OpenStreetMap - java library to handle offline map

I need to create an application that would run on a linux system. Basically, I want to achieve something like Google Maps, but with much less functionality. The application needs to be able to do the followings:

open and display offline maps, as there won't be any internet connection
there will be a static route, like a railway, that has to be displayed, it won't change
there will be one dynamically changing point, it should be updated

I never really developed this kind of an application, I only used Google Maps for android v2, which is quite straight forward, so I wouldn't have any problem, but without internet connection, this isn't an option. So here are my questions:

I downloaded the map in .osm format, which I need. If I understand correctly, I need to pre-render this files, using something like Mapnik. Is this approach correct? If yes, how can I use Mapnik for this rendering? If not, what do you recommend?
Let's say I am done with the rendering part. If I understand correctly, now I should use something like JMapViewer. I should just import the .jar into my project, then this api would provide a mapview, and with some coding, I can use the api to display my already rendered, offline maps. Is this correct?

Also, if you can suggest anything, that would help me, I would be grateful.

Thanks in advance, cheers

basically you have to follow the following steps:

setup a mapnik server load the *.osm file and prerender all tiles you need. (store them in some sort of zip archive as the become pretty big in higher zoomlevels, you also fill unused space in the sectors on your harddrive [tar.gz])
write your own class extending from AbstractOsmTileSource to link to the stored data
write your own class implementing the TileLoader interface to load required tiles from inside the archive
create instance of JMapViewer and set prev defined TileLoader and TileSource
add railway as MapPolygon
add current position as MapMarker