Calendar,Date,String之间的转换
1,转换为String,方法如下:

public String convertDateToString(long dateTimes) {Calendar ca = Calendar.getInstance();ca.setTimeInMillis(dateTimes);SimpleDateFormat s = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");String 
dateString = s.format(ca.getTime());
return dateString;
}

public long convertStringToDate(String dateStr) throws ParseException {SimpleDateFormat s = new SimpleDateFormat("yyyy-MM-dd");Calendar ca = Calendar.getInstance();ca.setTime(s.parse(dateStr));return ca.getTimeInMillis();}