Rest Spring Security-自定义JSON消息，而不是显示登录页面

我希望得到您对以下内容的宝贵反馈。 我一直在处理Spring安全性。我知道，当我通过表单登录登录时，登录处理url将被触发，页面将重定向到spring security登录

但是，当我还没有登录到我的应用程序，但试图通过REST访问任何API URL时，是否可以抛出自定义JSON消息。非常感谢你的帮助

我使用ExtJS进行UI登录，使用Spring作为RESTful服务

想集成这两个视图Spring登录视图和我的自定义ExtJS登录视图吗

<security:http  authentication-manager-ref="authenticationManager"  use-expressions='true' >
        <security:form-login login-processing-url="/login" always-use-default-target="true" 
                             default-target-url="/user/authen" username-parameter="uid" password-parameter="password"
                             authentication-failure-handler-ref="authenticationFailureHandler"   />


        <security:intercept-url pattern="/login" access="permitAll" />
        <security:intercept-url pattern="/**" access="isAuthenticated()" />
        <security:intercept-url pattern="/denied" access="permitAll" />
        <security:access-denied-handler  error-page="/login/accessDenied"/>
        <security:logout logout-url="/logout" invalidate-session="true" />
        <security:http-basic/>
    </security:http>
    <bean id="authenticationFailureHandler"
          class="org.springframework.security.web.authentication.ExceptionMappingAuthenticationFailureHandler">
        <property name="exceptionMappings">
            <props>
                <prop key="org.springframework.security.authentication.BadCredentialsException">/login/badCredentials</prop>
                <prop key="org.springframework.security.authentication.CredentialsExpiredException">/login/credentialsExpired</prop>
                <prop key="org.springframework.security.authentication.LockedException">/login/accountLocked</prop>
                <prop key="org.springframework.security.authentication.DisabledException">/login/accountDisabled</prop>
                <prop key="org.springframework.security.authentication.AccessDeniedException">/login/accessDenied</prop>
            </props>
        </property>
    </bean>

R.R.维涅斯瓦兰