RFR 8169115, java/net/InetAddress/ptr/lookup.sh failed intermittently

[Felix Yang]

Hi,

    please review the following patch. It generally coverts codes from 
shell to plain java.

Bug:

     https://bugs.openjdk.java.net/browse/JDK-8169115

Webrev:

     http://cr.openjdk.java.net/~xiaofeya/8169115/webrev.00/

Thanks,

Felix