I have used both JXL (now "JExcel") and Apache POI. At first I used JXL, but now I use Apache POI.
First, here are the things where both APIs have the same end functionality:
- Both are free
- Cell styling: alignment, backgrounds (colors and patterns), borders (types and colors), font support (font names, colors, size, bold, italic, strikeout, underline)
- Merged cell regions
- Size of rows and columns
- Data formatting: Numbers and Dates
- Text wrapping within cells
- Freeze Panes
- Header/Footer support
- Read/Write existing and new spreadsheets
- Both attempt to keep existing objects in spreadsheets they read in intact as far as possible.
However, there are many differences:
- Perhaps the most significant difference is that Java JXL does not support the Excel 2007+ ".xlsx" format; it only supports the old BIFF (binary) ".xls" format. Apache POI supports both with a common design.
- Additionally, the Java portion of the JXL API was last updated in 2009 (3 years, 4 months ago as I write this), although it looks like there is a C# API. Apache POI is actively maintained.
- JXL doesn't support Conditional Formatting, Apache POI does, although this is not that significant, because you can conditionally format cells with your own code.
- JXL doesn't support rich text formatting, i.e. different formatting within a text string; Apache POI does support it.
- JXL only supports certain text rotations: horizontal/vertical, +/- 45 degrees, and stacked; Apache POI supports any integer number of degrees plus stacked.
- JXL doesn't support drawing shapes; Apache POI does.
- JXL supports most Page Setup settings such as Landscape/Portrait, Margins, Paper size, and Zoom. Apache POI supports all of that plus Repeating Rows and Columns.
- JXL doesn't support Split Panes; Apache POI does.
- JXL doesn't support Chart creation or manipulation; that support isn't there yet in Apache POI, but an API is slowly starting to form.
- Apache POI has a more extensive set of documentation and examples available than JXL.
Additionally, POI contains not just the main "usermodel" API, but also an event-based API if all you want to do is read the spreadsheet content.
In conclusion, because of the better documentation, more features, active development, and Excel 2007+ format support, I use Apache POI.