Date issues and other issues in JSP

Date Problems
1. Get the current server Date:

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Code:

<% @ Page import = "Java. util. Date" %>
<%
Date mydate = new date ();
%>

2. Obtain the current year, month, and day:

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Code:

<% @ Page import = "Java. util. Date" %>
<%
Date mydate = new date ();
Int Thisyear = mydate. getyear () + 1900; // Thisyear = 2003
Int thismonth = mydate. getmonth () + 1; // thismonth = 5
Int thisdate = mydate. getdate (); // thisdate = 30
%>

3. output the current date by local time zone

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Code:

<% @ Page import = "Java. util. Date" %>
<%
Date mydate = new date ();
Out. println (mydate. tolocalestring ());
%>

Output result:
2003-5-30
4. Obtain the value of the field name "publish_time" and datetime type in the database.

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Code:

<% @ Page import = "Java. util. Date" %>
<%
... Connect to the database...
Resultset rs =...
Date sdate = Rs. getdate ("publish_time ");
%>
[Code]
5. Print the date in the specified format
[Code]
<% @ Page import = "Java. util. Date" %>
<% @ Page import = "Java. Text. dateformat" %>
<%
Date dnow = new date ();
Simpledateformat formatter = new simpledateformat ("e YYYY. Mm. dd' at 'hh: mm: ss a Zzz ");
Out. println ("it is" + formatter. Format (dnow ));
%>

The output result is:
It is Friday 2003.05.30 at 11:30:46 am CST
(For more detailed format symbols, see simpledateformat)
6. convert a string to a date

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Code:

<% @ Page import = "Java. util. Date" %>
<% @ Page import = "Java. Text. dateformat" %>
<%
String inputs = "1222-11-11 ";
Simpledateformat formatter = new simpledateformat ("yyyy-mm-dd ");
Date T = NULL;
Try {
T = formatter. parse (input );
Out. println (t );
} Catch (parseexception e ){
Out. println ("unparseable using" + formatter );
}
%>

Output result:
Fri Nov 11 00:00:00 CST 1222
7. interval between calculation dates

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Code:

<% @ Page import = "Java. util. Date" %>
<% @ Page import = "Java. Text. dateformat" %>
<%
String input = "2003-05-01 ";
Simpledateformat formatter = new simpledateformat ("yyyy-mm-dd ");
Date d1 = NULL;
Try {
D1 = formatter. parse (input );
} Catch (parseexception e ){
Out. println ("unparseable using" + formatter );
}

Date D2 = new date ();

Long diff = d2.gettime ()-d1.gettime ();
Out. println ("difference is" + (diff/(1000*60*60*24) + "days .");
%>

Output result:
Difference is 29 days.
8. addition and subtraction of dates
Method: Use the add () method of the calendar class

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Code:

<% @ Page import = "Java. util. *" %>
<% @ Page import = "Java. Text. *" %>
<%
Calendar now = calendar. getinstance ();
Simpledateformat formatter = new simpledateformat ("e YYYY. Mm. dd' at 'hh: mm: ss a Zzz ");
Out. println ("it is now" + formatter. Format (now. gettime ()));
Now. Add (calendar. day_of_year,-(365*2 ));
Out. println ("<br> ");
Out. println ("two years ago was" + formatter. Format (now. gettime ()));
%>

Output result:
It is now Friday 2003.05.30 at 01:45:32 pm CST
Two years ago was wed2001.05.30 at 01:45:32 pm CST
9. Comparison date
Method: Use the equals (), before (), and after () methods.

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Code:

<% @ Page import = "Java. util. *" %>
<% @ Page import = "Java. Text. *" %>
<%
Dateformat df = new simpledateformat ("yyy-mm-dd ");
Date d1 = DF. parse ("2000-01-01 ");
Date D2 = DF. parse ("maid ");

String relation = NULL;
If (d1.equals (D2 ))
Relation = "the same date ";
Else if (d1.before (D2 ))
Relation = "before ";
Else
Relation = "after ";
Out. println (d1 + "is" + Relation + ''+ D2 );
%>

Output result:
Sat Jan 01 00:00:00 CST 2000 is after Fri Dec 31 00:00:00 CST 1999
10. record the time spent on one thing
Method: Call the system. gettimemillis () method twice to calculate the difference value.

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Code:

<% @ Page import = "Java. Text. *" %>
<%
Long T0, T1;
T0 = system. currenttimemillis ();
Out. println ("Cyc starts at" + T0 );
Int K = 0;
For (INT I = 0; I <100000; I ++ ){
K + = I;
}
T1 = system. currenttimemillis ();
Out. println ("<br> ");
Out. println ("Cyc ends at" + T1 );
Out. println ("<br> ");
Out. println ("this run took" + (t1-t0) + "ms .");
%>

Output result:
Cyc starts 1054275312432
Cyc ends 1054275312442
This run took 10 ms.

Others: how to format Decimals

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Code:

<% @ Page import = "Java. Text. *" %>
<%
Decimalformat df = new decimalformat (", ###. 00 ");
Double anumber = 33665448856.6568975;
String result = DF. Format (anumber );
Out. println (result );
%>

Output result:
33,665,448,856.66