[CentOS] How to set hostname and domainnmae in CentOS 7?

We can permanently set hostname using  hostnamectl set-hostname. How can we
permanently set *domain name* in CentOS 7?
I found an article
<http://unix.stackexchange.com/questions/239920/how-to-set-the-fully-qualified-hostname-on-centos-7-0>
that recommended setting FQDN using hostnamectl. Is that the right way to
set hostname and domainname at the same time using *hostnamectl
set-hostname* command?

 Running *hostnamectl set-hostname* will set the hostname in* /etc/hostname*
but it doesn't change */etc/hosts*. What's the proper way of adding
hostname and FQDN to */etc/hosts *in CentOS 7?

Thanks,

Joe