Calender c = Calender.getInstance();
//Calender ，Calender.getInstance(); GregorianCalender
c.get(XX)//
c.get(c.YEAR);c.get(c.MONTH);c.get(c.DAY_OF_MONTH);
c.get(c.HOUR)......
c.add(c.DAY_OF_YEAR,315); // c 315
：Calendar.DATE =Calendar.DAY_OF_MONTH 5。。。 。。？
Calendar.DATE set ， c.set(Calendar.Date) ;
Calendar.DAY_OF_MONTH c.get(Calendar.DAY_OF_MONTH); ,
c.get(Calendar.DAY_OF_WEEK); ， 。。。
DAY_OF_WEEK_IN_MONTH： day
DAY_OF_YEAR ： day
Calendar.Hour ---- 10 c.get(Calendar.Hour) 10
16 ， c.get(Calendar.Hour) ; 4
c.set(Calendar.HOUR,1); 13 ---
Calendar.HOUR_OF_DAY ---- 。。。 16 16
c.set(Calendar.HOUR_OF_DAY ,1);
：c.set(Calendar.DATE,40); ， ，set ， 。。。
Calender Data..... Date，
String Date 。。。
String Date ，
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Date d = sdf.parse("2003-05-03");
Date String 。。。 ， SimpleDateFormat sdf = new SimpleDateFormat("yyyy MM dd ");
String s = sdf.format(d);
------------------------------------------------------------------
1.
Calendar time=Calendar.getInstance();
time.clear();
time.set(Calendar.YEAR,year); //year int
time.set(Calendar.MONTH,i-1);// ,Calendar 0
int day=time.getActualMaximum(Calendar.DAY_OF_MONTH);//
： set ， clear ，
2.Calendar Date
(1) Calendar Date
Calendar cal=Calendar.getInstance();
Date date=cal.getTime();
(2) Date Calendar
Date date=new Date();
Calendar cal=Calendar.getInstance();
cal.setTime(date);
3. （ ）
Date date=new Date();
SimpleDateFormat df=new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
String time=df.format(date);
System.out.println(time);
4.
(1)
Calendar cal=Calendar.getInstance();
cal.set(Calendar.YEAR, 2006);
cal.set(Calendar.MONTH,;
cal.set(Calendar.DAY_OF_MONTH, 3);
int weekno=cal.get(Calendar.WEEK_OF_YEAR);
(2)
SimpleDateFormat df=new SimpleDateFormat("yyyy-MM-dd");
Calendar cal=Calendar.getInstance();
cal.set(Calendar.YEAR, 2006);
cal.set(Calendar.WEEK_OF_YEAR, 1);
cal.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
System.out.println(df.format(cal.getTime()));
:
2006-01-02
5.add() roll() ( )
(1)add()
SimpleDateFormat df=new SimpleDateFormat("yyyy-MM-dd");
Calendar cal=Calendar.getInstance();
cal.set(Calendar.YEAR, 2006);
cal.set(Calendar.MONTH,;
cal.set(Calendar.DAY_OF_MONTH, 3);
cal.add(Calendar.DATE, -4);
Date date=cal.getTime();
System.out.println(df.format(date));
cal.add(Calendar.DATE, 4);
date=cal.getTime();
System.out.println(df.format(date));
：
2006-08-30
2006-09-03
(2)roll
cal.set(Calendar.YEAR, 2006);
cal.set(Calendar.MONTH,;
cal.set(Calendar.DAY_OF_MONTH, 3);
cal.roll(Calendar.DATE, -4);
date=cal.getTime();
System.out.println(df.format(date));
cal.roll(Calendar.DATE, 4);
date=cal.getTime();
System.out.println(df.format(date));
：
2006-09-29
2006-09-03
，roll() ， add() ；
6. （ ）
(1) Calendar
public int getIntervalDays(Calendar startday,Calendar endday)...{
if(startday.after(endday))...{
Calendar cal=startday;
startday=endday;
endday=cal;
}
long sl=startday.getTimeInMillis();
long el=endday.getTimeInMillis();
long ei=el-sl;
return (int)(ei/(1000*60*60*24));
}
(2) Date
public int getIntervalDays(Date startday,Date endday)...{
if(startday.after(endday))...{
Date cal=startday;
startday=endday;
endday=cal;
}
long sl=startday.getTime();
long el=endday.getTime();
long ei=el-sl;
return (int)(ei/(1000*60*60*24));
}
(3)
public int getDaysBetween (Calendar d1, Calendar d2) ...{
if (d1.after(d2)) ...{
java.util.Calendar swap = d1;
d1 = d2;
d2 = swap;
}
int days = d2.get(Calendar.DAY_OF_YEAR) - d1.get(Calendar.DAY_OF_YEAR);
int y2 = d2.get(Calendar.YEAR);
if (d1.get(Calendar.YEAR) != y2) ...{
d1 = (Calendar) d1.clone();
do ...{
days += d1.getActualMaximum(Calendar.DAY_OF_YEAR);//
d1.add(Calendar.YEAR, 1);
} while (d1.get(Calendar.YEAR) != y2);
}
return days;
}
： ， （ － ） long
：1 （ ）
java.util.Date myDate=new java.util.Date();
long myTime=(myDate.getTime()/1000)-60*60*24*365;
myDate.setTime(myTime*1000);
String mDate=formatter.format(myDate);
7. String Date ，Long （ ）
（ ， SimpleDateFormat ）
， substring －－long－
java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("M/dd/yyyy hh:mm:ss a",java.util.Locale.US);
java.util.Date d = sdf.parse("5/13/2003 10:31:37 AM");
long dvalue=d.getTime();
SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
String mDateTime1=formatter.format(d);
8.
