时间的api

@Test
public void date(){
    LocalDateTime dateTime = LocalDateTime.now();
    DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    String format = dateTime.format(formatter);
    System.out.println("format:" + format);//2023-09-25 19:53:41

    Date date = new Date();
    System.out.println("date:" + date);//Mon Sep 25 20:12:59 CST 2023
    String string = date.toString();
    System.out.println("string:" + string);//Mon Sep 25 19:55:45 CST 2023

    Date date1 = new Date();
    SimpleDateFormat ft = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
    String format1 = ft.format(date1);
    System.out.println("format1:" + format1);//2023-09-25 19:58:20

    String dateStr1 = "2016-05-18";
    String dateStr2 = "2016-05-17 12:37:56";
    Date date3 = null;
    Date date2 = null;
    try {
        date3 = new SimpleDateFormat("yyyy-MM-dd").parse(dateStr1);
        date2 = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").parse(dateStr2);
    } catch (ParseException e) {
        e.printStackTrace();
    }
    System.out.println(date3);//Wed May 18 00:00:00 CST 2016
    System.out.println(date2);//Tue May 17 12:37:56 CST 2016

    //String dateStr = "2020-12-30 11:25:33";
    DateTimeFormatter inputFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    LocalDateTime datetime = LocalDateTime.parse(format1, inputFormatter);
    System.out.println("datetime : " + datetime);//2023-09-25T20:00:48

    long l = System.currentTimeMillis();
    System.out.println("l:" + l);//1695643386795

    Date datel = new Date(l);
    System.out.println(datel);//Mon Sep 25 20:05:25 CST 2023

    long time = datel.getTime();
    System.out.println("time:" + time);//1695643630057
}