取得當前日期

Calendar cal = Calendar.getInstance();
System.out.println("年:" + cal.get(Calendar.YEAR));
// 一月為0，因此要加1
System.out.println("月:" + (cal.get(Calendar.MONTH) + 1));

System.out.println("日:" + cal.get(Calendar.DATE));

// 24小時制
System.out.println("時(24):" + cal.get(Calendar.HOUR_OF_DAY));

// 12小時制
System.out.println("時(12):" + cal.get(Calendar.HOUR)
+ (char) ('A' + cal.get(Calendar.AM_PM) * 15) + "M");

System.out.println("分:" + cal.get(Calendar.MINUTE));

System.out.println("秒:" + cal.get(Calendar.SECOND));

// 格式化時間

System.out.println(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()));
System.out.println(new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").format(new Date()));

}