Read java.util.Date type value from a spreadsheet.

[ynaras]

Hi, I have searched through this forum and seen only one post on this topic: http://www.oooforum.org/forum/viewtopic.phtml?t=5608&highlight=java+read+date

I am however not convinced that the solution provided will work consistently when OOO comes out with new versions. Here is a question for experienced OOO hands like Danny Brewers and Pitonyaks out there:

What is the OOO recommended way to get calc Date type values into java.util.Date type value using OOO api?

Thanks,
Yogesh.

[pitonyak]

How is the value stored in your Calc document? In other words, will you simply read a numeric value (double), or do you need to process a formatted string?

when you answer that question, then the answer should be obvious. My opinion is that the value as a numeric is easier, because then you know your starting point and you simply need to figure out how to convert it in Java. Every time that I learn the approved method in java, they seem to change it <grumble grumble>.
_________________
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Andrew Pitonyak
http://www.pitonyak.org/oo.php

[ynaras]

Thanks for the fast response Andrew. I am storing all the date values as calc Date type. In calc, I display these dates using "DD-MONTH NAME-YYYY" format as that is the least ambiguous format.

It looks like you are suggesting reading the date type as a numeric type and then using "1/1/1899" as the starting point to convert all dates. Right? i.e. the algorithm specified in the posting: http://www.oooforum.org/forum/viewtopic.phtml?t=5608&highlight=java+read+date>, Right?

I am disappointed to learn that they keep changing the approved java method.

-Yogesh

[pitonyak]

[Villeroy]

There is no data-type "date" nor "time" in a spreadsheet. Dates are doubles, starting at some day zero, incremented by one for each day. Times are the fractions of a double. Displaying dates just applies some nifty number format on a double.
Calc's day number zero is 1899-12-30 by default. The GUI lets you define two other days 1900-1-1 and 1904-1-1 (Tools>Options>Calc>Calculation), but you can set any day to be day zero.
Service com.sun.star.sheet.SpreadsheetDocumentSettings has a property com.sun.star.util.Date NullDate for each spreadsheet.
I don't program in java, but I believe there is a way to convert the NullDate of the document in question to double, add the double-value of the cell and get back the date value.

[ynaras]

Hello Andrew and Villeroy, Thanks for the information.

Actually, I am fine with the way the calculation is done. I am however concerned about OOO changing something that will cause the code to break. On the bright side, these changes keeps us geeks employed, right?

Villeroy, I will take a look at the com.sun.star.util.Date NullDate property. It looks like that is a good thing to know.

Thanks again for all the help,
Yogesh.

[pitonyak]

if you will not be using current dates, then you need to know about the strange behavior related to the calendars (I document this in my book). Can't remember the details, but the calendar changed, and then there are some issues around zero.
_________________
--
Andrew Pitonyak
http://www.pitonyak.org/oo.php