SimpleDateFormat formatter2 = new SimpleDateFormat("yyyy-MM F E");
java.util.Date date2= formatter2.parse("2003-05 5 ");
SimpleDateFormat formatter3 = new SimpleDateFormat("yyyy-MM-dd");
String mydate2=formatter3.format(date2);
mydate= myFormatter.parse("2001-1-1");
SimpleDateFormat formatter4 = new SimpleDateFormat("E");
String mydate3=formatter4.format(mydate);
9. java
web ， ， 。 oracle Date ， ， java.sql.Date ， MSsqlserver DateTime ， ， java.sql.Timestamp
dateFormat ，
class Datetest{
*method timestamp（ java.sql.Timestamp）
*@param dateString timestamp
*@return dataTime timestamp
public final static java.sql.Timestamp string2Time(String dateString)
throws java.text.ParseException {
DateFormat dateFormat;
dateFormat = new SimpleDateFormat("yyyy-MM-dd kk:mm:ss.SSS", Locale.ENGLISH);//
//dateFormat = new SimpleDateFormat("yyyy-MM-dd kk:mm:ss", Locale.ENGLISH);
dateFormat.setLenient(false);
java.util.Date timeDate = dateFormat.parse(dateString);//util
java.sql.Timestamp dateTime = new java.sql.Timestamp(timeDate.getTime());//Timestamp ,timeDate.getTime() long
return dateTime;
}
*method Date（java.sql.Date）
*@param dateString Date
*@return dataTime Date
public final static java.sql.Date string2Date(String dateString)
throws java.lang.Exception {
DateFormat dateFormat;
dateFormat = new SimpleDateFormat("yyyy-MM-dd", Locale.ENGLISH);
dateFormat.setLenient(false);
java.util.Date timeDate = dateFormat.parse(dateString);//util
java.sql.Date dateTime = new java.sql.Date(timeDate.getTime());//sql
return dateTime;
}
public static void main(String[] args){
Date da = new Date();
： da.getTime() long
System.out.println(da.getTime());
date timestamp
： new Timestamp(long)
Timestamp t = new Timestamp(new Date().getTime());
System.out.println(t);
： Timestamp(int year,int month,int date,int hour,int minute,int second,int nano)
Timestamp tt = new Timestamp(Calendar.getInstance().get(
Calendar.YEAR) - 1900, Calendar.getInstance().get(
Calendar.MONTH), Calendar.getInstance().get(
Calendar.DATE), Calendar.getInstance().get(
Calendar.HOUR), Calendar.getInstance().get(
Calendar.MINUTE), Calendar.getInstance().get(
Calendar.SECOND), 0);
System.out.println(tt);
try {
String sToDate = "2005-8-18";// java.sql.Date
String sToTimestamp = "2005-8-18 14:21:12.123";// java.sql.Timestamp
Date date1 = string2Date(sToDate);
Timestamp date2 = string2Time(sToTimestamp);
System.out.println("Date:"+date1.toString());//
System.out.println("Timestamp:"+date2.toString());//
}catch(Exception e) {
e.printStackTrace();
}
}
}