计算两个日期之间的小时数

public void mytest15() throws ParseException {
String startTime = "2019-11-08 10:12:00";
String endTime = "2019-11-08 17:23:00";
DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
Date startDate = dateFormat.parse(startTime);
Date endDate = dateFormat.parse(endTime);
Integer datePoor = getDatePoor(startDate,endDate);
BigDecimal b = new BigDecimal((double)datePoor/60);
Double hour = b.setScale(2,BigDecimal.ROUND_HALF_UP).doubleValue();
//第一个参数是保留小数的位数
System.out.println(hour);}

public static Integer getDatePoor(Date startDate, Date endDate) {

    long nd = 1000 * 24 * 60 * 60;
    long nh = 1000 * 60 * 60;
    long nm = 1000 * 60;
    // long ns = 1000;
    // 获得两个时间的毫秒时间差异
    long diff = endDate.getTime() - startDate.getTime();
    // 计算差多少天
    long day = diff / nd;
    // 计算差多少小时
    long hour = diff % nd / nh;
    // 计算差多少分钟
    Long min = diff % nd % nh / nm;
    // 计算差多少秒//输出结果
    // long sec = diff % nd % nh % nm / ns;
    Long mymint = diff/1000/60;
    int intValue = mymint.intValue();
    return intValue;
}

执行程序，得到结果：7.18

public void ShowTimeInterval(Date date1, Date date2) {
long lDate1 = date1.getTime();

long lDate2 = date2.getTime();

long diff = (lDate1 < lDate2) ? (lDate2 - lDate1) : (lDate1 - lDate2);

long day = diff / (24 * 60 * 60 * 1000);

long hour = diff / (60 * 60 * 1000) - day * 24;

long min = diff / (60 * 1000) - day * 24 * 60 - hour * 60;

long sec = diff / 1000 - day * 24 * 60 * 60 - hour * 60 * 60 - min * 60;

System.out.println("date1 与 date2 相差 " + day + "天" + hour + "小时" + min + "分" + sec + "秒");
}
原文链接：https://blog.csdn.net/weixin_44665318/article/details/124844123