If you want to render a single frame with font and image definitions then that is not too difficult. Rendering images is quite straightforward - simply convert the image data to a BufferedImage and rendering to a Graphics2D object. For font definitions you will have to convert the glyph definitions to shapes and then scale and render the shapes on the Graphics2D.
If the frame is sufficiently complex then you will be, in effect, writing a Flash Player in Java. So you can see that this is a non-trivial problem - otherwise it would have been done already.
What I would suggest is to take a simple movie which moves a shape then try and render that in Java. That should give you a good start at addressing the problem and identifying the issues and from there it should simple be a matter of adding more features
The better solution might simple yo use one of the many programs that uses Adobe's OCX plugin and simply convert the movie to an image - these are all Windows only solutions however.
Sorry for the late reply.