Class webAppRootListener

java.lang.Object
org.springframework.web.util.webAppRootListener
All Implemented Interfaces:
jakarta.servlet.ServletContextListener, EventListener
public class webAppRootListener extends Object implements jakarta.servlet.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, for example, 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 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:

  • Constructor Details

    • webAppRootListener

      public webAppRootListener()

  • Method Details

    • contextInitialized

      public void contextInitialized(jakarta.servlet.ServletContextEvent event)
      Specified by:
      contextInitialized in interface jakarta.servlet.ServletContextListener

    • contextDestroyed

      public void contextDestroyed(jakarta.servlet.ServletContextEvent event)
      Specified by:
      contextDestroyed in interface jakarta.servlet.ServletContextListener