spring-security怎么配置两个<http>对应两个登陆页？我这个为什么报错了

Question

 <http pattern="/admin/**" authentication-manager-ref="authmanager" >   
        <intercept-url pattern="/admin/login**" access="IS_AUTHENTICATED_ANONYMOUSLY" />
        <intercept-url pattern="/admin/**" access="ROLE_ADMIN" />  
        <form-login login-page="/admin/login.jsp" authentication-failure-url="/login_fail.jsp" default-target-url="/index.jsp"/>  
    </http>
    <http pattern="/front/**" authentication-manager-ref="authmanager">     
        <intercept-url pattern="/front/login**" access="IS_AUTHENTICATED_ANONYMOUSLY" />
        <intercept-url pattern="/front/**" access="ROLE_ADMIN" />  
        <form-login login-page="/front/login.jsp" authentication-failure-url="/login_fail.jsp" default-target-url="/index.jsp"/>  
    </http>

这样写了/j_spring_security_check会报404 那个，去掉pattern="/admin/**"就可以
但是不加啥pattern="/admin/**" 编译的时候会报一个两个url重复的错误。。。哎怎么办呢