Editing Apache POI

{{Short description|Open-source API to access Microsoft Office formats}}
{{Use mdy dates|date=May 2024}}
{{Infobox software
| name = Apache POI
| logo = Apache_POI_project_logo_(2018).svg
| screenshot = 
| caption = 
| developer = [[Apache Software Foundation]]
| latest release version = 5.4.1
| latest release date = {{Start date and age|2025|4|6}}<ref>{{cite web |url=https://poi.apache.org/changes.html |title=History of Changes |access-date=2025-04-06}}</ref>
| latest preview version = 
| latest preview date = 
| repo = {{URL|https://svn.apache.org/repos/asf/poi/|POI Repository}}
| programming language = [[Java (programming language)|Java]]
| operating system = [[Cross-platform]]
| genre = [[API]] to access [[Microsoft Office]] [[file format|formats]]
| license = [[Apache License 2.0]]
| website = {{URL|https://poi.apache.org}}
}}
'''Apache POI''', a project run by the [[Apache Software Foundation]], and previously a sub-project of the [[Jakarta Project]], provides pure [[Java platform|Java]] libraries for reading and writing files in [[Microsoft Office]] [[file format|formats]], such as [[Microsoft Word|Word]], [[Microsoft PowerPoint|PowerPoint]] and [[Microsoft Excel|Excel]].

==History and roadmap==
The name was originally an [[acronym]] for "Poor Obfuscation Implementation",<ref name="javaworld2004">{{citation |last1=Sundaram |first1=Elango |date=2004-03-22 |df=dmy |url=https://www.infoworld.com/article/2072333/excelling-in-excel-with-java.html |title=Excelling in Excel with Java |work=[[JavaWorld]] |access-date=2020-07-21}}</ref> referring humorously to the fact that the file formats seemed to be deliberately [[Obfuscated code|obfuscated]], but poorly, since they were successfully [[reverse engineering|reverse-engineered]]. This explanation – and those of the similar names for the various sub-projects – were removed from the official web pages in order to better market the tools to businesses who would not consider such humor appropriate. The original authors ([[Andrew C. Oliver]] and Marc Johnson) also noted the existence of the Hawaiian [[poi (food)|poi]] dish, made of mashed [[taro root]], which had similarly derogatory connotations.<ref>{{citation |url=http://www.coyotesong.com/poi/ |archive-url=https://web.archive.org/web/20041015142404/http://www.coyotesong.com/poi/ |archive-date=2004-10-15 |title=POI homepage from October 2004 |publisher=Coyote Song}}, showing original explanations for naming.</ref>

===Office Open XML support===
POI supports the ISO/IEC 29500:2008 [[Office Open XML]] file formats since version 3.5. A significant contribution for OOXML support came from Sourcesense,<ref>{{citation |url=https://www.sourcesense.com/ |title=SourceSense}}</ref> an [[Open-source software|open source]] company which was commissioned by [[Microsoft]] to develop this contribution.<ref>{{cite web
 |last1=McDougall |first1=Paul
 |date=2008-03-26 |df=dmy
 |url=https://www.informationweek.com/microsoft-eyes-open-source-components-for-office-2007/d/d-id/1066089
 |title=Microsoft Eyes Open Source Components for Office 2007
 |work=[[InformationWeek]]
 |access-date=2020-07-21
}}</ref> This link spurred controversy, some POI contributors questioning POI OOXML patent protection regarding Microsoft's [[Open Specification Promise]] patent license.<ref>{{citation |last1=Oliver |first1=Andrew C. |date=2008-03-27 |df=dmy |url=https://mail-archives.apache.org/mod_mbox/poi-dev/200803.mbox/%3C47EAE71C.6040603@buni.org%3E |title=Rejection of any ENCUMBERED Microsoft Donation to POI |work=POI development mailing list archives |access-date=2020-07-21}}</ref>

==Architecture==
The Apache POI project contains the following subcomponents (meaning of acronyms is taken from old documentation):

