Pasted

    public static File revert(File current, File original) throws IOException {
        // do nothing if current and original path is exactly the same
        if (current.equals(original)) {
            return original;
        }
 
        // reverse move
        if (current.exists() && !original.exists()) {
            return moveRename(current, original);
        }
 
        BasicFileAttributes currentAttr = Files.readAttributes(current.toPath(), BasicFileAttributes.class, LinkOption.NOFOLLOW_LINKS);
        BasicFileAttributes originalAttr = Files.readAttributes(original.toPath(), BasicFileAttributes.class, LinkOption.NOFOLLOW_LINKS);
 
        // reverse symlink
        if (currentAttr.isSymbolicLink() && !originalAttr.isSymbolicLink()) {
            trash(current);
            return original;
        }
 
        // reverse keeplink
        if (!currentAttr.isSymbolicLink() && originalAttr.isSymbolicLink()) {
            trash(original);
            return moveRename(current, original);
        }
 
        // reverse copy / hardlink
        if (currentAttr.isRegularFile() && originalAttr.isRegularFile()) {
            trash(current);
            return original;
        }
 
        // reverse folder copy
        if (currentAttr.isDirectory() && originalAttr.isDirectory()) {
            trash(original);
            return moveRename(current, original);
        }
 
        throw new IllegalStateException(String.format("Cannot revert file: %s => %s", current, original));
    }