our web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>
            /WEB-INF/config/security-config.xml
        </param-value>
    </context-param>

    <!-- Enables Spring Security -->
    <filter>
        <filter-name>springSecurityFilterChain</filter-name>
        <filter-class>
            org.springframework.web.filter.DelegatingFilterProxy
        </filter-class>
    </filter>

    <filter-mapping>
        <filter-name>springSecurityFilterChain</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <listener>
        <listener-class>
            org.springframework.web.context.ContextLoaderListener
        </listener-class>
    </listener>

    <servlet>
        <servlet-name>app</servlet-name>
        <servlet-class>main.servlet.name</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>default</servlet-name>
        <url-pattern>*.css</url-pattern>
        <url-pattern>*.js</url-pattern>
        <url-pattern>*.png</url-pattern>
        <url-pattern>*.jpg</url-pattern>
        <url-pattern>*.gif</url-pattern>
        <url-pattern>*.ico</url-pattern>
        <url-pattern>*.swf</url-pattern>
    </servlet-mapping>
    <servlet-mapping>
        <servlet-name>app</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>