with the following Interface and allowing access to java.net.* it is possible to use own DNS provider with JDK8 and JDK9. The new Provider is installed via
"INameService.install(new MyNameService());"
public interface INameService extends InvocationHandler {
public static void install(final INameService dns) throws IllegalArgumentException, IllegalAccessException, NoSuchFieldException, SecurityException, ClassNotFoundException {
final Class<?> inetAddressClass = InetAddress.class;
Object neu;
Field nameServiceField;
try {
final Class<?> iface = Class.forName("java.net.InetAddress$NameService");
nameServiceField = inetAddressClass.getDeclaredField("nameService");
neu = Proxy.newProxyInstance(iface.getClassLoader(), new Class<?>[] { iface }, dns);
} catch(final ClassNotFoundException|NoSuchFieldException e) {
nameServiceField = inetAddressClass.getDeclaredField("nameServices");
final Class<?> iface = Class.forName("sun.net.spi.nameservice.NameService");
neu = Arrays.asList(Proxy.newProxyInstance(iface.getClassLoader(), new Class<?>[] { iface }, dns));
}
nameServiceField.setAccessible(true);
nameServiceField.set(inetAddressClass, neu);
}
/**
* Lookup a host mapping by name. Retrieve the IP addresses associated with a host
*
* @param host the specified hostname
* @return array of IP addresses for the requested host
* @throws UnknownHostException if no IP address for the {@code host} could be found
*/
InetAddress[] lookupAllHostAddr(final String host) throws UnknownHostException;
/**
* Lookup the host corresponding to the IP address provided
*
* @param addr byte array representing an IP address
* @return {@code String} representing the host name mapping
* @throws UnknownHostException
* if no host found for the specified IP address
*/
String getHostByAddr(final byte[] addr) throws UnknownHostException;
@Override default public Object invoke(final Object proxy, final Method method, final Object[] args) throws Throwable {
switch(method.getName()) {
case "lookupAllHostAddr": return lookupAllHostAddr((String)args[0]);
case "getHostByAddr" : return getHostByAddr ((byte[])args[0]);
default :
final StringBuilder o = new StringBuilder();
o.append(method.getReturnType().getCanonicalName()+" "+method.getName()+"(");
final Class<?>[] ps = method.getParameterTypes();
for(int i=0;i<ps.length;++i) {
if(i>0) o.append(", ");
o.append(ps[i].getCanonicalName()).append(" p").append(i);
}
o.append(")");
throw new UnsupportedOperationException(o.toString());
}
}
}
