Using the Play! Framework (Java):

  public static void myEndpoint() {
    HttpResponse resp = WS.url("url-of-file").get();
    InputStream is = resp.getStream();
    renderBinary(is);
  }

Or am I missing something?

(EDIT: This doesn't do the zipping or multiple files -- I guess I need a ZipOutputStream to take it the rest of the way)