Setting filter on headers of an Excel sheet via POI

Question

Save the first and last cell from filter area, and execute:

sheet.setAutoFilter(new CellRangeAddress(firstCell.getRow(), lastCell.getRow(), firstCell.getCol(), lastCell.getCol()));

For example, from the below sheet.

>x         (x, y)
  0123456  
0|--hhh--|   h = header
1|--+++--|   + = values
2|--+++--|   - = empty fields
3|--+++--|
4|-------|

first cell will be the header above the first + (2,1) cell. The last will be the last + cell (5,3)