Do you use a Vaadin application as portlet with e.g. Liferay and does your application create generic downloads (e.g. reports)?

If you want to download generic/dynamically created files from a portlet, you don't have too many options. You could use the FileDownloader extension or you could open a new window with the file resource. But both options are not perfect. The FileDownloader has to be connected to a clickable component e.g. a button and the new window won't be closed automatically (browser dependent). The FileDownloader is a good solution (see recommendations) but it triggers the download from the browser via user interaction. If you have dynamic UIs or if you can't use a FileDownloader because you need a more generic solution, then you could have a problem?

Our JVx Vaadin UI implementation is very dynamic and a developer doesn't use native vaadin components (until he needs to do). The FileDownloader didn't work for us because of UI abstraction. But we have a solution that might help you as well. Its comparable to FileDownloader but it's not user driven.

Simply use our extension with your UI:

The extension is not limited to UI but one Downloader per application is enough.

The source code is available in our repository.