java.net.UnknownHostException: Invalid hostname for server: local

I was having the same issue on my mac. I found the issue when I pinged my $HOSTNAME from terminal and it returned ping: cannot resolve myHostName: Unknown host.

To resolve:

1. Do echo $HOSTNAME on your terminal.

2. Whatever hostname it shows (lets say myHostName), try to ping it : ping myHostName. If it returns ping: cannot resolve myHostName: Unknown host then add an entry into your /etc/hosts file.

3. For that edit /etc/hosts file and add following:

   127.0.0.1 myHostName