Workbook workbook = new Workbook(dataDir + "Book1.xlsx");
Cells cells = workbook.getWorksheets().get(0).getCells();
Cell cell = cells.get("B2");

//Tracing precedents of the cell A12.
//The return array contains ranges and cells.
ReferredAreaCollection ret = cell.getPrecedents();

//Printing all the precedent cells' name.
if(ret != null)
{
    for(int m = 0 ; m < ret.getCount(); m++)
    {
        ReferredArea area = ret.get(m);
        StringBuilder stringBuilder = new StringBuilder();
        if (area.isExternalLink())
        {
            stringBuilder.append("[");
            stringBuilder.append(area.getExternalFileName());
            stringBuilder.append("]");
        }
        stringBuilder.append(area.getSheetName());
        stringBuilder.append("!");
        stringBuilder.append(CellsHelper.cellIndexToName(area.getStartRow(), area.getStartColumn()));
        if (area.isArea())
        {
            stringBuilder.append(":");
            stringBuilder.append(CellsHelper.cellIndexToName(area.getEndRow(), area.getEndColumn()));
        }
        System.out.println("Tracing Precedents: " + stringBuilder.toString());
    }
}