Import an excel file, solve the problem of skipping blank cells without reading and moving the subscript forward, and return_ BLANK_ AS_ Null red

 

Problem description ： In the use of Poi Import Excel When you file , Like the first line   After reading That's ok Traverse after data Column When the license plate number of the trailer is empty during data processing , No data was read from this cell , Because this cell is spatiotemporal , Therefore, the subscript of the data in the next column is moved forward by one , As a result, the field name and content cannot be matched , Some fields in the business have regular judgments , So blank cells must also be read out and assigned blank values , In this way, the fields and contents can be matched one by one , Regular can also pass smoothly .

Here is the main code

First look at the code before the modification ,

    Workbook workbook = null;
        List<List<Object>> lists = new ArrayList<>();
        workbook = new HSSFWorkbook(inputStream);
        // Get the first Sheet page 
        Sheet sheet = workbook.getSheetAt(0);
        // An iterator method to get rows 
        Iterator<Row> rowIterator = sheet.rowIterator();
        while (rowIterator.hasNext()) {
            ArrayList<Object> rowData = new ArrayList<>();
            Row row = rowIterator.next();
            // Get each column in each row 
            Iterator<Cell> cellIterator = row.cellIterator();
            while (cellIterator.hasNext()) {
                Cell cell = cellIterator.next();
                if (cell == null || cell.getCellType().equals(CellType.BLANK)) {
                    cell.setCellValue("");
                }
                Object user = getCellData(cell, workbook);
                rowData.add(user);
            }
            lists.add(rowData);
        }
        workbook.close();
        return lists;
    }

Modified code ,

        Workbook workbook = null;
        List<List<Object>> lists = new ArrayList<>();
        workbook = new HSSFWorkbook(inputStream);
        // Get the first Sheet page 
        Sheet sheet = workbook.getSheetAt(0);
//        // An iterator method to get rows 
        Iterator<Row> rowIterator = sheet.rowIterator();
        while (rowIterator.hasNext()) {
            ArrayList<Object> rowData = new ArrayList<>();
            Row row = rowIterator.next();
            // Get each column in each row 
            Iterator<Cell> cellIterator = row.cellIterator();
            // Count . Control jumps out of the loop . Loop read column 
            int i = -1;
            // Get the number of columns per row 
            short lastCellNum = row.getLastCellNum();
            while (cellIterator.hasNext()) {
                i++;
                // Can read empty cells normally 
                Cell cell = row.getCell(i, Row.MissingCellPolicy.CREATE_NULL_AS_BLANK);
                if (i == lastCellNum) {
                    break;
                }
                if (cell == null || cell.getCellType().equals(CellType.BLANK)) {
                    cell.setCellValue("");
                }
                Object user = getCellData(cell, workbook);
                rowData.add(user);
            }
            lists.add(rowData);
        }
        workbook.close();
        return lists;
    }

The above is the solution code .

In solving this problem , Thinking about POI Find it on the official website We will see such a solution later

// Decide which rows to process

int rowStart = Math.min(15, sheet.getFirstRowNum());


int rowEnd = Math.max(1400, sheet.getLastRowNum());

for (int rowNum = rowStart; rowNum < rowEnd; rowNum++) {

   Row r = sheet.getRow(rowNum);

   if (r == null) {

      // This whole row is empty

      // Handle it as needed

      continue;
   }

   int lastColumn = Math.max(r.getLastCellNum(), MY_MINIMUM_COLUMN_COUNT);


   for (int cn = 0; cn < lastColumn; cn++) {

      Cell c = r.getCell(cn, Row.RETURN_BLANK_AS_NULL);

      if (c == null) {

         // The spreadsheet is empty in this cell

      } else {

         // Do something useful with the cell's contents

      }

   }

}

  I don't use it because I don't want to change the code I wrote before , So I didn't write it , But see this code ：

Cell c = r.getCell(cn, Row.RETURN_BLANK_AS_NULL);

All of a sudden there was inspiration , You can transplant this code into my code , How RETURN_BLANK_AS_NULL Keep reporting red , Do you know that ？

So I have this code

   Cell cell = row.getCell(i, Row.MissingCellPolicy.CREATE_NULL_AS_BLANK);

It's a good solution to this problem .

So far, the problem has been basically solved ！