Android API-23: InetAddressUtils replacement

To use this library in SDK 23 add following line in project's build.gradle file:

useLibrary 'org.apache.http.legacy'

Like I interprete from the comments you can replace that function with this comparison:

inetAddress instanceof Inet4Address

so your code would end in:

if(!inetAddress.isLoopbackAddress() && inetAddress instanceof Inet4Address) {

Update from 2020
Keep in mind that your user can also have IPv6 enabled. In that case you need to check for Inet6Address too.

I couldn't find something better than converting to Inet4Address or Inet6Address

public boolean isValidIp4Address(final String hostName) {
      try {
         return Inet4Address.getByName(hostName) != null;
     } catch (UnknownHostException ex) {
         return false;
     } 
}

public boolean isValidIp6Address(final String hostName) {
      try {
         return Inet6Address.getByName(hostName) != null;
     } catch (UnknownHostException ex) {
         return false;
     } 
}

Note, the getHostByName actually does the lookup, which isn't always desirable.

Or, you can get source of InetAddessUtils, which unlike getByName(), doesn't do the lookup, but accepts only dotted addresses. The code is really tiny. It uses regexp classes which are supported by Android. Just remove Immutable annotation which isn't really important, and it will compile!

Add below to your build.gradle(Module:app) file,

android { useLibrary 'org.apache.http.legacy' }