如何判断string类型的时间是否到期

SimpleDateFormat s = new SimpleDateFormat(“yyyy-MM-dd HH:mm:ss”);
Date date = new Date();
date = s.parse(“2007-06-06 15:15:00”);
Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone(“GMT+8:00”));calendar.setTime(date);
long time = calendar.getTimeInMillis() / 1000;