How to force JMapViewer to load tiles from local files (cache) only or stored .osm file

I am using JMapViewer in Java Swing desktop application. To load and render OSM tiles internet connection is required. But I do not want the map I am using to be updated at all. Even more - I want to draw my own map with JOSM, save it in a local .osm file and use it (only) in my application. Is it possible? How can I do it? Thank you very much in advance.