* POIFS (Poor Obfuscation Implementation File System<ref name="javaworld2004"/>) – This component reads and writes [[Microsoft]]'s [[OLE 2]] [[COM Structured storage|Compound document]] format.  Since all [[Microsoft Office]] files are [[OLE 2]] files, this component is the basic building block of all the other POI elements. POIFS can therefore be used to read a wider variety of files, beyond those whose explicit decoders are already written in POI.
* HSSF (Horrible SpreadSheet Format<ref name="javaworld2004"/>) – reads and writes [[Microsoft Excel]] (XLS) format files. It can read files written by [[Microsoft Excel|Excel]] 97 onwards; this [[file format]] is known as the ''BIFF 8'' format. As the Excel file format is complex and contains a number of tricky characteristics, some of the more advanced features cannot be read.
* XSSF (XML SpreadSheet Format) – reads and writes [[Office Open XML]] (XLSX) format files.  Similar feature set to HSSF, but for Office Open XML files.
* HPSF (Horrible Property Set Format<ref name="javaworld2004"/>) – reads "Document Summary" information from [[Microsoft Office]] files. This is essentially the information that one can see by using the ''File|Properties'' menu item within an [[Microsoft Office|Office]] application.
* HWPF (Horrible Word Processor Format<ref name="apache1">{{cite web|url=https://poi.apache.org/apidocs/dev/ |title=POI API Documentation |publisher=Poi.apache.org |access-date=2019-03-07}}</ref>) – aims to read and write [[Microsoft Word|Microsoft Word 97]] (DOC) format files. This component is in initial stages of development.
* XWPF (XML Word Processor Format<ref name="apache1"/>) – similar feature set to HWPF, but for Office Open XML files.
* HSLF (Horrible Slide Layout Format<ref name="apache1"/>) – a pure Java implementation for [[Microsoft PowerPoint]] files. This provides the ability to read, create and edit presentations (though some things are easier to do than others)
* XSLF (Open Office XML Slideshow Format)
* HDGF (Horrible DiaGram Format<ref name="apache1"/>) – an initial pure Java implementation for [[Microsoft Visio]] binary files. It provides an ability to read the low level contents of the files.
* HPBF (Horrible PuBlisher Format{{citation needed|date=March 2019}}) – a pure Java implementation for [[Microsoft Publisher]] files.<ref>{{cite web|url=https://poi.apache.org/components/hpbf/index.html |title=POI-HPBF - Java API To Access Microsoft Publisher Format Files |publisher=Poi.apache.org |access-date=2019-03-07}}</ref>
* HSMF (Horrible Stupid Mail Format<ref>{{citation | url = http://npoi.codeplex.com/discussions/233518 | publisher = Microsoft | title = Codeplex NPOI|archive-url=https://web.archive.org/web/20120328092553/http://npoi.codeplex.com/discussions/233518|archive-date=2012-03-28}}</ref>{{Better source needed|date=January 2012|reason=[[WP:CIRCULAR]], as ref in source is this article}}) – a pure Java implementation for [[Microsoft Outlook]] MSG files.<ref>
{{citation | title = POI-HSMF | publisher = Apache | url = http://poi.apache.org/hsmf/ | access-date = 2011-07-31 | archive-url = https://web.archive.org/web/20110807211225/http://poi.apache.org/hsmf/ | archive-date = 2011-08-07 | url-status = dead }}
</ref>
* DDF (Dreadful Drawing Format<ref name="apache1"/>) – a package for decoding the Microsoft Office Drawing format.
* XDDF (XML Dreadful Drawing Format)

The HSSF component is the most advanced feature of the library.<ref>{{citation | url = http://poi.apache.org/hssf/ | title = POI-HSSF | publisher = Apache}}</ref>  Other components (HPSF, HWPF, and HSLF) are usable, but less full-featured.<ref>{{citation | url = http://poi.apache.org/hwpf/ | title = POI-HWPF | publisher = Apache}}</ref><ref>{{citation | url = http://poi.apache.org/hslf/ | title = POI-HSLF | publisher = Apache}}</ref>

The POI library is also provided as a [[Ruby (programming language)|Ruby]]<ref>{{citation | title = POI-Ruby | publisher = Apache | url = http://poi.apache.org/poi-ruby.html}}</ref> or [[ColdFusion]] extension.

