If your server is running Windows try this:
ControlPanel > System Security > Windows Firewall > Advance Settings > inboundRules > New Rule
Add port 8080 and let us know if that solves your question.
If you are running Linux...
First, you should disable selinux, edit file /etc/sysconfig/selinux so it looks like this:
- SELINUX=disabledSELINUXTYPE=targeted
Save file and restart system.
Then …