How to get proxy settings from system settings in Java

I'm looking form way how to get system proxy information in Java under Windows, but I've found just one way. But it does not work for me.

public static void main(String[] args) throws Throwable {
  System.setProperty("java.net.useSystemProxies", "true");
  System.out.println("detecting proxies");
  List<Proxy> pl = ProxySelector.getDefault().select(new URI("http://ihned.cz/"));
  for (Proxy p : pl)
    System.out.println(p);
  Proxy p = null;
  if (pl.size() > 0) //uses first one
    p = pl.get(0);
  System.out.println(p.address());
  System.out.println("Done");
}

When I run the program, I get:

detecting proxies
DIRECT
null
Done

Java means, that I'm situated directly on internet. But it's wrong. I'm behind proxy. I'm unable to get the solution for my computer.