Login with Spring security using Ajax

I am trying to work on Ajax based login system using Spring Security and it was working fine, till I got with another requirement where I need to configure authentication-success-handler, so as I can do some post processing once user is authenticated by Spring security.

Earlier I was not using <form-login/> for showing Login page.My Login section is a drop down and part of header section which is common for entire application.

This is how I am trying to configure Spring security

<http pattern="/customer/**" auto-config="true" use-expressions="true" authentication-manager-ref="customerAuthenticationManager">
<!--<http pattern="/customer/**" auto-config="true" use-expressions="true">-->
<intercept-url pattern="/customer/logon.html*" access="permitAll" />
<intercept-url pattern="/customer/denied.html" access="permitAll"/>
<intercept-url pattern="/customer" access="hasRole('AUTH_CUSTOMER')" />
<intercept-url pattern="/customer/" access="hasRole('AUTH_CUSTOMER')" />
<intercept-url pattern="/customer/*.html" access="hasRole('AUTH_CUSTOMER')" />
<intercept-url pattern="/customer/*/*.html" access="hasRole('AUTH_CUSTOMER')" />

<form-login login-processing-url="/customer/logon.html" login-page="/shop/home.html" 
authentication-success-handler-ref="webshopAuthenticationSuccessHandler" />

<logout invalidate-session="true" 
   logout-success-url="/customer/home.html" 
    logout-url="/customer/j_spring_security_logout" />
 <access-denied-handler error-page="/customer/denied.html"/>
    </http>

With these configuration, when ever I am clicking on login button with correct credentials, i am getting HTTP 302 error

http://localhost:8080/shop/customer/logon.html 302 found

Not sure what exactly I am doing wrong?

<form id="login" method="post" accept-charset="UTF-8">
    <input id="userName" type="text" name="userName" size="30" />
    <button type="submit" class="btn">Login</button>
</form>

Ajax Code

 var data = $(this).serializeObject();
  $.ajax({
  'type': 'POST',
  'url': "<c:url value="/customer/logon.html"/>",
   'contentType': 'application/json',
    'data': JSON.stringify(data),
     'dataType': 'json',
....
}}:

Login Section

 Authentication authenticationToken = new UsernamePasswordAuthenticationToken(customer.getUserName(), customer.getPassword());
   try {
       Authentication authentication = customerAuthenticationManager.authenticate(authenticationToken);
        SecurityContextHolder.getContext().setAuthentication(authentication);
        resp.setStatus(AjaxResponse.RESPONSE_STATUS_SUCCESS);
           } catch (AuthenticationException ex) {

            resp.setStatus(AjaxResponse.RESPONSE_STATUS_FAIURE);
   }

Any inputs? With all my efforts, I am still getting 302 and with above configuration, even my logon.html controller is not getting called.

My main issue is when I am enabling Spring security using

<form-login login-processing-url="/customer/logon.html" login-page="/shop/home.html" 
    authentication-success-handler-ref="webshopAuthenticationSuccessHandler" />

I am getting 302 from logon.html and even logon.html Controller is not being triggered (placed debugger on it)