Jakarta Poi

Packages

org.apache.poi.hpsf	Horrible PropertySet Format API reads things like Document Summary info from OLE 2 Compound document files.
org.apache.poi.hpsf.littleendian	Handles reading little endian data for HPSF
org.apache.poi.hpsf.wellknown	Specific support for DocumentSummaryInformation, SummaryInformation types.
org.apache.poi.hssf	Horrible SpreadSheet Format API's for reading/writting Excel files using pure Java.
org.apache.poi.hssf.dev	DEV package serves two purposes.
org.apache.poi.hssf.eventmodel	HSSF eventmodel Package provides an event-based API for reading HSSF files.
org.apache.poi.hssf.model	Provides low level API structures for reading, writing, modifying XLS files.
org.apache.poi.hssf.record	Record package contains class representations for XLS binary strutures.
org.apache.poi.hssf.record.aggregates	record aggregates are not real "records" but collections of records that act as a single record.
org.apache.poi.hssf.record.formula	formula package contains binary PTG structures used in Formulas (not yet supported!)
org.apache.poi.hssf.usermodel	usermodel package maps HSSF low level strutures to familiar workbook/sheet model
org.apache.poi.hssf.util	util package contains tools needed for writing HSSF files that are not necesarily "real" HSSF concepts.
org.apache.poi.poifs.common	common package contains constants and other classes shared across all POIFS subpackages
org.apache.poi.poifs.dev	DEV package serves two purposes.
org.apache.poi.poifs.eventfilesystem	The eventfilesystem is an efficient method for reading OLE 2 CDF files.
org.apache.poi.poifs.filesystem	filesystem package maps OLE 2 Compound document files to a more familiar filesystem interface.
org.apache.poi.poifs.property	property package contains high and low level Property structures for POIFS.
org.apache.poi.poifs.storage	storage package contains low level binary structures for POIFS's implementation of the OLE 2 Compound Document Format.
org.apache.poi.util	Top-level util package are classes that are useful throughout the project.