Date Processing exercises in Java

Package net. HFH;

Import java. SQL. Ti

Package net. HFH;

Import java. SQL. timestamp;
Import java. Text. simpledateformat;
Import java. util. calendar;
Import java. util. date;
Import java. util. gregoriancalendar;
Import java. util. timezone;

Public class dateformat {

Public static void main (string [] ARGs ){

Long L1 = system. currenttimemillis ();
Date = new date (); // many methods of date are outdated

/*
* Simpledateformat SDF = new simpledateformat ("yyyy-mm-dd hh: mm: SS ");
* String STR = SDF. Format (date );
*/
// Serves the same purpose as the preceding two statements
String STR = new simpledateformat ("yyyy-mm-dd hh: mm: SS: SSS ")
. Format (date); // view the manual
System. Out. println (STR );

// System. Out. println (system. currenttimemillis ());

// Retrieve related information such as year, month, and day in the current date
Calendar c = calendar. getinstance (); // create an instance
Int year = C. Get (calendar. year); // obtain the year
System. Out. println (year );
Int month = C. Get (calendar. month); // obtain the month
System. Out. println (month );

// Convert the date obtained from other places, such as how to operate from the database.
Calendar C1 = calendar. getinstance ();
C1.set (2005, 4, 1 );
Int year1 = c1.get (calendar. year );
System. Out. println ("year1 ----" + year1 );

/*
// Why cannot I display the time correctly?
Date d = new date (, 3); Calendar C2 = calendar. getinstance ();
C2.settime (d); int year2 = c2.get (calendar. year );
System. Out. println (New simpledateformat ("YYYY"). Format (d ));
System. Out. println (year2 );
*/

// Retrieve and format the time from the database
/*
Date = Rs. getdate ("cdate ");
Simpledateformat SDF = new simpledateformat ("HH: mm: SS"); // when this cannot be displayed, all are the same
System. Out. println (SDF. Format (date ));
*/

/*
// The related date and time can be correctly displayed.
Timestamp Ts = Rs. gettimestamp ("cdate"); // Timestamp
Simpledateformat SDF = new simpledateformat ("HH: mm: SS ");
Simpledateformat sdf1 = new simpledateformat ("yyyy-mm-dd hh: mm: SS ");
System. Out. println (SDF. Format (TS ));
System. Out. println (sdf1.format (TS ));
*/

// Method for obtaining the current time
// System. currenttimemillis ();
// Date d = new date ();
// Calendar C2 = calendar. getinstance ();

// Convert string to date format
// String sdate = "2008-8-8 ";
// Java. SQL. Date SD =
// Java. SQL. Date. valueof (sdate); // This method is commonly used, for example, convert the string retrieved from the database to the Time Format
// System. Out. println ("SD ---" + SD );
// String sdate1 = ". 0 ";
// Timestamp Ts = timestamp. valueof (sdate1 );
// System. Out. println ("Ts =" + TS );

// Time Zone Processing
// Obtain the time of Japan
Timezone tzjapan = timezone. gettimezone ("Japan"); // obtain the time zone
Calendar cjapan = new gregoriancalendar (tzjapan); // The internal parameter is ID. You can use the following method to obtain the ID:
System. Out. println (cjapan. Get (calendar. hour_of_day ));

// Obtain each valid ID
// Method 1
String [] Ss = timezone. getavailableids ();
For (INT I = 0; I <ss. length; I ++ ){
System. Out. println (ss [I]);
}
// Method 2
/*
For (string str2: timezone. getavailableids ()){
System. Out. println (str2 );
}
*/

Long L2 = system. currenttimemillis ();
System. Out. println ("execution time:" + (l2-l1) + "millisecond ");
}

}

Mestamp;
Import java. Text. simpledateformat;
Import java. util. calendar;
Import java. util. date;
Import java. util. gregoriancalendar;
Import java. util. timezone;

Public class dateformat {

Public static void main (string [] ARGs ){

Long L1 = system. currenttimemillis ();
Date = new date (); // many methods of date are outdated

/*
* Simpledateformat SDF = new simpledateformat ("yyyy-mm-dd hh: mm: SS ");
* String STR = SDF. Format (date );
*/
// Serves the same purpose as the preceding two statements
String STR = new simpledateformat ("yyyy-mm-dd hh: mm: SS: SSS ")
. Format (date); // view the manual
System. Out. println (STR );

// System. Out. println (system. currenttimemillis ());

// Retrieve related information such as year, month, and day in the current date
Calendar c = calendar. getinstance (); // create an instance
Int year = C. Get (calendar. year); // obtain the year
System. Out. println (year );
Int month = C. Get (calendar. month); // obtain the month
System. Out. println (month );

// Convert the date obtained from other places, such as how to operate from the database.
Calendar C1 = calendar. getinstance ();
C1.set (2005, 4, 1 );
Int year1 = c1.get (calendar. year );
System. Out. println ("year1 ----" + year1 );

/*
// Why cannot I display the time correctly?
Date d = new date (, 3); Calendar C2 = calendar. getinstance ();
C2.settime (d); int year2 = c2.get (calendar. year );
System. Out. println (New simpledateformat ("YYYY"). Format (d ));
System. Out. println (year2 );
*/

// Retrieve and format the time from the database
/*
Date = Rs. getdate ("cdate ");
Simpledateformat SDF = new simpledateformat ("HH: mm: SS"); // when this cannot be displayed, all are the same
System. Out. println (SDF. Format (date ));
*/

/*
// The related date and time can be correctly displayed.
Timestamp Ts = Rs. gettimestamp ("cdate"); // Timestamp
Simpledateformat SDF = new simpledateformat ("HH: mm: SS ");
Simpledateformat sdf1 = new simpledateformat ("yyyy-mm-dd hh: mm: SS ");
System. Out. println (SDF. Format (TS ));
System. Out. println (sdf1.format (TS ));
*/

// Method for obtaining the current time
// System. currenttimemillis ();
// Date d = new date ();
// Calendar C2 = calendar. getinstance ();

// Convert string to date format
// String sdate = "2008-8-8 ";
// Java. SQL. Date SD =
// Java. SQL. Date. valueof (sdate); // This method is commonly used, for example, convert the string retrieved from the database to the Time Format
// System. Out. println ("SD ---" + SD );
// String sdate1 = ". 0 ";
// Timestamp Ts = timestamp. valueof (sdate1 );
// System. Out. println ("Ts =" + TS );

// Time Zone Processing
// Obtain the time of Japan
Timezone tzjapan = timezone. gettimezone ("Japan"); // obtain the time zone
Calendar cjapan = new gregoriancalendar (tzjapan); // The internal parameter is ID. You can use the following method to obtain the ID:
System. Out. println (cjapan. Get (calendar. hour_of_day ));

// Obtain each valid ID
// Method 1
String [] Ss = timezone. getavailableids ();
For (INT I = 0; I <ss. length; I ++ ){
System. Out. println (ss [I]);
}
// Method 2
/*
For (string str2: timezone. getavailableids ()){
System. Out. println (str2 );
}
*/

Long L2 = system. currenttimemillis ();
System. Out. println ("execution time:" + (l2-l1) + "millisecond ");
}

}