long类型时间转换string

long commentTime = list.get(position).getCommentTime();
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
simpleDateFormat.setTimeZone(TimeZone.getTimeZone("GMT+00:00"));
// time为转换格式后的字符串
String time = simpleDateFormat.format(new Date(commentTime));
holder.textView5.setText(time + "");