这有帮助吗？
Calendar c = Calendar.getInstance();// set the calendar to start of todayc.set(Calendar.HOUR_OF_DAY, 0);c.set(Calendar.MINUTE, 0);c.set(Calendar.SECOND, 0);c.set(Calendar.MILLISECOND, 0);// and get that as a DateDate today = c.getTime();// or as a timestamp in millisecondslong todayInMillis = c.getTimeInMillis();// user-specified date which you are testing// let's say the components come from a form or somethingint year = 2011;int month = 5;int dayOfMonth = 20;// reuse the calendar to set user specified datec.set(Calendar.YEAR, year);c.set(Calendar.MONTH, month);c.set(Calendar.DAY_OF_MONTH, dayOfMonth);// and get that as a DateDate dateSpecified = c.getTime();// test your conditionif (dateSpecified.before(today)) { System.err.println("Date specified [" + dateSpecified + "] is before today [" + today + "]");} else { System.err.println("Date specified [" + dateSpecified + "] is NOT before today [" + today + "]");}
