Thanks for the link
No sooner said than done 
If someone has the same problem here is the class I added, which additionally adds borders around each cell:
public class CustomisedHSSFExcelExporter extends HSSFExcelExporter {
@Override
public final void exportEnd(final OutputStream outputStream) throws IOException {
if (this.xlSheet.getRow(0) != null) {
for (int r = 0; r < this.xlSheet.getPhysicalNumberOfRows(); r++) {
Row row = this.xlSheet.getRow(r);
for (int c = 0; c < row.getPhysicalNumberOfCells(); c++) {
Cell cell = row.getCell(c);
if (cell != null) {
CellStyle style = cell.getCellStyle();
// add a border around each cell
style.setBorderBottom(CellStyle.BORDER_THIN);
style.setBottomBorderColor(IndexedColors.GREY_40_PERCENT.getIndex());
style.setBorderLeft(CellStyle.BORDER_THIN);
style.setLeftBorderColor(IndexedColors.GREY_40_PERCENT.getIndex());
style.setBorderRight(CellStyle.BORDER_THIN);
style.setRightBorderColor(IndexedColors.GREY_40_PERCENT.getIndex());
style.setBorderTop(CellStyle.BORDER_THIN);
style.setTopBorderColor(IndexedColors.GREY_40_PERCENT.getIndex());
}
}
}
int numberOfColumns = this.xlSheet.getRow(0).getPhysicalNumberOfCells();
for (int i = 0; i < numberOfColumns; i++) {
// auto-resize each cell according to its current content
this.xlSheet.autoSizeColumn(i);
}
}
super.exportEnd(outputStream);
}
}
[Updated on: Tue, 10 February 2015 16:40] by Moderator