private void add_yubikey_to_user(String publicId, String username, String filename) {
		try {
			File file = new File(filename);
			FileWriter writer = new FileWriter(file, true);
			writer.write("yk." + publicId + ".user = " + username
					+ System.getProperty("line.separator"));
			writer.close();
		} catch (IOException ex) {
			log.error("Failed appending entry to file {}", filename, ex);
		}
	}
private void add_yubikey_to_user(String publicId, String username, String filename) {
		try {
			File file = new File(filename);
			FileWriter writer = new FileWriter(file, true);
			writer.write("yk." + publicId + ".user = " + username
					+ System.getProperty("line.separator"));
			writer.close();
		} catch (IOException ex) {
			log.error("Failed appending entry to file {}", filename, ex);
		}
	}
private void add_yubikey_to_user ( String publicId , String username , String filename ) { try { File file = new File ( filename ) ; FileWriter writer = new FileWriter ( file , true ) ; writer . write ( "yk." + publicId + ".user = " + username + System . getProperty ( "line.separator" ) ) ; writer . close ( ) ; } catch ( IOException ex ) { log . error ( "Failed appending entry to file {}" , filename , ex ) ; } }
Stores an association between username and YubiKey publicId in filename.

@param publicId YubiKey public ID to associate with user
@param username username to associate with a YubiKey public ID
@param filename name of the file to store to
Stores an association between username and YubiKey publicId in filename .