package com.example;

public class Dog {
    private String breed;

    public Dog(String breed){
        this.breed=breed;
    }

    public String getBreed(){
        return breed;
    }
}

package com.example;

import javax.servlet.*;

public class MyServletContextList implements ServletContextListener {
    public void contextInitialized(ServletContextEvent event){
        ServletContext sc = event.getServletContext();
        String dogBreed = sc.getInitParameter("breed");
        Dog d = new Dog(dogBreed);
        sc.setAttribute("dog",d);
    }
    public void contextDestroyed(ServletContextEvent event){

    }
}


 class Dog {
    private String breed;

    public Dog(String breed){
        this.breed=breed;
    }

    public String getBreed(){
        return breed;
    }
}

<?xml version="1.0" encoding="ISO-8859-1" ?>
<web-app xmlns="http://java.sun.com/xml/ns/j2ee"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"
	version="2.4">
 <servlet>
     <servlet-name>ListenerTester</servlet-name>
     <servlet-class>com.example.ListenerTester</servlet-class>
 </servlet>
<servlet-mapping>
    <servlet-name>ListenerTester</servlet-name>
    <url-pattern>/Listener.do</url-pattern>
</servlet-mapping>
    
 <listener>
     <listener-class>com.example.MyServletContextList</listener-class>
 </listener>

 <context-param>
     <param-name>breed</param-name>
     <param-value>Great Dane</param-value>
 </context-param>
</web-app>