JavaWeb-ServletContextListener

ServletContextListener：

1) what: listening ServletContext object is created or destroyed Servlet listener

2）how：

　　> Create a class that implements ServletContextListener, and wherein the method implements two

　　public class HelloServletContextListener implements ServletContextListener

　　> Configuration Listener in the web.xml file

  <listener>
    <listener-class>listener.HelloListener</listener-class>
  </listener>

 

 3) why: ServletContextListener The Listener is the most commonly used, may be initializing operation of the current web application resources in the current web application is loaded: creating a database connection pool, creating a Spring IOC container, reads the current WEB application initialization parameters. . .　

 

4) API:

　　

   // ServletContext object is created (ie, the current WEB application is loaded) when, Servlet container calls this method. 
　　@Override 
    public void the contextInitialized (ServletContextEvent SCE) { 
       
    } 　　// ServletContext before an object is destroyed (i.e., the current WEB application is uninstalled) when, Servlet container calls the method 
    @Override 
    public void the contextDestroyed (ServletContextEvent SCE) { 
    } 　　　ServletContextEvent in : getServletContext () Gets ServletContext



        

 

　　

ServletRequestListener & HttpSessionListener 

1) and similar ServletContextListener