	attributeReplaced(javax.servlet.http.HttpSessionBindingEvent event) Needed for Acegi Security 1.0, as it adds an anonymous user to the session and then replaces it after authentication.
void	contextDestroyed(javax.servlet.ServletContextEvent event) Set the servletContext, users and counter to null
void	contextInitialized(javax.servlet.ServletContextEvent sce) Initialize the context

Methods inherited from class java.lang.Object

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

Field Detail

COUNT_KEY

public static final java.lang.String COUNT_KEY

Name of user counter variable

See Also:

Constant Field Values

USERS_KEY

public static final java.lang.String USERS_KEY

Name of users Set in the ServletContext

See Also:

Constant Field Values

EVENT_KEY

public static final java.lang.String EVENT_KEY

The default event we're looking to trap.

See Also:

Constant Field Values

Constructor Detail

UserCounterListener

public UserCounterListener()

Method Detail

contextInitialized

public void contextInitialized(javax.servlet.ServletContextEvent sce)

Initialize the context

Specified by:

contextInitialized in interface javax.servlet.ServletContextListener

Parameters:

sce - the event

contextDestroyed

public void contextDestroyed(javax.servlet.ServletContextEvent event)

Set the servletContext, users and counter to null

Specified by:

contextDestroyed in interface javax.servlet.ServletContextListener

Parameters:

event - The servletContextEvent

attributeAdded

public void attributeAdded(javax.servlet.http.HttpSessionBindingEvent event)

This method is designed to catch when user's login and record their name

Specified by:

attributeAdded in interface javax.servlet.http.HttpSessionAttributeListener

Parameters:

event - the event to process

See Also:

HttpSessionAttributeListener.attributeAdded(javax.servlet.http.HttpSessionBindingEvent)

attributeRemoved

public void attributeRemoved(javax.servlet.http.HttpSessionBindingEvent event)

When user's logout, remove their name from the hashMap

Specified by:

attributeRemoved in interface javax.servlet.http.HttpSessionAttributeListener

Parameters:

event - the session binding event

See Also:

HttpSessionAttributeListener.attributeRemoved(javax.servlet.http.HttpSessionBindingEvent)

attributeReplaced

public void attributeReplaced(javax.servlet.http.HttpSessionBindingEvent event)

Needed for Acegi Security 1.0, as it adds an anonymous user to the session and then replaces it after authentication. http://forum.springframework.org/showthread.php?p=63593

Specified by:

attributeReplaced in interface javax.servlet.http.HttpSessionAttributeListener

Parameters:

event - the session binding event

See Also:

HttpSessionAttributeListener.attributeReplaced(javax.servlet.http.HttpSessionBindingEvent)