how to get 3 days less than current date in java

[Praveen palukuri]

hi,
this is praveen, now i have one problem before me.
"I need to display 3 days less than current date". this we can do manually by getting current date & subtracting that from 3. this is fine if date is in a month or year but when month or year is changed then we need to write lot of code.
so pls help me if any one know's simple solution for this.
thank u.

[Stuart Gray]

The Calendar class can do this, and if you use disable the lenient parsing, it will handle the situations you describe too I believe:

GregorianCalendar cal = new GregorianCalendar(); // See note below.
cal.setLenient(false);
cal.roll(Calendar.DAY_OF_MONTH, -3)

Note that according to the API docs the Calendar version of roll is broken, but the overridden version in GregorianCalendar does the right thing. Thats why I didn't declare cal to be a Calendar in the code above.

[miguel lisboa]

use og setLenient() wont help:

import java.util.*;
 

 
class Calendario {

public static void main(String args[]) {
 
GregorianCalendar cal = new GregorianCalendar(); // See note below.
 
cal.setLenient(false);
 
cal.roll(Calendar.DAY_OF_MONTH, -12);
 
System.out.println(cal.getTime());
 
}
 
}  

Wed Jun 29 14:23:08 BST 2005

[Tim West]

This isn't necessarily the most API-correct way to do it, but:

    private static final long MILLIS_PER_DAY = 24 * 60 * 60 * 1000;
    
    public static Date addDays(Date d, int numDays)
    {
        return new Date(d.getTime() + numDays * MILLIS_PER_DAY);
    }
    
    public static void main(String[] args) {
        Date d = new Date();
        System.out.println(formatAsIso8601(d));
        Date threeLess = addDays(d, -3);
        System.out.println(formatAsIso8601(threeLess));
    }

The result:

2005-06-12T14:55:12.791
2005-06-09T14:55:12.791

If you want to run this code, you'll have to implemnt formatAsIso8601 yourself though ;-)


-Tim