遠程服務器上文件的Last-Modified 格式化

URL urlA = new URL(url);
HttpURLConnection urlcon = (HttpURLConnection) urlA.openConnection();
String lastModified = urlcon.getHeaderField("Last-Modified");
if(StringUtils.isNotBlank(lastModified)){
    String format = "EEE, dd MMM yyyy HH:mm:ss zzz";
    SimpleDateFormat sdf = new SimpleDateFormat(format, Locale.US);
    sdf.setTimeZone(TimeZone.getTimeZone("GMT")); 
    Date d = sdf.parse(lastModified); 
}