Spring security + LocaleResolver

Question

i need to change locale settings after successful Authentication.

LocaleResolver:

    <bean id="localeChangeInterceptor"
    class="org.springframework.web.servlet.i18n.LocaleChangeInterceptor">
    <property name="paramName" value="lng" />
    </bean>

   <bean id="localeResolver"
     class="web.MyLocaleResolver">
   </bean>

---

   public class MyLocaleResolver extends AbstractLocaleResolver {

   private Locale default = Locale.ENGLISH;

       @Override
       public Locale resolveLocale(HttpServletRequest hsr) {
           return this.default;
       }

       @Override
       public void setLocale(HttpServletRequest hsr, HttpServletResponse hsr1,         Locale default) {
           this.default = default;
       }

   }

Security:

     <form-login login-page="/login" 
          authentication-success-handler- ref="MySuccessAuthHandler"/>
     <beans:bean id="MySuccessAuthHandler" class="web.MySuccessfulAuthenticationHandler">
         <beans:property name="defaultTargetUrl" value="/index.htm"></beans:property>
     </beans:bean>

---

public class MySuccessfulAuthenticationHandler extends  SavedRequestAwareAuthenticationSuccessHandler  {
  @Override
  public void onAuthenticationSuccess(HttpServletRequest request, HttpServletResponse response,
        Authentication authentication) throws ServletException, IOException {

        super.onAuthenticationSuccess(request, response, authentication);
        RequestContextUtils.getLocaleResolver(request).setLocale(request, response, Locale.ENGLISH);
   }

}

When i try to set locale by RequestContextUtils i get NullPointer Exception.

Answer 1

LocaleResolver is exposed in request context by DispatcherServlet, whereas AuthenticationSuccessHandler is fired before request enters DispatcherServlet (actually, request that fired SavedRequestAwareAuthenticationSuccessHandler never enters DispatcherServlet, because this handler performs a redirect).

Thus, you cannot access LocaleResolver via RequestContextUtils in this case. You can try to inject LocaleResolver into your AuthenticationSuccessHandler explicitly, for example, with autowiring.