在Java中获取当前日期/时间的最佳方法是什么?


当前回答

Java 8或更高版本

LocalDateTime.now() and ZonedDateTime.now()

其他回答

    // 2015/09/27 15:07:53
    System.out.println( new SimpleDateFormat("yyyy/MM/dd HH:mm:ss").format(Calendar.getInstance().getTime()) );

    // 15:07:53
    System.out.println( new SimpleDateFormat("HH:mm:ss").format(Calendar.getInstance().getTime()) );

    // 09/28/2015
    System.out.println(new SimpleDateFormat("MM/dd/yyyy").format(Calendar.getInstance().getTime()));

    // 20150928_161823
    System.out.println( new SimpleDateFormat("yyyyMMdd_HHmmss").format(Calendar.getInstance().getTime()) );

    // Mon Sep 28 16:24:28 CEST 2015
    System.out.println( Calendar.getInstance().getTime() );

    // Mon Sep 28 16:24:51 CEST 2015
    System.out.println( new Date(System.currentTimeMillis()) );

    // Mon Sep 28
    System.out.println( new Date().toString().substring(0, 10) );

    // 2015-09-28
    System.out.println( new java.sql.Date(System.currentTimeMillis()) );

    // 14:32:26
    Date d = new Date();
    System.out.println( (d.getTime() / 1000 / 60 / 60) % 24 + ":" + (d.getTime() / 1000 / 60) % 60 + ":" + (d.getTime() / 1000) % 60 );

    // 2015-09-28 17:12:35.584
    System.out.println( new Timestamp(System.currentTimeMillis()) );

    // Java 8

    // 2015-09-28T16:16:23.308+02:00[Europe/Belgrade]
    System.out.println( ZonedDateTime.now() );

    // Mon, 28 Sep 2015 16:16:23 +0200
    System.out.println( ZonedDateTime.now().format(DateTimeFormatter.RFC_1123_DATE_TIME) );

    // 2015-09-28
    System.out.println( LocalDate.now(ZoneId.of("Europe/Paris")) ); // rest zones id in ZoneId class

    // 16
    System.out.println( LocalTime.now().getHour() );

    // 2015-09-28T16:16:23.315
    System.out.println( LocalDateTime.now() );

(注意:仅适用于Java版本<8。对于Java 8+,请检查其他回复。)

如果您只需要输出格式为YYYY.MM.DD-HH.MM.SS(非常常见的情况)的时间戳,那么下面是方法:

String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(Calendar.getInstance().getTime());

你看过java.util.Date吗?这正是你想要的。

我认为这是最好的方法:

DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Calendar cal = Calendar.getInstance();
System.out.println(dateFormat.format(cal.getTime())); // 2014/08/06 16:00:22

对于java.util.Date,只需创建一个新的Date()

DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Date date = new Date();
System.out.println(dateFormat.format(date)); //2016/11/16 12:08:43

对于java.util.Calendar,使用Calendar.getInstance()

DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
Calendar cal = Calendar.getInstance();
System.out.println(dateFormat.format(cal)); //2016/11/16 12:08:43

对于java.time.LocalDateTime,使用LocalDateTime.now()

DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss");
LocalDateTime now = LocalDateTime.now();
System.out.println(dtf.format(now)); //2016/11/16 12:08:43

对于java.time.LocalDate,使用LocalDate.now()

DateTimeFormatter dtf = DateTimeFormatter.ofPattern("yyyy/MM/dd");
LocalDate localDate = LocalDate.now();
System.out.println(dtf.format(localDate)); //2016/11/16

参考:https://www.mkyong.com/java/java-how-to-get-current-date-time-date-and-calender/