1、LocalDateTime时间相减计算
public static Map calculateTimeDifference(LocalDateTime now, LocalDateTime end) {
Map maps = Maps.newHashMap();
Duration duration = Duration.between(now, end); //now - end = duration
Long days = duration.toDays(); //相差的天数
Long hours = duration.toHours();//相差的小时数
Long minutes = duration.toMinutes();//相差的分钟数
Long millis = duration.toMillis();//相差毫秒数
Long nanos = duration.tonanos();//相差的纳秒数
maps.put("days", days);
maps.put("hours", hours);
maps.put("minutes", minutes);
maps.put("millis", millis);
maps.put("nanos", nanos);
return maps;
}
public static void main(String[] args) {
//获取当前时间再加10分钟
System.out.println(calculateTimeDifference(LocalDateTime.now(), LocalDateTime.now().plusMinutes(10)));
}
2、jdk8 list.stream()根据实体类中某个字段去重返回size()
List lcaTerms = lcaTermMapper.selectByExample(lcaTermExample);
Set collect = lcaTerms.stream().map(LcaTerm::getBillNo).collect(Collectors.toSet());
return collect.size();
//类似于sql中 select distinct(BillNo) from table
