Failed on relative paths

[sshikov]

When 2nd parameter for Main specified as relative name like out.txt, failed on substring here:

public OutputStream getOutputStream(final String filename) {
try {
final String path = filename.substring(0, filename.lastIndexOf(File.separatorChar));
final File dir = new File(path);
dir.mkdirs();

Should be something like new File(filename).getParentFile().mkdirs() or so.