Quick introduction to Apache POI

This chapter highlights some of the core APIs we will end up using in this tutorial.

Workbook

The org.apache.poi.ss.usermodel package contains base interface called Workbook of all classes that is used to create and maintain Excel.

The two classes for this interface are as follows:

• XSSFWorkbook: This is Compatible with versions 2007 of MSOffice or later.It contains methods to write and read OpenOffice xml and Excel files in .xlsx and .xlx format.

  You can read the complete list of constructors and methods available on the API page from the link below

  http://poi.apache.org/apidocs/org/apache/poi/xssf/usermodel/XSSFWorkbook.html

• HSSFWorkbook: This is compatible with Version 97 -2003 of MS office. It contains methods to write and read Microsoft Excel files.
  

  You can read the complete list of constructors and methods available on the API page from the link below

  http://poi.apache.org/apidocs/org/apache/poi/hssf/usermodel/HSSFWorkbook.html

WorkbookUtil

This class have quite a few helper methods for when working with Usermodel Workbooks. 

More on API can be read from the link below

http://poi.apache.org/apidocs/org/apache/poi/ss/util/WorkbookUtil.html 

Row Interface 

This interface is a high level representation of a row of a spreadsheet.

More on API can be read from the link below

http://poi.apache.org/apidocs/org/apache/poi/ss/usermodel/Row.html

Cell Interface

Cell is a high level representation of a cell in a row of a spreadsheet.

Cells can be numeric, formula-based or general text and is specified by a cell type. Key things to note are

• String cells cannot contain numbers.
• Numeric cells cannot contain strings.
• Our client program will handle the conversions where applicable.
• Formula cells have the formula string along with the formula result, which can be numeric or text value.

Cells should have their index specified which is 0 based, before being added to a row.

More on cell interface can be read from the link below

http://poi.apache.org/apidocs/org/apache/poi/ss/usermodel/Cell.html

There are numrous other API classes which we will not cover in this quick introduction tutorial

However, Details on current version of Apache POI API can be found here