Thread: in FTP check if folder exist, if not create the file. without using FTPClient Class only URL`S Class

this is part of my code.

* folder name - folder on my ftp server already exist

 
			URL url3 = new URL("ftp://username:pass@host+folder name" + imageName + ".jpg");
			URLConnection con3 = url3.openConnection();
			ObjectOutputStream out3 = new ObjectOutputStream(con3.getOutputStream());
			ImageIO.write(image, "jpg", out3);
			out3.flush();
			out3.close();
			//end #6

i have for each client, serial.
i want to check for client that try to connected to ftp if foldernamed on is serial exist if not (first connection) to create the folder.

i know thats can be done with FTPClient, but i think its not so hard without FTPClient (because i already read and write files).
i just dont know how.

please give very simple solution

edit: another question, i try to delete file from my drive with file.delete() not working...
and i can delete file from ftp without FTPClient ? thank you