JDK8 获取一个月的第一（最后）一天

拼搏现实的明天。 2022-01-30 00:15 387阅读 0赞

/**
         * 获取一个月的最后一天
         * @return
         * @exception
         * @date       2019/5/17 10:35
         */
        public static String getLastDayOfMonth() {
            LocalDate today = LocalDate.now();
            LocalDate lastDay = today.with(TemporalAdjusters.lastDayOfMonth());
            LocalDateTime lastDayTime = localDateToLocalDateTime(lastDay);
            return localDateTime2YMDHMS(lastDayTime);
        }
    
    
      /**
         * LocalDate To LocalDateTime
         * @return
         * @exception
         * @date       2019/5/17 14:13
         */
        public static LocalDateTime localDateToLocalDateTime(LocalDate localDate) {
    
            ZoneId zone = ZoneId.systemDefault();
            Instant instant = localDate.atStartOfDay().atZone(zone).toInstant();
            Date date =  Date.from(instant);
    
            instant = date.toInstant();
            zone = ZoneId.systemDefault();
           return LocalDateTime.ofInstant(instant, zone);
        }
    
     /**
         * 获取一个月的第一天
         * @return
         * @exception
         * @date       2019/5/17 10:34
         */
        public static String getFirstDayOfMonth() {
            LocalDate today = LocalDate.now();
            LocalDate firstday = LocalDate.of(today.getYear(),today.getMonth(),1);
            LocalDateTime firstDayTime = localDateToLocalDateTime(firstday);
            return localDateTime2YMDHMS(firstDayTime);
        }
    
    
     /**
         * localDateTime2YMDHMS
         * 返回的格式为 yyyy-MM-dd HH:mm:ss
         *
         * @return
         * @throws
         * @date 2019/1/7 12:04
         */
        public static String localDateTime2YMDHMS(LocalDateTime localDateTime) {
            DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
            return df.format(localDateTime);
        }