A simple DNS server that gets a hostname from a client and returns the hostname's IP address.
Basically, this simplistic DNS server has as point of reference a text file called hosts.txt where each line has a hostname and its IP address separated with one space (initialized only with localhost):
When the client sends a UDP packet with a hostname, the server looks up hosts.txt and if it fails to find the address of the given hostname, it searches it on the internet with java.net.InetAddress.getByName() and puts the found address along with the hostname in hosts.txt. If the hostname doesn't seem to exist, it sends "-1" back to the client.
java DNS_Server <port_number (default: 8888)>java DNS_Server
Tied with sister project DNS-Client.
Tested on NetBeans 8.2.