POI, a sub-project of the Apache Software Foundation Jakarta Project, provides pure Java platform libraries for reading and writing files in Microsoft Office file format, such as Microsoft Word and Microsoft Excel.
The name was originally an acronym for Poor Obfuscation Implementation , referring humourously to the fact that the file formats seemed to be deliberately obfuscation, but poorly, since they were successfully reverse engineering. This expansion - 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 humour appropriate.
The Apache Jakarta POI project contains the following subcomponents:
POIFS (Poor Obfuscation Implementation File System) - This component reads and writes Microsoft s OLE 2 Compound Documentation 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) - reads and writes Microsoft Excel (XLS) format files. It can read files written by Microsoft Excel 97 onwards. This file format is known as the BIFF 8 format.
HPSF (Horrible Property Set Format) - 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 application.
HWPF (Horrible Word Processor Format) - aims to read and write Microsoft Word (DOC) format files. This component is in initial stages of development.
= External link =
[http://jakarta.apache.org/poi Jakarta POI] - the official page at the Apache Jakarta Project