java8 时间类的基本使用

淩亂°似流年 2021-09-18 04:08 306阅读 0赞

import java.time.LocalDate;
    import java.time.LocalDateTime;
    import java.time.LocalTime;
    import java.time.format.DateTimeFormatter;
    
    /**
     * description: java8 时间工具类
     * 
     * @date 2019年9月23日
     */
    public class DateUtils {
    
        private DateUtils() {
    
        }
    
        /**
         * description: 获取当前日期
         * 
         * @return 2019-09-23
         */
        public static String getNowDate() {
            LocalDate localDate = LocalDate.now();
            return localDate.toString();
        }
    
        /**
         * description: 获取 pattern 格式的当前日期
         * 
         * @param pattern
         *            日期格式
         * @return
         */
        public static String getNowDateWithPattern(String pattern) {
            LocalDate localDate = LocalDate.now();
            return localDate.format(DateTimeFormatter.ofPattern(pattern));
        }
    
        /**
         * description: 将字符串转化为 LocalDate 格式
         * 
         * @param date
         *            日期字符串
         * @param pattern
         *            日期格式
         * @return
         */
        public static LocalDate formatToDate(String date, String pattern) {
            return LocalDate.parse(date, DateTimeFormatter.ofPattern(pattern));
        }
    
        /**
         * description: 获取昨天的日期
         * 
         * @return
         */
        public static String getLastDay() {
            LocalDate localDate = LocalDate.now();
            LocalDate lastDay = localDate.minusDays(1);
            return lastDay.toString();
        }
    
        /**
         * description: 获取当前时间
         * 
         * @return 22:00:39.310
         */
        public static String getNowTime() {
            return LocalTime.now().toString();
        }
    
        public static String getNowTime(String pattern) {
            return LocalTime.now().format(DateTimeFormatter.ofPattern(pattern));
        }
    
        /**
         * description: 获取当前日期时间
         * 
         * @return
         */
        public static String getNowDateTime() {
            LocalDateTime localDateTime = LocalDateTime.now();
            return localDateTime.toString();
        }
    
        /**
         * description: 获取当前日期时间
         * 
         * @param pattern
         * @return
         */
        public static String getNowDateTime(String pattern) {
            LocalDateTime localDateTime = LocalDateTime.now();
            return localDateTime.format(DateTimeFormatter.ofPattern(pattern == null ? "yyyy-MM-dd HH:mm:ss" : pattern));
        }
    
        public static void main(String[] args) {
            System.out.println(getNowDate());
            System.out.println(getNowDateWithPattern("yyyyMMdd"));
            System.out.println(formatToDate("20190923", "yyyyMMdd"));
            System.out.println(getLastDay());
            System.out.println(getNowTime());
            System.out.println(getNowTime("HH:mm:ss"));
            System.out.println(getNowDateTime());
            System.out.println(getNowDateTime(null));
    
        }
    }
    ----------------------------------------------------------------
    2019-09-23
    20190923
    2019-09-23
    2019-09-22
    22:09:41.240
    22:09:41
    2019-09-23T22:09:41.240
    2019-09-23 22:09:41