Question

我无法使用jxl编辑现有的Excel工作表。它总是创造一个新的。任何人都可以帮我解决它。请提供一个小样本代码。

Answer 1

jxl旨在提高读取效率（因为这是API的主要用途）。为了提高性能，在读取电子表格时不会解释与输出信息相关的数据（例如，所有格式信息，如字体），因为在查询原始数据值时这是多余的。

但是，如果我们需要修改此电子表格，则需要使用各种写入接口的句柄，这可以使用复制方法获得。

Workbook workbook = Workbook.getWorkbook(new File("myfile.xls"));
WritableWorkbook copy = Workbook.createWorkbook(new File("temp.xls"), workbook);

这将复制已读入的信息，并执行其他处理以解释编写电子表格所必需的字段。这种读优化策略的缺点是我们在内存中保存了两个电子表而不是一个，从而使内存需求翻倍。

但在此之后，你可以做任何你想做的事。像：

WritableSheet sheet2 = copy.getSheet(1); 
WritableCell cell = sheet2.getWritableCell(1, 2); 

if (cell.getType() == CellType.LABEL) 
{ 
  Label l = (Label) cell; 
  l.setString("modified cell"); 
}
copy.write(); 
copy.close();
workbook.close();

注意：这直接来自Andy Khan's tutorial page。

Answer 2

我知道这是一个很老的问题，但如果有人会遇到同样的问题，那么保留正确的格式（字体类型，着色等）您应该在将单元格格式转换为Label之前保存单元格格式，然后强制单元格进行上一格式化。代码：

CellFormat cfm = cell.getCellFormat();
Label l = (Label) cell; 
l.setString("modified cell");
cell.setCellFormat(cfm);

Answer 3

//there is god example of it, you can copy in ur project and check it out, to 
//understand how  it works

Workbook wk = Workbook.getWorkbook(new File("ex.xls"));
// 
WritableWorkbook wkr = Workbook.createWorkbook(new File("modifed.xls"), wk);
/* second line makes copy of wk excel file object /creates a readable spreadsheet.
both are now similar and i can Modify exiting wkr spreadsheets */



 //next 2 line retrieve sheet number 0  and cell (1,1)


 WritableSheet getsht = wkr.getSheet(0);
 WritableCell getcl = getsht.getWritableCell(1, 1);


 //making own font 

WritableFont ft = new WritableFont(WritableFont.ARIAL, 20 , WritableFont.BOLD, true , UnderlineStyle.SINGLE); 
//making Format, which uses font
WritableCellFormat   form   =   new WritableCellFormat( ft);

Number nb = ( Number ) getcl ;          
nb.setCellFormat( form );    


wkr.write();
wkr.close();

Answer 4

我个人使用此代码附加xls文件并创建一个（如果不存在）。
使用jxl 2.6：

    public class Excel {

        private String fileName = "excel_file.xls";
        private String sheetName = "sheet1";
        private WritableWorkbook writableWorkbook;
        private int rowCount;
        private Workbook wb;

// assigns checks if file exists or not, both cases we assign it to a WritableWorkbook // object so that we can write to it.
        private void assignWorkBook() throws IOException, BiffException {
    //        File f = new File(System.getProperty("user.dir") +"\\"+fileName);
            File inp = new File(fileName);
            try{
                wb = Workbook.getWorkbook(inp);
                writableWorkbook = Workbook.createWorkbook(inp, wb);
            } catch (FileNotFoundException e){
                writableWorkbook = Workbook.createWorkbook(inp); //Create a new one
            }
        }

        public int getRowCount() {
            return rowCount;
        }

// this function writes a vector to an excel file, checks if there is already a sheet 
// with that name or not, and uses it. then we have to close the Workbook object before 
// we could write to the file, and then we save the file.
// That is, the file is always saved after writing to it.

        public void writeRow(Vector<String> playerVector) throws WriteException, IOException, BiffException {
            assignWorkBook();
            WritableSheet excelSheet;
            if(writableWorkbook.getNumberOfSheets() == 0) {
                excelSheet = writableWorkbook.createSheet(sheetName, 0);
            }
            else {
                excelSheet = writableWorkbook.getSheet(sheetName);
            }
            rowCount = excelSheet.getRows();
            int colCount = 0;
            for(String playerStat:playerVector) {
                Label label = new Label(colCount++, rowCount, playerStat);
                excelSheet.addCell(label);
            }
            if(wb != null) {
                wb.close();
            }
            writableWorkbook.write();
            writableWorkbook.close(); //everytime save it.
        }
    }

使用jxl修改现有的Excel

4 个答案: