Spring provides some proprietary ways to change the display locale. This documentation will describe how to change it via an URL query string parameter and how to persist it with a cookie. This method may or may not work in any particular Spring version without changes.
The configurations below are intended to be placed in conf/mvc-beans.xml, whch you would need to create (you can copy one of the other native Spring beans files as a template to start from).
Locale cookie persistance
Enabling locale change persistance via a cookie is done by defining the CookieLocaleResolver bean and optionally changing it's defaults: