public void readTO() {         Workbook wb = null;         WritableWorkbook wwb = null;         try {             File is = new File(System.getProperty("user.dir") + "\\in.xls");             File os = new File(System.getProperty("user.dir") + "\\out.xls");             if (!os.isFile())// 如果指定文件不存在，则新建该文件                 os.createNewFile();             wb = Workbook.getWorkbook(is);// 获取数据源in.xls工作簿对象             wwb = Workbook.createWorkbook(os, wb);// 在原有工作簿out.xls上追加数据             // wwb = Workbook.createWorkbook(os);//区别于上一行代码，创建一个新的写入工作簿             if (wb != null && wwb != null) {                 WritableSheet sheet = wwb.getSheet(0);// 获取out.xls第一个sheet                 WritableCell cell = sheet.getWritableCell(2, 4);// 获取out.xls要写入数据的单元格                 Sheet[] sheets = wb.getSheets();// 获取数据源in.xls的sheets                 Cell[] cells = sheets[0].getRow(1);// 获取in.xls第一个sheet的第二行                 if (cell.getType() == CellType.LABEL) {                     Label l = (Label) cell;                     l.setString(cells[1].getContents());// 将第二个单元格写入out.xls的第三列第五行                 }                 wwb.write();                 System.out.println("工作簿写入数据成功！");             }             wwb.close();// 关闭         } catch (Exception e) {             e.printStackTrace();         } finally {             wb.close();         }     }