The ServletContextListener will start running before the web application has already started. This is ideal for logging or initiated responses

In this example, you will see a custom listener class by implementing ServletContextListener, which is executed before web application is started.

package com.iam.idl.client.servlet;

import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

/**
 * Servlet implementation class BannerAppWebListener
 */
public class BannerAppWebListener implements ServletContextListener {

	@Override
	public void contextDestroyed(ServletContextEvent arg0) {
		// TODO Auto-generated method stub
		
	}

	@Override
	public void contextInitialized(ServletContextEvent event) {
		System.out.println("------- ServletContextListener started ---------");
		//initalizeLog4JManager(event);
	}

}

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>BannerConsumerDEV</display-name>
  
  <!--  -->
  <listener>
    <listener-class>com.iam.idl.client.servlet.BannerAppWebListener</listener-class>
  </listener>
  
  <!--  -->
  <servlet>
    <description></description>
    <display-name>BannerAppWebListener</display-name>
    <servlet-name>BannerAppWebListener</servlet-name>
    <servlet-class>com.iam.idl.client.servlet.BannerAppWebListener</servlet-class>
  </servlet>
 
  <servlet-mapping>
    <servlet-name>BannerAppWebListener</servlet-name>
    <url-pattern>/BannerAppWebListener</url-pattern>
  </servlet-mapping>
  
  <context-param>
		<param-name>contextConfigLocation</param-name>
		<param-value>/WEB-INF/applicationContext.xml,/WEB-INF/spring-ws-servlet.xml</param-value>
	</context-param>
</web-app>

Startup weblogic and run application, then check the logs or within the WLS initiated terminal window

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