Calendar API in java

**Miles Runner** · 05-02-2010

Hello,
I have a concern with the Calendar API in java. I run the following code:

Code:

      String str = "200901";
        Calendar cal = new GregorianCalendar();
        cal.set(Calendar.YEAR, Integer.function valueOf() {
    [native code]
}(str.substring(0, 4));
        cal.set(Calendar.WEEK_OF_YEAR, Integer.function valueOf() {
    [native code]
}(str.substring(4, 6));

I would like my calendar points to the 1st week of 2009. But it points after:

Code:

 new GregorianCalendar()

Any help on this?

**Linux-Us** · 05-02-2010

Hi,
Already I'd have to start with a calendar.clear () to have an empty date and clean, with no data "clean". It will point to the 1st week of 2008. (And here I understand that to one weeks less than the previous decrements me my year but how do I get around?). Your code works but I bet you the wrong poster, which is the case if you simply display the week number and year, the first week of 2009 begins December 29 2008. You have to correct this first.

**Miles Runner** · 05-02-2010

Hello,
Thank you for your reply. I have to initialize a calendar with the fields corresponding to 4 YEAR first character of the area and 200,901 WEEK OF YEAR 2 with the following. For the moment I can not and I agree with you on the fact that the first week of 2009 begins December 29, 2008. But when I get the year and week I have the problem of decrement of the year by setting my week. Thank you in advance.

**SoftWore** · 05-02-2010

Hello,
If I am not wrong there is no decrement. Calendar as SimpleDateFormat allows you to get a date. By specifying only the year and week number, you get in this case the first day of the first week of 2009. i.e the December 29, 2008. If you only view the year and number of weeks of this date, you will 2008 and 01. I think you have not understood the concept clearly. First get the concept clear and then program it, it will be easier for you.

**NetworkeR** · 05-02-2010

Hello,
I think you have a problem in he following code, just see, I will try to explain you. The next method you return a week. For example the 1st week of 2009 is id '200901 '.

Code:

    Public static String identifier(Calendar cal) {
        return String.function valueOf() {
    [native code]
}(cal.get(Calendar.YEAR)) + DOUBLE_ZERO_FORMAT.format(cal.get(Calendar.WEEK_OF_YEAR));
    }

If you give it January 2, 2009, the method will returns you 200,901.
But December 30, 2008 returned 200,801 when you want 200,901. Hope you got the point what I am trying to explain you.

**Windowed** · 05-02-2010

Hello,
I have a code with me, please check out, i thin it will help you. it is very simple. I hope you will understand it and interpret in your program.

Code:

 Public static String identifier(Calendar calendar) {
    	int = calendar mn.get(Calendar.MONTH);
    	int = calendar yr.get(Calendar.YEAR);
    	int = calendar wk.get(Calendar.WEEK_OF_YEAR);
    	    	
    	if (mn == Calendar.DECEMBER & & Week ==1) {
    		/ / If it is in December on the wk No. 1:
    		/ / We must add a yr:
    		yr + +;
    	} else if (mn == Calendar.JANUARY & & Week>10) {
    		/ / If we're in January on one of the last wks (I took off: have:)
    		/ / We must remove a yr:
    		yr -;
    	}
        return String.format("% 04d% 02d", Year, wk);
    }