//打开要修改的xls文件 //文件地址
jxl.Workbook rw = jxl.Workbook.getWorkbook(new File("D:\testwc.xls"));
Sheet rs = rw.getSheet(0);
//创建可写入的Excel工作薄对象(生成新文件) //文件地址
jxl.write.WritableWorkbook wwb = Workbook.createWorkbook(new File("D:\testwc.xls"), rw);
//读取第一张工作表
jxl.write.WritableSheet ws = wwb.getSheet(0);
jxl.write.WritableCell wc = ws.getWritableCell(0, 2);
// 修改第b行a列的数据
Label label=new Label(a,b,值);
ws.addCell(label);
//写入Excel对象
wwb.write();
//关闭可写入的Excel对象
wwb.close();
//关闭只读的Excel对象
rw.close();