Does Java Use the right IP version?

Tmp.java

package tmp;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;

/**
 * Created by kmhaswade on 3/31/16.
 */
public class Tmp {
    public static void main(String[] args) throws IOException {
        URL u = new URL("http://localhost:8080");
        URLConnection uc = u.openConnection();
        uc.connect();
        System.out.println(System.getProperty("java.net.preferIPv6Addresses"));
        BufferedReader br = new BufferedReader(new InputStreamReader(uc.getInputStream()));
        String line;
        while ((line = br.readLine()) != null) {
            System.out.println(line);
        }
    }
}