enum ChangeSource {
    INTERNAL, // indicates a change made by this application
    EXTERNAL, // indicates an external change
}
// create LiveDirs to watch a directory
LiveDirs<ChangeSource> liveDirs = new LiveDirs<>(EXTERNAL);
Path dir = Paths.get("/path/to/watched/directory/");
liveDirs.addTopLevelDirectory(dir);
// use LiveDirs as a TreeView model
TreeView<Path> treeView = new TreeView<>(liveDirs.model().getRoot());
treeView.setShowRoot(false);
// handle external changes
liveDirs.model().modifications().subscribe(m -> {
    if(m.getInitiator() == EXTERNAL) {
        // handle external modification, e.g. reload the modified file
        reload(m.getPath());
    } else {
        // modification done by this application, no extra action needed
    }
});
// Use LiveDirs's I/O facility to write to the filesystem,
// in order to be able to distinguish between internal and external changes.
Path file = dir.resolve("some/file.txt");
liveDirs.io().saveUTF8File(file, "Hello text file!", INTERNAL);
// clean up
liveDirs.dispose();