參考

https://www.cnblogs.com/mstk/p/3535659.html

1

獲取時間

通過Calendar類/Date類可以獲取時間

Calendar類可以方便的獲取某個時間引數,時間字串需要自己組合

        cal = Calendar.getInstance();
        cal.setTimeZone(TimeZone.getTimeZone("GMT+8:00"));
         
        year = String.valueOf(cal.get(Calendar.YEAR));
        month = String.valueOf(cal.get(Calendar.MONTH))+1;
        day = String.valueOf(cal.get(Calendar.DATE));
        if (cal.get(Calendar.AM_PM) == 0){
             hour = String.valueOf(cal.get(Calendar.HOUR));
        } else{
             hour = String.valueOf(cal.get(Calendar.HOUR)+12);
        }
            
        minute = String.valueOf(cal.get(Calendar.MINUTE));
        second = String.valueOf(cal.get(Calendar.SECOND));
         
        my_time_1 = year + "-" + month + "-" + day;
        my_time_2 = hour + "-" + minute + "-" + second;
 

Date類相反

        Date dt = new Date();
        String str_time = dt.toLocaleString();

可以通過SimpleDateFormat類獲取自己想要的時間格式

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm E");
str_time = sdf.format(dt);

2

比較時間的大小

Date類/Calendar類都有自帶的before()/after()方法用來比較大小

也可以轉化成相同格式的字串,通過String類自帶的CompareTo()方法比較時間/日期的大小