java中获取当前时间

1、 通过localDate类获取(不常见)

https://www.cnblogs.com/qingyunfc/p/10236734.html
可以通过这个来了解

        LocalDate localDate = LocalDate.now();
        LocalTime localTime = LocalTime.now();
        LocalDateTime localDateTime = LocalDateTime.now();
        System.out.println("LocalDate.now():"+localDate);
        System.out.println("LocalTime.now():"+localTime);
        System.out.println("LocalDateTime.now():"+localDateTime);

2、 Date类获取

      Date date = new Date();
       System.out.println(date.getTime());

3 、System类获取

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

4、 使用 SimpleDateFormat

     //设置日期格式
       SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
       // new Date()为获取当前系统时间
       System.out.println(df.format(new Date()));

5 、通过sql包下的Timestamp类获取，精确到毫秒，格式为：yyyy-MM-dd :hh:mm:ss:nnn

       System.out.println(new Timestamp(System.currentTimeMillis()));

6 获取当前时间，可以获取单个时间域，通过Util包下的Calendar获取

        // 可以对每个时间域单独修改
       Calendar c = Calendar.getInstance();
       int year = c.get(Calendar.YEAR);
       int month = c.get(Calendar.MONTH+1);
       int date1 = c.get(Calendar.DATE);
       int hour = c.get(Calendar.HOUR_OF_DAY);
       int minute = c.get(Calendar.MINUTE);
       int second = c.get(Calendar.SECOND);
       System.out.println(year + "/" + month + "/" + date1 + " " + hour + ":" + minute + ":" + second);

本篇主要参考了https://blog.csdn.net/a549654065/article/details/88687543