求两个时间差的天数、小时、分钟、秒

SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

Date d1 = null;
Date d2 = null;

try {
d1 = format.parse(dateStart);
d2 = format.parse(dateStop);

//毫秒ms
long diff = d2.getTime() - d1.getTime();

long diffSeconds = diff / 1000 % 60;
long diffMinutes = diff / (60 * 1000) % 60;
long diffHours = diff / (60 * 60 * 1000) % 24;
long diffDays = diff / (24 * 60 * 60 * 1000);

System.out.print("两个时间相差：");
System.out.print(diffDays + " 天, ");
System.out.print(diffHours + " 小时, ");
System.out.print(diffMinutes + " 分钟, ");
System.out.print(diffSeconds + " 秒.");

} catch (Exception e) {
e.printStackTrace();
}