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Bigger warnings that new users should use SXSSF, and not mess around with the XML themselves

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git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1696019 13f79535-47bb-0310-9956-ffa450edef68
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Nick Burch 2015-08-15 07:29:27 +00:00
parent 6be4fc05d2
commit 2df37edbae
1 changed files with 17 additions and 8 deletions
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src/examples/src/org/apache/poi/xssf/usermodel/examples/BigGridDemo.java
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@ -32,19 +32,28 @@ import org.apache.poi.xssf.usermodel.*;
/**
* Demonstrates a workaround you can use to generate large workbooks and avoid OutOfMemory exception.
*
* The trick is as follows:
* Note - You probably <em>don't want to use this approach any more</em>! POI
* now includes the SXSSF which handles all of this for you, you should
* be using that instead! This code remains mostly for historical interest.
* <p>
* See <a "http://poi.apache.org/spreadsheet/how-to.html#sxssf">
* http://poi.apache.org/spreadsheet/how-to.html#sxssf</a>.
* <p>
* If you really want to use this approach, which is also the one that SXSSF
* does for you, it works as follows:
*
* 1. create a template workbook, create sheets and global objects such as cell styles, number formats, etc.
* 2. create an application that streams data in a text file
* 3. Substitute the sheet in the template with the generated data
*
* <p>
* Since 3.8-beta3 POI provides a low-memory footprint SXSSF API which implementing the "BigGridDemo" strategy.
* XSSF is an API-compatible streaming extension of XSSF to be used when
* very large spreadsheets have to be produced, and heap space is limited.
* SXSSF achieves its low memory footprint by limiting access to the rows that
* are within a sliding window, while XSSF gives access to all rows in the
* document. Older rows that are no longer in the window become inaccessible,
* as they are written to the disk.
* Since 3.8 POI provides a low-memory footprint SXSSF API, which implements
* ths "BigGridDemo" strategy. SXSSF is an API-compatible streaming extension
* of XSSF to be used when very large spreadsheets have to be produced, and
* heap space is limited. SXSSF achieves its low memory footprint by limiting
* access to the rows that are within a sliding window, while XSSF gives access
* to all rows in the document. Older rows that are no longer in the window
* become inaccessible, as they are written to the disk.
* </p>
* See <a "http://poi.apache.org/spreadsheet/how-to.html#sxssf">
* http://poi.apache.org/spreadsheet/how-to.html#sxssf</a>.