Create Folder If It Does Not Exist In The Google Drive

Answer :

Files.List request = service.files().list().setQ(
       "mimeType='application/vnd.google-apps.folder' and trashed=false");
FileList files = request.execute();

You could now go through all folders in "files" and check if any of the folders have the searched title.

Don't forget to loop through all pages with:

request.setPageToken(files.getNextPageToken());

Edit:

Maybe you could have a look at this site. You can add the title in your search criteria instead so you do not have to retrieve all the folders.