TestIPv6NIOServerSocketChannel (Hortonworks Data Platform Apache HBase Java API Reference)

```
public class TestIPv6NIOServerSocketChannel
extends Object
```
This tests whether ServerSocketChannel works over ipv6, which Zookeeper depends on. On Windows Oracle JDK 6, creating a ServerSocketChannel throws java.net.SocketException: Address family not supported by protocol family exception. It is a known JVM bug, seems to be only resolved for JDK7: http://bugs.sun.com/view_bug.do?bug_id=6230761 For this test, we check that whether we are effected by this bug, and if so the test ensures that we are running with java.net.preferIPv4Stack=true, so that ZK will not fail to bind to ipv6 address using ClientCnxnSocketNIO.

Constructors
Constructor and Description
`TestIPv6NIOServerSocketChannel()`

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`ensurePreferIPv4()` Checks whether we are running with java.net.preferIPv4Stack=true
`static void`	`main(String[] args)`
`void`	`testServerSocket()` Checks whether we are effected by the JDK issue on windows, and if so ensures that we are running with preferIPv4Stack=true.
`void`	`testServerSocketFromLocalhostResolution()` Tests whether every InetAddress we obtain by resolving can open a ServerSocketChannel.

Class TestIPv6NIOServerSocketChannel