InetAddress.getLocalHost() slow to run (30+ seconds)

Question

With the following code:

try {   System.out.println(new Date());   InetAddress hostName = InetAddress.getLocalHost();   System.out.println(new Date()); } catch (UnknownHostException e) {   e.printStackTrace(); } 

I get this output:

Thu Oct 22 20:58:22 BST 2015 Thu Oct 22 20:58:52 BST 2015 

In other words 30 seconds to execute. Machine is 2015 Macbook Pro with Java 1.8.0_60.

Why does this take so long?

Answer 1

The issue can be solved by adding the following to /etc/hosts (assuming output of hostname command is my-macbook:

127.0.0.1   my-macbook ::1         my-macbook 

This returns the time to something more suitable (< 1 second)

Answer 2

This problem appears on MacOS Sierra using Java8, updates equals or bigger than 60 (jdk1.8.0_60.jdk, jdk1.8.0_77.jdk, etc).

The solution can be found here: https://github.com/thoeni/inetTester.

This is the content of my /etc/hosts file:

127.0.0.1   localhost mac.local ::1         localhost mac.local 

In my case, mac is my computer name.