404 Error on /spring_security_login Spring Security 3.2 after migrating from Tomcat 6 to Tomcat 7 - spring

Question

It's been now three days that I'm battling to make my application work again.
The pitch : I had an application using Spring Security 3.2 and running well on Tomcat 6.
I want to migrate all my apps on Tomcat 7, so that's why I'm trying that.
BUT : every time I access to the root of my app, I get a 404 error page, with /spring_security_login written in the URL.
For the /spring_security_login written, it seems partially legit, because Spring is set to create the login form on its own. But why the 404 error ?
On Tomcat 6, with the same web.xml and applicationContext-security, the site is running well.
Last but not least, my login is made through the Spring Security ldap provider, so it adds one more level of complexity...
Here is my web.xml :
<?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" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
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>MYAPP</display-name>
<!-- où se trouve la conf spring: -->
<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/applicationContext-security.xml</param-value>
</context-param>
<listener>
<listener-class>
org.springframework.web.context.ContextLoaderListener
</listener-class>
</listener>
<listener>
<listener-class>
org.springframework.security.web.session.HttpSessionEventPublisher
</listener-class>
</listener>
<filter>
<filter-name>springSecurityFilterChain</filter-name>
<filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
</filter>
<!-- Reads request input using UTF-8 encoding -->
<filter>
<filter-name>characterEncodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<init-param>
<param-name>encoding</param-name>
<param-value>UTF-8</param-value>
</init-param>
<init-param>
<param-name>forceEncoding</param-name>
<param-value>true</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>characterEncodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<filter-mapping>
<filter-name>springSecurityFilterChain</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!-- configuration spring -->
<servlet>
<servlet-name>myapp-webapp</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<load-on-startup>3</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>myapp-webapp</servlet-name>
<url-pattern>*.do</url-pattern>
<url-pattern>/remoting/*</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>default</servlet-name>
<url-pattern>*.png</url-pattern>
<url-pattern>*.js</url-pattern>
<url-pattern>*.css</url-pattern>
<url-pattern>*.gif</url-pattern>
</servlet-mapping>
<resource-ref>
<description>DB Connection</description>
<res-ref-name>jdbc/myapp_database</res-ref-name>
<res-type>javax.sql.DataSource</res-type>
<res-auth>Container</res-auth>
</resource-ref>
</web-app>
And my applicationContext-security.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:s="http://www.springframework.org/schema/security"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.2.xsd">
<s:global-method-security secured-annotations="disabled">
</s:global-method-security>
<s:http pattern="/styles/**" security="none"/>
<s:http pattern="/js/**" security="none"/>
<s:http pattern="/img/**" security="none"/>
<s:http pattern="/html/**" security="none"/>
<s:http pattern="/remoting/**" security="none"/>
<!-- config ldap activee use-expressions="true" -->
<s:http auto-config="true" create-session="always" access-decision-manager-ref="accessDecisionManager">
<s:intercept-url pattern="/cancelPreviousAction.do" access="P_MYAPP_RW" />
<s:intercept-url pattern="/**" access="P_MYAPP_RO" />
<s:session-management>
<s:concurrency-control max-sessions="1" />
</s:session-management>
<s:form-login />
<s:logout/>
</s:http>
<s:authentication-manager>
<s:authentication-provider ref="ldapProvider"></s:authentication-provider>
</s:authentication-manager>
<bean id="contextSource"
class="org.springframework.security.ldap.DefaultSpringSecurityContextSource">
<constructor-arg value="..." />
<property name="userDn" value="..." />
<property name="password" value="..." />
</bean>
<bean id="ldapProvider" class="org.springframework.security.ldap.authentication.LdapAuthenticationProvider">
<constructor-arg>
<bean class="org.springframework.security.ldap.authentication.BindAuthenticator">
<constructor-arg ref="contextSource" />
<property name="userSearch">
<bean id="userSearch"
class="org.springframework.security.ldap.search.FilterBasedLdapUserSearch">
<constructor-arg index="0" value="..." />
<constructor-arg index="1" value="..." />
<constructor-arg index="2" ref="..." />
</bean>
</property>
</bean>
</constructor-arg>
<constructor-arg>
<bean class="org.springframework.security.ldap.userdetails.DefaultLdapAuthoritiesPopulator">
<constructor-arg ref="contextSource" />
<constructor-arg value="..." />
<property name="rolePrefix" value="" />
<property name="searchSubtree" value="true" />
<property name="convertToUpperCase" value="false" />
</bean>
</constructor-arg>
</bean>
<bean id="accessDecisionManager" class="org.springframework.security.access.vote.AffirmativeBased">
<property name="allowIfAllAbstainDecisions" value="false" />
<property name="decisionVoters">
<bean class="org.springframework.security.access.vote.RoleVoter">
<property name="rolePrefix" value=""/>
</bean>
</property>
</bean>
</beans>
Anybody has a clue ?
I though one time that it might be my Tomcat conf that would be the cause, but now when I call the root url of my app, the /spring_security_login appends itself in the url, so I think the redirection inside Spring Seuciryt works well...
NB : When I remove the spring Security filter from the web.xml file, the app works well (except the login/security part needless to say).
Thanks in advance !

Answer 1

In fact the problem was that under Tomcat 6, I had overrided the definition of the default servlet.
After having searched long times and long times, I tried commenting the default servlet definition... and everything worked.
So in web.xml, comment the following lines to have the same :
<!--
<servlet-mapping>
<servlet-name>default</servlet-name>
<url-pattern>*.png</url-pattern>
<url-pattern>*.js</url-pattern>
<url-pattern>*.css</url-pattern>
<url-pattern>*.gif</url-pattern>
</servlet-mapping> -->
And it fixed everything.