Bug 361443 Excel ODA
data/org.eclipse.birt.report.data.oda.excel/src/org/eclipse/birt/report/data/oda/excel/impl/util/ExcelFileReader.java
xlsIs.close();
				}
				if ( xlsxIs != null)
				{
					xlsxIs.close();
				}
			} catch (IOException e) {
				
				e.printStackTrace();
			}
		}
		return ExcelODAConstants.UNSUPPORT_FORMAT;
	}
	public String getCellValue(Cell cell) {
		if (cell == null)
			return ExcelODAConstants.EMPTY_STRING;
		if (cell.getCellType() == Cell.CELL_TYPE_FORMULA) {
			return resolveFormula(cell);
		}
		if (cell.getCellType() == Cell.CELL_TYPE_NUMERIC) {
			if (org.apache.poi.ss.usermodel.DateUtil.isCellDateFormatted(cell)) {
				Date myjavadate = org.apache.poi.ss.usermodel.DateUtil.getJavaDate(cell.getNumericCellValue());
				long millis = myjavadate.getTime();
				return Long.toString(millis);
			}
			return ((Double) cell.getNumericCellValue()).toString();
		}
		return cell.toString();
	}
	private String resolveFormula(Cell cell) {