How to read Excel cell having null values too in Java…?

问题

I'm using Apache POI 3.6. I've a column which is blank. I would like to be able to read it and then move to the next column. Even if I could resolve the NullPointerException problem I could not get to the next cell.

Here's my code snippet :

HSSFCell cell = row.getCell(c);
String value = null;

switch (cell.getCellType()) {

    case HSSFCell.CELL_TYPE_FORMULA:
        value = "FORMULA value=" + cell.getCellFormula();
        break;

    case HSSFCell.CELL_TYPE_NUMERIC:
        value = "NUMERIC value=" + cell.getNumericCellValue();
        break;

    case HSSFCell.CELL_TYPE_STRING:
        value = "STRING value=" + cell.getStringCellValue();
        break;

    case HSSFCell.CELL_TYPE_BLANK:
        value="";
        break;

    case HSSFCell.CELL_TYPE_ERROR:
        value="error";
        break;

    default:
        break;
}

System.out.println("CELL col=" + cell.getColumnIndex() + " VALUE=" + value);

How can I resolve my problem?

回答1:

Well, you could check for null before your switch statement, or you could change which call to row.getCell you make. Checking the Javadoc for POI there are 2 forms, the first is what you are using, the second has an additional parameter, of the type Row.MissingCellPolicy, where you can pass a value that would automagically transform null cells into blanks.

回答2:

I've finally got what I want. I thank mezmo for it. I want to share the exact code snippet to be changed. Just replace the line having :

HSSFCell cell = row.getCell(c);

with

HSSFCell cell=row.getCell(c, org.apache.poi.ss.usermodel.Row.CREATE_NULL_AS_BLANK );

回答3:

You need to check if cell!=null, because if a cell doesn't exist in a row, row.getCell(c) returns null

回答4:

Try this

List cellDataList = new ArrayList();
XSSFWorkbook workbook = new XSSFWorkbook(fileInputStream);

                        XSSFSheet sheet = workbook.getSheetAt(0);

                        Iterator rows = sheet.rowIterator();

                        int number=sheet.getLastRowNum();


                        int lineNumber = 0;

                        while (rows.hasNext())

                        {
                            XSSFRow row = ((XSSFRow) rows.next());
                            lineNumber++;
                            if(lineNumber==1){continue;}




                            Iterator cells = row.cellIterator();
                            List cellTempList = new ArrayList();    
                            int current = 0, next =1;
                            while(cells.hasNext())

                            {

                                XSSFCell cell = (XSSFCell) cells.next();


                                current = cell.getColumnIndex();


                                if(current<next){

                                }
                                else{

                                    int loop = current-next;

                                    for(int k=0;k<loop+1;k++){

                                        cellTempList.add(null);
                                        next = next + 1;
                                    }
                                }
                                switch (cell.getCellType()) {
                                            case Cell.CELL_TYPE_STRING:
                                                System.out.println(cell.getRichStringCellValue().getString());
                                                cellTempList.add(cell.getRichStringCellValue().getString());
                                                break;
                                            case Cell.CELL_TYPE_NUMERIC:                                                    
                                                    System.out.println(cell.getNumericCellValue());
                                                    cellTempList.add(String.valueOf(cell.getNumericCellValue()));                                                   
                                                break;
                                            case Cell.CELL_TYPE_BOOLEAN:
                                                System.out.println(cell.getBooleanCellValue());
                                                break;
                                            case Cell.CELL_TYPE_FORMULA:
                                                System.out.println(cell.getCellFormula());
                                                cellTempList.add(cell.getCellFormula());
                                                break;                                              

                                            default:
                                                System.out.println("Inside default");
                                }
                                next = next + 1;

                            }
                            cellDataList.add(cellTempList); 
                         }

回答5:

Thank you Venkat, it work for me also except
for those who are using Apache 4.0.0 and up they need to do it as :

HSSFCell cell=row.getCell(c, org.apache.poi.ss.usermodel.Row.MissingCellPolicy.CREATE_NULL_AS_BLANK);

来源：https://stackoverflow.com/questions/3132732/how-to-read-excel-cell-having-null-values-too-in-java