// Compare last-modified dates
String lastModifiedString = conn.getHeaderField("Last-Modified");
if (lastModifiedString == null) {
return false;
} else {
HttpDate date = new HttpDate();
date.parse(lastModifiedString);
long remoteModifiedTime = date.getTime();
long localModifiedTime = file.lastModified();
return remoteModifiedTime > localModifiedTime;
}