Clients of Apache POI API are index builders, content management system, web spiders and many other text extraction applications. Apache POI is used by these applications excessively so that to do the manipulation of their operations.
Question arises that why one shall use POIFS, XSSF and HSSF?
Answers to these questions are as following. You can use POIFS in case your documents have been written in format OLE2. It makes you read the documents that
Apache POI project consist of the following components. Poor Obfuscation Implementation File System (POIFS): It is involved in writing and reading the format of the MS OLE 2 Compound document. All MS Office files are basically OLE files and this component is POI elementís basic building block. POIFS assist to read variety of files.Horrible SpreadSheet Format (HSSF): Microsoft Excel (XLS) format file are read and written by it. Files could be read by it which is being written
Apache POI is apache project which provides the access of MS format files to Java APIs. POI means Poor Obfuscation Implementation. It is a great API for MS document format access. Java programmers find it to be a best solution. APIs are present in POI to manipulate different formats of files which are based at the MS OLE 2 Compound Document, using pure Java. By using Java, you can write/read MS Excel files. A spreadsheet could also be created through Cocoon serializer.
HSSF is the pure Java