LocalDateTime、LocalDate、Long、Date、String 相互转换

清疚 2023-07-10 11:29 45阅读 0赞

DateTimeFormatter dateTimeFormatter1 = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    DateTimeFormatter dateTimeFormatter2 = DateTimeFormatter.ofPattern("yyyy-MM-dd");
    
    LocalDateTime localDateTime = LocalDateTime.parse("2019-07-31 00:00:00",dateTimeFormatter1);
    LocalDate localDate = LocalDate.parse("2019-07-31",dateTimeFormatter2);
    Date date = Date.from(LocalDateTime.parse("2019-07-31 00:00:00",dateTimeFormatter1).atZone(ZoneId.systemDefault()).toInstant());
    
    
    String strDateTime = "2019-07-31 00:00:00";
    String strDate = "2019-07-31";
    Long timestamp=1564502400000l;
    
    /** LocalDateTime 转 LocalDate */
    System.out.println("LocalDateTime 转 LocalDate: "+localDateTime.toLocalDate());
    /** LocalDateTime 转 Long */
    System.out.println("LocalDateTime 转 Long: "+localDateTime.atZone(ZoneId.systemDefault()).toInstant().toEpochMilli());
    /** LocalDateTime 转 Date */
    System.out.println("LocalDateTime 转 Date: "+Date.from(localDateTime.atZone(ZoneId.systemDefault()).toInstant()));
    /** LocalDateTime 转 String */
    System.out.println("LocalDateTime 转 String: "+localDateTime.format(dateTimeFormatter1));
    
    System.out.println("-------------------------------");
    
    /** LocalDate 转 LocalDateTime */
    System.out.println("LocalDate 转 LocalDateTime: "+LocalDateTime.of(localDate,LocalTime.parse("00:00:00")));
    /** LocalDate 转 Long */
    System.out.println("LocalDate 转 Long: "+localDate.atStartOfDay(ZoneId.systemDefault()).toInstant().toEpochMilli());
    /** LocalDate 转 Date */
    System.out.println("LocalDate 转 Date: "+Date.from(localDate.atStartOfDay().atZone(ZoneId.systemDefault()).toInstant()));
    /** LocalDate 转 String */
    System.out.println("LocalDateTime 转 String: "+localDateTime.format(dateTimeFormatter2));
    
    System.out.println("-------------------------------");
    
    /** Date 转 LocalDateTime */
    System.out.println("Date 转 LocalDateTime: "+LocalDateTime.ofInstant(date.toInstant(), ZoneId.systemDefault()));
    /** Date 转 Long */
    System.out.println("Date 转 Long: "+date.getTime());
    /** Date 转 LocalDate */
    System.out.println("Date 转 LocalDateTime: "+LocalDateTime.ofInstant(date.toInstant(), ZoneId.systemDefault()).toLocalDate());
    /** Date 转 String */
    SimpleDateFormat sdf =new SimpleDateFormat("yyyy-MM-dd HH:mm:ss SSS" );
    System.out.println("Date 转 String: "+sdf.format(date));
    
    System.out.println("-------------------------------");
    
    /** String 转 LocalDateTime */
    System.out.println("String 转 LocalDateTime: "+LocalDateTime.parse(strDateTime,dateTimeFormatter1));
    /** String 转 LocalDate */
    System.out.println("String 转 LocalDate: "+LocalDateTime.parse(strDateTime,dateTimeFormatter1).toLocalDate());
    System.out.println("String 转 LocalDate: "+LocalDate.parse(strDate,dateTimeFormatter2));
    /** String 转 Date */
    System.out.println("String 转 Date: "+Date.from(LocalDateTime.parse(strDateTime,dateTimeFormatter1).atZone(ZoneId.systemDefault()).toInstant()));
    
    System.out.println("-------------------------------");
    
    /** Long 转 LocalDateTime */
    System.out.println("Long 转 LocalDateTime:"+LocalDateTime.ofInstant(Instant.ofEpochMilli(timestamp), ZoneId.systemDefault()));
    /** Long 转 LocalDate */
    System.out.println("Long 转 LocalDate:"+LocalDateTime.ofInstant(Instant.ofEpochMilli(timestamp), ZoneId.systemDefault()).toLocalDate());