poi-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Andrew C. Oliver" <acoli...@apache.org>
Subject Re: event model vs iterating over rows
Date Wed, 16 Jul 2003 14:06:33 GMT
Generally if the data structures YOU choose are efficient, the event model
will be faster/more memory efficient.

On 7/16/03 9:34 AM, "Brook Stevens" <bstevens@Cleanwise.com> wrote:

> Okay, so given this is it still better to use the event model or is
> iterating over the rows going to be better preformance wise, or is it a
> ratio based on the file size?
> 
> Thanks,
> Brook
> 
>> -----Original Message-----
>> From: Andrew C. Oliver [mailto:acoliver@apache.org]
>> Sent: Tuesday, July 15, 2003 9:46 PM
>> To: POI Users List
>> Subject: Re: event model vs iterating over rows
>> 
>> 
>> The rows are returned in the order in which they are in the
>> file.  There is
>> NOTHING to guarantee that the row records will be before the
>> cell records,
>> group the cell records, etc.  You must just process cell and
>> row records
>> wherever they pop up independently as any order is valid.
>> You could make
>> some assumptions that would work "most of the time" but its not the 90
>> sheets you read that people remember, its the 10 you don't.
>> 
>> For CSV, you'll probably need to add cells to some kind of
>> data structure.
>> Basically a 2 dimensional array or List of some kind then iterate over
>> supposing you wish to use the event model.
>> 
>> -Andy
>> 
>> On 7/15/03 6:51 PM, "Brook Stevens" <bstevens@Cleanwise.com> wrote:
>> 
>>> I am new to POI so please excuse me if this is a stupid question.
>>> 
>>> I am trying to write a very simple excel reader that
>> essentially will
>>> process information row by row, and could be potentially
>> large files.  The
>>> way I would do this with a csv file (which is what I am
>> replacing) is to
>>> simply read in each row.  I looked at the example on
>> Javaworld which seems
>>> to do this, but mentions that the event model is better,
>> fine so now I am
>>> looking at using the event model.  My issue is that I don't really
>>> understand if with the event model everything is in the
>> order that I expect
>>> it to be... i.e. if the last record was in row 2 and the record I am
>>> processing now is in row 3 will there be any subsequent
>> records in row 2.
>>> Or do I need to read in the entire file before I am
>> positive that I have
>>> everything in row 2.  And if that is the case would it just
>> be better to
>>> iterate over the rows.
>>> Hope I am making some sense, thanks.
>>> 
>>> Brook
>>> 
>> 
>> -- 
>> Andrew C. Oliver
>> http://www.superlinksoftware.com/poi.jsp
>> Custom enhancements and Commercial Implementation for Jakarta POI
>> 
>> http://jakarta.apache.org/poi
>> For Java and Excel, Got POI?
>> 
>> 
>> ---------------------------------------------------------------------
>> To unsubscribe, e-mail: poi-user-unsubscribe@jakarta.apache.org
>> For additional commands, e-mail: poi-user-help@jakarta.apache.org
>> 
> 

-- 
Andrew C. Oliver
http://www.superlinksoftware.com/poi.jsp
Custom enhancements and Commercial Implementation for Jakarta POI

http://jakarta.apache.org/poi
For Java and Excel, Got POI?


Mime
View raw message