Jxl对已有的excel追加数据或修改数据

public class ExcelTest {  
	  
	    /** 
	     * @param args 
	     * @throws IOException  
	     * @throws BiffException  
	     * @throws WriteException  
	     */  
	    public static void main(String[] args) throws IOException, BiffException, WriteException {  
	        
	        Workbook wb = null;
	        WritableWorkbook wwb = null;
	        try {


	            wb = Workbook.getWorkbook(new File("src\\jxlrwtest.xls"));            
	            wwb = Workbook.createWorkbook(new File("src\\jxlrwtest.xls"),wb);    // 在原有工作簿jxlrwtest.xls上追加数据
	            if (wb != null && wwb != null) {


	                WritableSheet sheet = wwb.getSheet(0);                                    
	                WritableCell cell = sheet.getWritableCell(0, 0);         // 修改第一页的第一行第一列数据


	                if (cell.getType() == CellType.LABEL) {
	                    Label l = (Label) cell;
	                    l.setString("modified cell2353");             // 设置数据
	                }
	                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();
	        }
	        
	    }  
	  
	}