MS SharePoint and Java Dev

Hello,

I was wondering if anyone knows about or has used Java
web/client-server functionality with MS SharePoint. For instance,
building portals using JSP's and Servlets within/managed by SharePoint.
Most of the articles I read about SharePoint caters to the .NET
infrastructure such as using C#, ASP.NET, and VB.NET. I would like to
leverage SharePoint's enterprise management ability with our Java
developed web/server portals. Any help would be greatly appreciated!

Thanks,
Chuck