RFR: 8244958: preferIPv4Stack and preferIPv6Addresses do not affect addresses returned by HostsFileNameService

[Alan Bateman]

On 22/05/2020 16:45, Aleks Efimov wrote:
> Hi,
>
> The "java.net.preferIPv4Stack" and "java.net.preferIPv6Addresses" 
> system properties do not affect the addresses and their order, 
> returned by the HostsFileNameService provider that can be created by 
> specifying "jdk.net.hosts.file" system property.
> The following fix analyses the system properties and re-orders/filters 
> the returned IP addresses, if needed. Plus, small clean-up changes:
> http://cr.openjdk.java.net/~aefimov/8244958/00
The approach looks okay but I agree with Daniel on consistent naming and 
cleanup.

Another one to look is arrangeAddresses/appendAddresses as it's 
surprising to mutate inet4Addresses or inet6Addresses with addresses of 
the other type. It would be much cleaner to return a List (inetAddress 
or a new List), then invoke toArray on the result and this will avoid 
calling toArray in 3 places. If you using List in the signatories then 
it will also be a lot cleaned as the caller should not need to provide a 
specific type of List.

Minor nit in the test but PREFER4_SP_VALUE and PREFER6_SP_VALUE can be 
renamed to make the usages in the test easier to read. Also good to add 
"_LIST" to IPV4_THEN_IPV6 to make it clearer at the use sites that they 
are dealing with Lists. I think getExpectedAddressesArray would be a bit 
clear if you assigned the result of the switch expression to a variable, 
then return list.toArray(String::new).

-Alan