Desktop & mobile web application with offline handling

I am evaluating different approaches to building a web based application which handles offline disconnection gracefully. The intention is to create a desktop/tablet UI and a separate mobile UI for the app, backend functionality would be implemented in Java. In principle, the components are mostly there; HTML5 offline seems to have wide support and works well while W开发者_如何学Pythoneb SQL has enough support (Chrome, Opera, iPhone & Android) that we could work with it for offline storage.

As regards creating the UI, it would be nice to use some of the nice JSF libraries out there (Primefaces looks quite nice for example although I've never used it in production). So far, I can't think of any way (and I can't see anything mentioned) of using either HTML5 offline or web SQL in a JSF app. Has this been tried? Is there any methodology/framework that might help here?

I'm also not averse to using client side frameworks. I was very impressed by Dojo for example but then found that it didn't render well on Android with webkit so that ruled it out of use for the tablet scenario. I can probably make jQuery work but I find it to be very fragmented (for example, getting an accordion to handle resizing inside a layout frame just put me off). Finally, I looked at GWT; I wasn't keen on the complexity of getting offline to work and the support for web sql seemed to be a work in progress (no slight intended to the developers, it just seemed to be at an early stage).

So, given the requirement for a web app that runs on desktop/tablet (android) and also on mobile (Android & iPhone) and which handles offline, how would you approach things?

Thanks, Phil