org.springframework.web.util

Class WebAppRootListener

java.lang.Object

org.springframework.web.util.WebAppRootListener

All Implemented Interfaces:

EventListener, ServletContextListener

public class WebAppRootListener
extends Object
implements ServletContextListener

Listener that sets a system property to the web application root directory. The key of the system property can be defined with the "webAppRootKey" init parameter at the servlet context level (i.e. context-param in web.xml), the default key is "webapp.root".

Can be used for toolkits that support substitution with system properties (i.e. System.getProperty values), like log4j's "${key}" syntax within log file locations.

Note: This listener should be placed before ContextLoaderListener in web.xml, at least when used for log4j. Log4jConfigListener sets the system property implicitly, so there's no need for this listener in addition to it.

WARNING: Some containers, e.g. Tomcat, do NOT keep system properties separate per web app. You have to use unique "webAppRootKey" context-params per web app then, to avoid clashes. Other containers like Resin do isolate each web app's system properties: Here you can use the default key (i.e. no "webAppRootKey" context-param at all) without worrying.

WARNING: The WAR file containing the web application needs to be expanded to allow for setting the web app root system property. This is by default not the case when a WAR file gets deployed to WebLogic, for example. Do not use this listener in such an environment!

Since:

18.04.2003

Author:

Juergen Hoeller

See Also:

WebUtils.setWebAppRootSystemProperty(javax.servlet.ServletContext), System.getProperty(java.lang.String)

Constructor Summary

Constructors

Constructor and Description
WebAppRootListener()

Method Summary

Modifier and Type	Method and Description
void	contextDestroyed(ServletContextEvent event) Receives notification that the ServletContext is about to be shut down.
void	contextInitialized(ServletContextEvent event) Receives notification that the web application initialization process is starting.

Methods inherited from class java.lang.Object

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

Constructor Detail

WebAppRootListener

public WebAppRootListener()

Method Detail

contextInitialized

public void contextInitialized(ServletContextEvent event)

Description copied from interface: javax.servlet.ServletContextListener

Receives notification that the web application initialization process is starting.

All ServletContextListeners are notified of context initialization before any filters or servlets in the web application are initialized.

Specified by:

contextInitialized in interface ServletContextListener

Parameters:

event - the ServletContextEvent containing the ServletContext that is being initialized

contextDestroyed

public void contextDestroyed(ServletContextEvent event)

Description copied from interface: javax.servlet.ServletContextListener

Receives notification that the ServletContext is about to be shut down.

All servlets and filters will have been destroyed before any ServletContextListeners are notified of context destruction.

Specified by:

contextDestroyed in interface ServletContextListener

Parameters:

event - the ServletContextEvent containing the ServletContext that is being destroyed