spring security 配置看不明,求助!!!

security.xml配置文件如下:
<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/security" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:beans="http://www.springframework.org/schema/beans"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-2.0.1.xsd">

<http auto-config="true" lowercase-comparisons="false">
<!--intercept-url pattern="/images/*" filters="none"/>
<intercept-url pattern="/styles/*" filters="none"/>
<intercept-url pattern="/scripts/*" filters="none"/-->
<intercept-url pattern="/admin/*" access="ROLE_ADMIN"/>
<intercept-url pattern="/passwordHint.html*" access="ROLE_ANONYMOUS,ROLE_ADMIN,ROLE_USER,ROLE_MANAGER"/>
<intercept-url pattern="/signup.html*" access="ROLE_ANONYMOUS,ROLE_ADMIN,ROLE_USER,ROLE_MANAGER"/>
<intercept-url pattern="/a4j.res/*.html*" access="ROLE_ANONYMOUS,ROLE_ADMIN,ROLE_USER,ROLE_MANAGER"/>
<intercept-url pattern="/bank*.html*" access="ROLE_ADMIN,ROLE_MANAGER"/>
<intercept-url pattern="/charge*.html*" access="ROLE_ADMIN,ROLE_MANAGER"/>
<!-- APF-737, OK to remove line below if you're not using JSF -->
<intercept-url pattern="/**/*.html*" access="ROLE_ADMIN,ROLE_USER,ROLE_MANAGER"/>
<form-login login-page="/login.jsp" authentication-failure-url="/login.jsp?error=true" login-processing-url="/j_security_check"/>
<remember-me user-service-ref="userDao" key="e37f4b31-0c45-11dd-bd0b-0800200c9a66"/>
</http>


<!--关键是这里看不明,spring是将form里的j_username和j_password传递给userDao吗???-->
<authentication-provider user-service-ref="userDao">
<password-encoder ref="passwordEncoder"/>
</authentication-provider>



<!-- Override the default password-encoder (SHA) by uncommenting the following and changing the class -->
<!-- <bean id="passwordEncoder" class="org.springframework.security.providers.encoding.ShaPasswordEncoder"/> -->


<global-method-security>
<protect-pointcut expression="execution(* *..service.UserManager.getUsers(..))" access="ROLE_ADMIN"/>
<protect-pointcut expression="execution(* *..service.UserManager.removeUser(..))" access="ROLE_ADMIN"/>
</global-method-security>
</beans:beans>
###########################################################################################################
<!--关键是这里看不明,spring是将form里的j_username和j_password传递给userDao吗???-->
<authentication-provider user-service-ref="userDao">
<password-encoder ref="passwordEncoder"/>
</authentication-provider>