Date 与 LocalDateTime 转换以及LocalDateTime 和字符串互转

LocalDateTime 和字符串互转

    private static void testDateTimeFormatter() {
        // 日期 ---> 字符串
        LocalDateTime localDateTime = LocalDateTime.now();
        DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyyMMddHHmmss");
        String format = dateTimeFormatter.format(localDateTime);
        System.out.println(format);

        // 字符串 ---> 日期
        String str = "20210514100404";
        LocalDateTime localDateTime1 = LocalDateTime.parse(str, dateTimeFormatter);
        System.out.println(localDateTime1);
    }

Date 与 LocalDateTime 转换

    private static void testDateTimeFormatterCast() {
        //将java.util.Date 转换为java8 的java.time.LocalDateTime,默认时区为东8区
        Date date = new Date();
        LocalDateTime localDateTime = date.toInstant().atZone(ZoneId.systemDefault()).toLocalDateTime();
        System.out.println(localDateTime);

        //将java8 的 java.time.LocalDateTime 转换为 java.util.Date，默认时区为东8区
        Date date1 = Date.from(localDateTime.atZone(ZoneId.systemDefault()).toInstant());
        System.out.println(date1);
    }

LocalDateTime 和字符串互转执行结果

20210514103035
2021-05-14T10:04:04

Date 与 LocalDateTime 转换执行结果
2021-05-14T10:30:35.755
Fri May 14 10:30:35 CST 2021