OpenID consumer for JAVA GAE

Is there any OpenID implementation I开发者_运维技巧 could use in my GAE (Google App Engine) Project?

I think it is now supported by GAE sdk http://code.google.com/intl/nl-NL/appengine/articles/openid.html

One option is to use RPX which allows your application to accept OpenID from multiple sources without you having to do the hard work.

I have used it for my GAE app, even jusing GWT and it works well.

rpxnow.com

I can tell you that openid4java does not work with GAE since GAE excludes certain redirects. See: link text

Combine Spring security, OpenID4java and Step2. It seems to work. I haven't deployed it to appspot, but it worked on Eclipse + GAE.