set proxy host/port ???

I am attempting to connect to a local proxy to inspect my internet trafic.

The proxy is listening to port 8888 so I though the attached code would
pass through it and I would the see request/response. Nothing happens in
the
proxy.

Java seems to be ignoring the proxySet stuff. I would have been happy just
to
get an error code something like invalid port

I attempted setting these parameters with the java -D
java -DproxySet=true -Dhttp.proxyHost=127.0.0.1 -Dhttp.proxyPort=8888

Thanks for any suggestions

code example

import java.io.*;
import java.net.*;

class ProxyTest {

 public static void main(String [] args) {
  System.getProperties().put( "proxySet", "true" );
  System.getProperties().put( "http.proxySet", "true" ); //probably not
needed
  System.getProperties().put( "http.proxyHost", "ggcdell" ); // name of my
computer
  System.getProperties().put( "http.proxyPort", "8888" );
      String ht = "http://csmerge.cira.colostate.edu";
      try {
         URL url = new URL(ht);
   URLConnection conn = url.openConnection();
         conn.connect();
         DataInputStream s = new DataInputStream(conn.getInputStream());
         String line = s.readLine();
         while (line != null) {
            System.out.println(line);
            line = s.readLine();
         }
         s.close();
      } catch (Exception ee) {
         System.out.println(" should arrive here ");
         ee.printStackTrace(System.out);
      }
   }
}