Look at the following table for the list of Jxcell features:

Unicode support
CSV files (delimited with comma, tab, semicolon or any other separator)  
Excel97-2003(xls),Excel2007-2013(xlsx) format supports  
Encrypted and Decrypted Excel files(xls,xlsx files)  
Multiple worksheets per file
Template support (create new workbooks using existing workbook as a template)
Various cell data types (numbers, strings,dates, floating point etc.)
Custom number formatting
Merged regions
Cell styles (alignment, indentation, rotation, borders, shading, protection, text wrapping and shrinking etc.)
Font formatting (size, color, font type, italic and strikeout properties, different levels of boldness, underlining, subscript and superscript)
formatting options(font,color,content format,pattern,border line,border color,align).
Conditional Formats (Apply cell formats when the value of a cell or formula meets a predetermined set of conditions..) ConditionFormat.java output conditionformats.xls
Text orientation and Applying different formatting to parts of a cell TextFormatting.java output textformatting.xls
Data Validation datavalidation.java output datavalidation.xls
Copy/Move/Delete (Cells can be copied, moved and deleted with the same behaviour as in Excel. Rows and columns can be copied and moved as well.Copy/move between sheets are supported. Entire sheets can be copied.) RangeCopy.java
Row height and column width
Formula support (absolute and relative references, names, 3D cell references, more than 260 supported functions)


output  formula.xls
Named ranges(Names can be used where you want.Access cells through their name is easy)
Calculation Engine(Cells and whole worksheets can be calculated)  
Formulas with referrences to external workbooks are supported as well.  
Charts(Supports all standard Chart Types like Column, Bar, Line, Pie, Scatter etc)   input book.csv  output barChart.xls columnChart.xls lineChart.xls pieChart.xls areaChart.xls
Customize Charts (stack chart,percent Pie chart data lable,chart format set etc) ChartSample.java
Pictures support (BMP, JPG, GIF, PNG, WMF) PicTest.java
Hyperlink support(cell link,url link,email link,file link) Hyperlinks.java hyperlink.xls
Export data to(Excel files,CSV text files,HTML fils.)
Convert Excel to Pdf file PdfPrint.java PdfPrint.zip(1528k)
Access all printing options (Select paper size, set margins. Set header and footer, including formatting codes. Define printing areas. Set page breaks. Preserving print area and summaries)
Spreadsheet Designer.
View,Create,Modify,Print spreadsheet in Swing gui Component.
Java spreadsheet Applet  
supports VBA and macros(Copy from template).