根据已知时间计算时间差

public String getSpendTime(TechScheduleServiceBean bean) {
TechScheduleBean bean2 = bean.getBean();
long beginTime = bean2.getBegin_time().getTime();
long endTime = bean2.getEnd_time().getTime();
double days = (endTime-beginTime) / (1000 * 60 * 60 * 24);
double hours = ((endTime-beginTime) - days * (1000 * 60 * 60 * 24)) / (1000 * 60 * 60);
double minutes = ((endTime-beginTime) - days * (1000 * 60 * 60 * 24) - hours * (1000 * 60 * 60)) / (1000 * 60);
double minute = minutes / 60;
double spendtime = hours + minute;
DecimalFormat df = new DecimalFormat("#.##");
return df.format(spendtime);
}