mac系统InetAddress.getLocalHost().getHostAddress() 很慢

1. 就是把本机的hostname 添加到 hosts 中，例如: 

127.0.0.1 localhost
127.0.0.1 loulldeMacBook-Pro.local
255.255.255.255 broadcasthost
::1 localhost
::1 loulldeMacBook-Pro.local

2. 执行  scutil --set HostName "localhost"

大致原因，获取本机地址，走到了DNS解析，DNS递归解析不到本机域名，耗时5s左右