If you are using Java 2, you should create a URLConnection object from the URL object and set the following system properties: 



    URLConnection conn = url.openConnection();

    // Use the username and password you use to
    // connect to the outside world
    // if your proxy server requires authentication.
    String authentication = "Basic " + new
sun.misc.BASE64Encoder().encode("username:password".getBytes());

    System.getProperties().put("proxySet", "true");

    System.getProperties().put("proxyHost", PROXY_HOST); // your proxy host
    System.getProperties().put("proxyPort", PROXY_PORT); // your proxy port
    conn.setRequestProperty("Proxy-Authorization", authentication);


If you are using JDK 1.1, you may not be able to set the system properties. In that case, you should create the java.net.URL object with your proxy server information: 



    url = new URL("http", PROXY_HOST,
                  Integer.parseInt(PROXY_PORT),
                  fileURL );
    // assumes authentication is not required