(1),获取当前日期时间

String timeParse = "yyyy-MM-dd HH:mm:ss";
        SimpleDateFormat simpleDateFormat = new SimpleDateFormat(timeParse);
        String strDateTime = simpleDateFormat.format(new Date());
        System.out.println("当前系统时间:"+ strDateTime);

(2),获取今日是周几

Calendar calendar = Calendar.getInstance();
        calendar.setTime(new Date());
        int weekIdx = calendar.get(Calendar.DAY_OF_WEEK) - 1;
        switch (weekIdx) {
            case 1:
                System.out.println("今天是星期一");
                break;
            case 2:
                System.out.println("今天是星期二");
                break;
            case 3:
                System.out.println("今天是星期三");
                break;
            case 4:
                System.out.println("今天是星期四");
                break;
            case 5:
                System.out.println("今天是星期五");
            case 6:
                System.out.println("今天是星期六");
                break;
            default:
                System.out.println("今天是星期日");
                break;
        }