使用jxl将数据添加到Excel文件

Question

我正在使用jxl创建一个excel文件。首先应该只包含一些关于样式的格式和信息。然后，每当有人向其添加新数据时，都应该更新它。

public class WriteExcel {

    private static WritableWorkbook workbook;
    private static WritableCellFormat timesStandard;
    private String inputFile;
    final private static int FONT_SIZE = 12;


    public void setOutputFile(String inputFile) {
        this.inputFile = inputFile;
    }

    private void prepareSheet(WritableSheet sheet) throws WriteException {
        sheet.mergeCells(0, 0, 1, 0);
        sheet.mergeCells(3, 0, 4, 0);
        sheet.mergeCells(6, 0, 7, 0);

        WritableFont times12pt = new WritableFont(WritableFont.TIMES, FONT_SIZE);
        timesStandard = new WritableCellFormat(times12pt);

        CellView cv = new CellView();
        cv.setFormat(timesStandard);
    }

    public void write() throws IOException, WriteException {
        File file = new File(inputFile);
        WorkbookSettings wbSettings = new WorkbookSettings();
        wbSettings.setLocale(new Locale("en", "EN"));       

        WritableWorkbook workbook = Workbook.createWorkbook(file, wbSettings);
        workbook.createSheet("First", 0); 
        WritableSheet excelSheet = workbook.getSheet(0);
        prepareSheet(excelSheet);

        workbook.write();
        workbook.close();
    }

    public static void main(String[] args) throws WriteException, IOException {
        WriteExcel test = new WriteExcel();
        test.setOutputFile("c:/Users/H/Desktop/test.xls");
        test.write();
    }
}

我知道我需要另一个允许我访问该文件并向其添加一些数据的类：

class Modify {

    private static Logger logger = Logger.getLogger(Modify.class);
    private File inputWorkbook;
    private File outputWorkbook;

    public Modify(String input, String output) {
        inputWorkbook = new File(input);
        outputWorkbook = new File(output);
        logger.info("Input file:  " + input);
        logger.info("Output file:  " + output);
    }

    public void readWrite() throws IOException, BiffException, WriteException {
        logger.info("Reading...");
        Workbook w1 = Workbook.getWorkbook(inputWorkbook);

        logger.info("Copying...");
        WritableWorkbook w2 = Workbook.createWorkbook(outputWorkbook, w1);

        if (inputWorkbook.getName().equals("test.xls")) {
            modify(w2);
        }

        w2.write();
        w2.close();
        logger.info("Done");
    }

    private void modify(WritableWorkbook w) throws WriteException {
        logger.info("Modifying...");

        WritableSheet sheet = w.getSheet("First");

        //createContent(sheet); // contains methods responsible for adding data, for example:
        addNumber(sheet, cols, rows, 2);

    private static void addNumber(WritableSheet sheet, int column, int row, double d) throws WriteException, RowsExceededException {
        Number number;
        number = new Number(column, row, d, timesStandard);
        sheet.addCell(number);

    }
}

但我最终得到一个空白的Excel文件，仅包含合并的单元格。

如何介绍修改？

Answer 1

因为你正在操纵一个WritableWorkbook对象而不是你的类成员为w2，你不应该让你的modify()方法不是无效，而是返回一个WritableWorkbook？

在我看来，当你调用modify()时会实例化一个新的，但是由于范围的原因，最后的所有更改都会被删除。

最后你会得到类似的东西

    private WritableWorkbook modify(WritableWorkbook w) throws WriteException {
    logger.info("Modifying...");

    WritableSheet sheet = w.getSheet("First");

    //createContent(sheet); // contains methods responsible for adding data, for example:
    addNumber(sheet, cols, rows, 2);
    return sheet;
    }

基本上。对addNumber的类似修改似乎也是如此。然后各自的电话将是sheet = addNumber(sheet, cols, rows, 2);和w2 = modify(w2);