Java Excel API is a mature, open source java API enabling developers to read, write, and modifiy Excel spreadsheets dynamically. Now java developers can read Excel spreadsheets, modify them with a convenient and simple API, and write the changes to any output stream (e.g. disk, HTTP, database, or any socket).

Some Features

• Reads data from Excel 95, 97, 2000, XP, and 2003 workbooks
• Reads and writes formulas (Excel 97 and later only)
• Generates spreadsheets in Excel 2000 format
• Supports font, number and date formatting
• Supports shading, bordering, and coloring of cells
• Modifies existing worksheets
• Is internationalized, enabling processing in almost any locale, country, language, or character encoding (formulas are currently only supported in English, French, Spanish, and German, but more can be added if translated)
• Supports copying of charts
• Supports insertion and copying of images into spreadsheets
• Supports logging with Jakarta Commons Logging, log4j, JDK 1.4 Logger, etc

The POI project consists of APIs for manipulating various file formats based upon Microsoft's OLE 2 Compound Document format using pure Java. In short, you can read and write MS Excel files using Java. Soon, you'll be able to read and write Word, PowerPoint and Visio files using Java. POI is your Java Excel solution as well as your Java Word solution. However, we have a complete API for porting other OLE 2 Compound Document formats, and welcome others to participate.

OLE 2 Compound Document Format based files include most Microsoft Office files such as XLS and DOC as well as MFC serialization API based file formats.

At this time, none of our releases support the new Office Open XML file formats, such as .xlsx or .docx. Work to support these is in progress, and people interested should follow the dev list. We expect this support to make it into a full release by the summer.