JAvaでよく使われる時間関数

3 －

 new Date().getTime();
 System.currentTimeMillis();
 Calendar.getInstance().getTimeInMIllis();   //      

Date()

Date date = new Date();
Date date = new Date(2017,12,11);
      
String str = date.toString();
            
String str = date.toLocalString();

SimpleFormatDate()

//SimpleDateFormat(String pattern, Local local)
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH-mm-ss",);
//    
//format Date String
String str = sdf.format(new Date());
//parse  String Date
Date day = sdf.parse("2017-10-27 13:24:55:333");

ビット数時間は自動的に相就長に増加し、倍数が長い場合は対応する長さの前に0を補う.

y          2017  
M          12
d          11
H         17
h         5
m          26
s          30
S         385
E            
D    /    345
a    /     
z         CST

Calender()

Calendar c = Calendar.getInstance();
Calendar.getInstance().getTime()        Date()  
Calendar.getInstance().setTime()

int num = c.YEAR;   //         
int num = c.get(Calendar.YEAR);    //   
int num = c.get(Calendar.DATE);    //    
Calendar.MONTH/DATE/HOUR_OF_DAY/MINIUTE/SECOND