How deal with blank cells in excel files java

Question

I am making a program where I am reading data from excel files and store them in tables. I have made the program using Apache POI and works fine. But when files have blank c

Answer 1

            int maxNumOfCells = sheet.getRow(0).getLastCellNum(); // The the maximum number of columns
            Iterator rows = sheet.rowIterator();
            while (rows.hasNext()) {
                HSSFRow row = (HSSFRow) rows.next();
                Iterator cells = row.cellIterator();

                List data = new ArrayList();
                for( int cellCounter = 0
                        ; cellCounter < maxNumOfCells
                        ; cellCounter ++){ // Loop through cells

                    HSSFCell cell;

                    if( row.getCell(cellCounter ) == null ){
                        cell = row.createCell(cellCounter);
                    } else {
                        cell = row.getCell(cellCounter);
                    }

                    data.add(cell);

                }

                sheetData.add(data);

YOUR METHOD:

public static void showExcelData(List sheetData) {

        // LinkedHashMap tableFields = new LinkedHashMap();
        for (int i = 0; i < sheetData.size(); i++) {
            List list = (List) sheetData.get(i);
            for (int j = 0; j < list.size(); j++) {
                Cell cell = (Cell) list.get(j);
                if (cell.getCellType() == Cell.CELL_TYPE_NUMERIC) {
                    System.out.print(cell.getNumericCellValue());
                } else if (cell.getCellType() == Cell.CELL_TYPE_STRING) {
                    System.out.print(cell.getRichStringCellValue());
                } else if (cell.getCellType() == Cell.CELL_TYPE_BOOLEAN) {
                    System.out.print(cell.getBooleanCellValue());
                } else if (cell.getCellType() == Cell.CELL_TYPE_BLANK) {
                    System.out.print("THIS IS BLANK");
                }
                if (j < list.size() - 1) {
                    System.out.print(", ");
                }
            }
            System.out.println("");
        }

    }

Explanation:

int maxNumOfCells = sheet.getRow(0).getLastCellNum(); - This line will make sure that you were able to get the number of columns. Using the Row's method .getLastCellNum() on the next rows will result to unexpected number. Example on your on row 3 of your spreadsheet, the method will return 2 since the next value is null.

            for( int cellCounter = 0
                    ; cellCounter < maxNumOfCells
                    ; cellCounter ++){ // Loop through cells

                HSSFCell cell;

                if( row.getCell(cellCounter ) == null ){
                    cell = row.createCell(cellCounter);
                } else {
                    cell = row.getCell(cellCounter);
                }

                data.add(cell);

            }

Looping through the cells. From cell 0 (Base 0) to the last cell number. If the cell was found null, basically, it would create the cell with a blank value. Lastly, adding the cell to your List.