将毫秒转换成日期 再将日期转换成毫秒代码:
public static void main(String[] args) throws ParseException {
DateFormat dateFo = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
//毫秒转为日期
//long currentTime = System.currentTimeMillis();//获得现在的时间的毫秒数
long anyTime = new Long("1316493045000");//将任意字符型的毫秒数转换成long型
Calendar calendar = Calendar.getInstance();
//calendar.setTimeInMillis(currentTime);
calendar.setTimeInMillis(anyTime);
System.out.println(dateFo.format(calendar.getTime()));
// 日期转换为毫秒
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String dateTime = "2011-09-20 12:30:45";
long timeInMillis = sdf.parse(dateTime).getTime();
System.out.println(timeInMillis);
}