A couple of false assumptions here.
First, one of the primary uses of Flash is the ability to import external data. I'm not sure what you need for "interactive graphics" but let's take a slide show, or even a video player, for example.
A Flash slide show/video player consists of three major components: the Flash object itself, a directory where the graphics/video are stored, and a plain text XML file that contains various data about the slide show or video. Some examples would be the graphic file name, a caption, and maybe descriptive text.
When the Flash loads, it reads in the XML file, obtains the information needed for the video player/slide show - which can vary in length - and executes accordingly. So if built properly, you only need to upload files to the proper location and learn how to edit the XML file. You would never need to edit the Flash in this scenario, hence, you would never need Flash.
A caveat: you might need to encode standard video formats into .flv, or resize images correctly for a slide show, but a good programmer can even solve this without you having to do it manually. Using perl or PHP, they could add programming that auto sizes the images or encodes the video for you on upload. PM for a working example, we aren't allowed to post URL's here.
Second, if you *really* need or want to work with Flash directly, there is an open source solution that many people use called Swish. I've never used it because I have CS3, but the comments here seem very positive.
Overall, if you were looking at Java, implementing the same or a similar solution in Java would present as many or more difficulties as a Flash approach, it's a bit more difficult to learn.