Simultaneous authentication and authorization for a group of spring-web-based applications thru frontend proxy

Lets assume we have N java web applications on the same server. In case we need shared sessions on them, we can do next steps:

• let fronted rewrite all requested URL like /requestedApp/requestedPath/... to /entryApp/requestedApp/requestedPath/...
• let entryApp create session wrapper
• let entryApp internally forward request to requestedApp
• done.

It doesn't matter what kind of applications we have - all of them use shared sessions (and information in them) now.

• first and the most significant: classloaders. You have to deploy all the Spring stuff as the shared libraries, otherwise ClassCastExceptions will be pulled.
• frontend (to do rewrites needed). Example configuration for nginx included here: https://github.com/Lsync/lsync-tests-spring-sharedsess-proxy/tree/master/ConfigExamples/nginx
• servlet container (to let JSESSIONID have a path like "/" and not "/appName/"). Example for Tomcat included
• "dispatcher" tags should be added to each web.xml filter mapping (otherwise they won't do filters on forwarded requests). See an example of web.xml in the sample applications