方法一：

        final Calendar c = Calendar.getInstance();
        year = c.get(Calendar.YEAR);
        month = c.get(Calendar.MONTH);
        day = c.get(Calendar.DATE);
        hour = c.get(Calendar.HOUR);
        minute = c.get(Calendar.MINUTE);

方法二：

        long currentTime = System.currentTimeMillis();
        String timeNow = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(currentTime);