There are modules for Big Data platforms (e.g. Apache Hive/Apache Flink/Apache Spark), which provide certain functionality of Apache POI, such as the processing of Excel files.<ref>{{cite web|url=https://github.com/ZuInnoTe/hadoopoffice/wiki |title=HadoopOffice for Hive/Flink/Spark |publisher=Github.com |date=2018-07-19 |access-date=2019-03-07}}</ref><ref>{{cite web|url=https://github.com/crealytics/spark-excel |title=Spark Excel |publisher=Github.com |access-date=2019-03-07}}</ref>

== Version history ==
{{Version|l|show=11101}}

{| class="wikitable"
|- class="hintergrundfarbe5"
! Version number
! Date of release
|-
| {{Version |c |5.3.0}}
| {{dts|2024|7|2}}
|-
| {{Version |o |5.2.0}}
| {{dts|2022|1|14}}
|-
| {{Version |o |5.1.0}}
| {{dts|2021|11|1}}
|-
| {{Version |o |5.0.0}}
| {{dts|2021|1|20}}
|-
| {{Version |o |4.1.0}}
| {{dts|2019|4|9}}
|-
| {{Version |o |4.0.0}}
| {{dts|2018|9|7}}
|-
| {{Version |o |3.17}}
| {{dts|2017|9|15}}
|-
| {{Version |o |3.16}}
| {{dts|2017|4|19}}
|-
| {{Version |o |3.15}}
| {{dts|2016|9|21}}
|-
| {{Version |o |3.14}}
| {{dts|2016|3|2}}
|-
| {{Version |o |3.13}}
| {{dts|2015|9|29}}
|-
| {{Version |o |3.12}}
| {{dts|2015|5|11}}
|-
| {{Version |o |3.11}}
| {{dts|2014|12|21}}
|-
| {{Version |o |3.10}}
| {{dts|2014|2|8}}
|-
| {{Version |o |3.9}}
| {{dts|2012|12|3}}
|-
| {{Version |o |3.8}}
| {{dts|2012|3|26}}
|-
| {{Version |o |3.7}}
| {{dts|2010|10|29}}
|-
| {{Version |o |3.6}}
| {{dts|2009|12|14}}
|-
| {{Version |o |3.5}}
| {{dts|2009|9|28}}
|-
| {{Version |o |3.2}}
| {{dts|2008|10|19}}
|-
| {{Version |o |3.1}}
| {{dts|2008|6|29}}
|-
| {{Version |o |3.0}}
| {{dts|2007|5|18}}
|-
| {{Version |o |2.5}}
| {{dts|2004|2|29}}
|-
| {{Version |o |2.0}}
| {{dts|2004|1|26}}
|-
| {{Version |o |1.5}}
| {{dts|2002|5|6}}
|-
| {{Version |o |1.2.0}}
| {{dts|2002|1|19}}
|-
| {{Version |o |1.1.0}}
| {{dts|2002|1|4}}
|-
| {{Version |o |1.0.0}}
| {{dts|2001|12|30}}
|}

==See also==
*[[Open Packaging Conventions]]
*[[Office Open XML software]]

==References==
{{Reflist|2}}

==External links==
* {{Official website}}

{{Apache Software Foundation}}

{{DEFAULTSORT:Apache Poi}}
[[Category:Apache Software Foundation projects|POI]]
[[Category:Microsoft Office-related software]]
[[Category:Java platform]]
[[Category:Java (programming language) libraries]]
[[Category:Cross-platform free software]]