Exception inside getCellFormula() occours when try to do this: cell.setCellFormula(row.getCell().getCellFormula()); (cell, row and row.getCell() are not null !) This happens also in new POI 2.0 RC1
Its impossible to debug, unless the code is compilable, you attach the workbook on which the error occurs, and the actual exception. How is anybody supposed to figure out what is wrong if even the Stacktrace is missing?
I'm sorry, but this is impossible to debug. I can see lots of cases where cell.setCellFormula(row.getCell().getCellFormula()); works perfectly. You need to provide your case where it doesnt work.