How can i tell if Native code is being used or not?

Question

Hi,
I imported a jar file called dnsjava, and set my system property to use this so that my getHostName method doesnt use native code to get the host name. My question is, how can i know for sure that it is using the code from the jar file dnsjava? I used a debugger, and it seemed like it was getting it from java.net.InetAddress instead. Please help!
import java.net.InetAddress;
public class Test {
     public static void main(String[] args) throws Exception {
          System.setProperty("sun.net.spi.nameservice.provider.1","dns,dnsjava");
          InetAddress addr = InetAddress.getByName("64.58.76.179");
          String name = addr.getHostName();
          System.out.println("name = " + name);
}

Answer 1

What makes you think that you can set that property in the code and it will work?
A number of properties can only be set from the command line. They will not work when set in code.
I am not sure that any sun type properties will work when set in code.