使用spring security时遇到一个问题，有大量的ajax post是需要登录控制的，但是默认的spring-security机制导致post结果返回的是登录页。

?

现在要解决几个问题：

1，ajax post如果需要登录的话，返回需要登录的json消息，前端可以继续处理

2，新建一套ajax login的页面流转，但是不能和原有的login过程冲突，因为其他的非ajax请求还是需要用正常的login。

?

?spring security配置如下:

<?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:security="http://www.springframework.org/schema/security"
       xsi:schemaLocation="
           http://www.springframework.org/schema/beans
           http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
           http://www.springframework.org/schema/security
           http://www.springframework.org/schema/security/spring-security-3.0.xsd">

	<!-- Configure Spring Security -->
	<!--
	<security:http auto-config="true">
		<security:form-login login-page="/login" login-processing-url="/loginProcess" 
			default-target-url="/" authentication-failure-url="/login?login_error=1" />
		<security:logout logout-url="/logout" logout-success-url="/logoutSuccess" />
		<security:remember-me key="bookingtest" />
	</security:http>
	-->
	<security:http auto-config="false" entry-point-ref="jilujiaAuthenticationEntryPoint">
	    <!-- 登录过滤器 -->
             <security:custom-filter before="FORM_LOGIN_FILTER" ref="loginFilter"/>
             <!-- ajax登录过滤器 -->
             <security:custom-filter position="FORM_LOGIN_FILTER" ref="ajaxLoginFilter"/>
             <!-- 只cache get,避免ajax post 被cache -->
             <security:request-cache ref="httpSessionRequestCache"/>
             <!-- 注销过滤器 -->
             <security:logout logout-url="/logout" logout-success-url="/logoutSuccess" />
             <!-- remember me -->
             <security:remember-me key="bookingtest" />
	</security:http>
	
	<bean id="jilujiaAuthenticationEntryPoint" class="com.jilujia.framework.security.JilujiaAuthenticationEntryPoint">
	    <property name="loginFormUrl" value="/login" />
	</bean>
	
	<bean id="httpSessionRequestCache" class="org.springframework.security.web.savedrequest.HttpSessionRequestCache">
	    <property name="justUseSavedRequestOnGet" value="true" />
	</bean>
	
	<!-- 验证普通用户 -->  
	<bean id="loginFilter" class="org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter">
	    <property name="authenticationManager" ref="authenticationManager"/>
	    <property name="authenticationFailureHandler" ref="failureHandler"/>
	    <property name="authenticationSuccessHandler" ref="successHandler"/>
	    <property name="filterProcessesUrl" value="/loginProcess"/>
	</bean>

	<bean id="failureHandler" class="org.springframework.security.web.authentication.SimpleUrlAuthenticationFailureHandler">
	    <property name="defaultFailureUrl" value="/login?login_error=1" />
	</bean>

	<bean id="successHandler" class="org.springframework.security.web.authentication.SavedRequestAwareAuthenticationSuccessHandler">
	    <property name="alwaysUseDefaultTargetUrl" value="false"/>
	    <property name="defaultTargetUrl" value="/"/>
	</bean>
	<!-- 验证ajax请求--> 
	<bean id="ajaxLoginFilter" class="org.springframework.security.web.authentication.UsernamePasswordAuthenticationFilter">
	    <property name="authenticationManager" ref="authenticationManager"/>
	    <property name="authenticationFailureHandler" ref="ajaxFailureHandler"/>
	    <property name="authenticationSuccessHandler" ref="ajaxSuccessHandler"/>
	    <property name="filterProcessesUrl" value="/ajaxLoginProcess"/>
	</bean>
	
	<bean id="ajaxFailureHandler" class="com.jilujia.fra