When getting cell content using Apache-POI Library

问题:

I realize the question is a little confusing, but I didn't know how else to word it. Anyway, here is the original code:

private void readFile(String excelFileName) throws FileNotFoundException, IOException {
    XSSFWorkbook workbook = new XSSFWorkbook(new FileInputStream(excelFileName));
    if (workbook.getNumberOfSheets() > 1){
        System.out.println("Please make sure there is only one sheet in the excel workbook.");
    }
    XSSFSheet sheet = workbook.getSheetAt(0);
    int numOfPhysRows = sheet.getPhysicalNumberOfRows();
    XSSFRow row;
    XSSFCell num;
    for(int y = 1;y < numOfPhysRows;y++){    //start at the 2nd row since 1st should be category names
        row = sheet.getRow(y);
        poNum = row.getCell(1);
        item = new Item(Integer.parseInt(poNum.getStringCellValue());
        itemList.add(item);
        y++;
    }
}

private int poiConvertFromStringtoInt(XSSFCell cell){
    int x = Integer.parseInt(Double.toString(cell.getNumericCellValue()));
    return x;
}

I am getting the following error:

Exception in thread "main" java.lang.IllegalStateException: Cannot get a numeric value from a text cell
    at org.apache.poi.xssf.usermodel.XSSFCell.typeMismatch(XSSFCell.java:781)
    at org.apache.poi.xssf.usermodel.XSSFCell.getNumericCellValue(XSSFCell.java:199)

Even if I change it to get either a string using XSSFCell.getStringCellValue() or even XFFSCell.getRichTextValue, I get the reverse of the above error message (and I am making sure to ultimately make it an int using Integer.parseInt(XSSFCell.getStringCellValue()).

The error then reads:

Exception in thread "main" java.lang.IllegalStateException: Cannot get a text value from a numeric cell
    at org.apache.poi.xssf.usermodel.XSSFCell.typeMismatch(XSSFCell.java:781)
    at org.apache.poi.xssf.usermodel.XSSFCell.getNumericCellValue(XSSFCell.java:199)

I know for a fact that the excel spreadsheet column is in fact a string. I can't change the excel sheet as it is uploaded else where always using the same format and formatting each column first takes up to much processing time.

Any suggestions?

[Solution] Here is the solution code I came up with from @Wivani's help:

private long poiGetCellValue(XSSFCell cell){
    long x;
    if(cell.getCellType() == 0)
        x = (long)cell.getNumericCellValue();
    else if(cell.getCellType() == 1)
        x = Long.parseLong(cell.getStringCellValue());
    else
        x = -1;
    return x;
}

回答1:

Use This as reference

switch (cell.getCellType()) {
                case Cell.CELL_TYPE_STRING:
                    System.out.println(cell.getRichStringCellValue().getString());
                    break;
                case Cell.CELL_TYPE_NUMERIC:
                    if (DateUtil.isCellDateFormatted(cell)) {
                        System.out.println(cell.getDateCellValue());
                    } else {
                        System.out.println(cell.getNumericCellValue());
                    }
                    break;
                case Cell.CELL_TYPE_BOOLEAN:
                    System.out.println(cell.getBooleanCellValue());
                    break;
                case Cell.CELL_TYPE_FORMULA:
                    System.out.println(cell.getCellFormula());
                    break;
                default:
                    System.out.println();
            }

回答2:

You can get value as String using the format defined for this cell :

final DataFormatter df = new DataFormatter();
final XSSFCell cell = row.getCell(cellIndex);
String valueAsString = df.formatCellValue(cell);

Thanks to this answer.

回答3:

Just use cell.setCellType(1); before reading cell value and get it as String always, after that you can use it in your own format(type).

Ravi

回答4:

Use the below code to read any data type from xcels using poi.

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.util.Iterator;
import org.apache.poi.ss.usermodel.Cell;
import org.apache.poi.ss.usermodel.DataFormatter;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.xssf.usermodel.XSSFSheet;
import org.apache.poi.xssf.usermodel.XSSFWorkbook;

/**
 *
 * @author nirmal
 */
public class ReadWriteExcel {

    public static void main(String ar[]) {
        ReadWriteExcel rw = new ReadWriteExcel();
        rw.readDataFromExcel();

    }
    Object[][] data = null;

    public File getFile() throws FileNotFoundException {
        File here = new File("test/com/javaant/ssg/tests/test/data.xlsx");
        return new File(here.getAbsolutePath());

    }

    public Object[][] readDataFromExcel() {
        final DataFormatter df = new DataFormatter();
        try {

            FileInputStream file = new FileInputStream(getFile());
            //Create Workbook instance holding reference to .xlsx file
            XSSFWorkbook workbook = new XSSFWorkbook(file);

            //Get first/desired sheet from the workbook
            XSSFSheet sheet = workbook.getSheetAt(0);

            //Iterate through each rows one by one
            Iterator<Row> rowIterator = sheet.iterator();

            int rownum = 0;
            int colnum = 0;
            Row r=rowIterator.next();

            int rowcount=sheet.getLastRowNum();
            int colcount=r.getPhysicalNumberOfCells();
            data = new Object[rowcount][colcount];
            while (rowIterator.hasNext()) {
                Row row = rowIterator.next();

                //For each row, iterate through all the columns
                Iterator<Cell> cellIterator = row.cellIterator();
                colnum = 0;
                while (cellIterator.hasNext()) {

                    Cell cell = cellIterator.next();
                    //Check the cell type and format accordingly
                    data[rownum][colnum] =  df.formatCellValue(cell);
                    System.out.print(df.formatCellValue(cell));
                    colnum++;
                    System.out.println("-");
                }
                rownum++;
                System.out.println("");
            }
            file.close();
        } catch (Exception e) {
            e.printStackTrace();
        }

        return data;
    }
}

回答5:

I got also this bug with POI version 3.12final.
I think that the bug is registered there : https://bz.apache.org/bugzilla/show_bug.cgi?id=56702 and I put a comment there with my analysis.

Here is the workaround I used : The exception was risen by HSSFCell.getNumericCellValue which was called by DateUtil.isCellDateFormatted. DateUtil.isCellDateFormatted does 2 things :
1) check the value type of the cell by calling HSSFCell.getNumericCellValue and then DateUtil.isValidExcelDate(), which is almost pointless here I think.
2) check if the format of the cell is a date format

I copied the code of topic 2) above in a new function 'myIsADateFormat' and used it instead of DateUtil.isCellDateFormatted (that is quite dirty to copy library code, but it works...) :

private boolean myIsADateFormat(Cell cell){
    CellStyle style = cell.getCellStyle();
    if(style == null) return false;
    int formatNo = style.getDataFormat();
    String formatString = style.getDataFormatString();
    boolean result = DateUtil.isADateFormat(formatNo, formatString);
    return result;
}

If you need to check the value type first, you can use this too :

CellValue cellValue = evaluator.evaluate(cell);
int cellValueType = cellValue.getCellType();
if(cellValueType == Cell.CELL_TYPE_NUMERIC){
    if(myIsADateFormat(cell){
        ....
    }
}

回答6:

Documentation clearly says not to setCellType to 1 instead use the DataFormatter like how Thierry has explained:

https://poi.apache.org/apidocs/org/apache/poi/ss/usermodel/Cell.html#setCellType(int)

回答7:

Ravi's solution works : Just use cell.setCellType(1); before reading cell value and get it as String always, after that you can use it in your own format(type).