Excel 日期转换

public static void importExcel2(File file) throws Exception, IOException {
        Workbook book  =  Workbook.getWorkbook(file);
        //  获得第一个工作表对象 
        Sheet sheet  =  book.getSheet( 0 );
        //  得到第一列第一行的单元格 
         int  columnum  =  sheet.getColumns(); //  得到列数 
         int  rownum  =  sheet.getRows(); //  得到行数 
        System.out.println(columnum);
       System.out.println(rownum);
        for  ( int  i  =   1 ; i  <  rownum; i ++ ) //  循环进行读写 
         {
//            for  ( int  j  =   0 ; j  <  columnum; j ++ )  {
//           } 
             CaseInfor caseInfor = new CaseInfor();
            System.out.print(sheet.getCell(0, i).getContents());
            caseInfor.title=sheet.getCell(0, i).getContents();
//            if(sheet.getCell(0, i).getContents()==""){
//                 flash.put("error", "标题不能为空");
//                 list(null,null);
//            }
            
            
            Cell cell1  =  sheet.getCell(1, i);
            if(sheet.getCell(1, i).getType() == CellType.DATE){
                DateCell dc = (DateCell)cell1;
                    Date date = dc.getDate();
                        SimpleDateFormat ds = new SimpleDateFormat("yyyy-MM-dd");
                        String    cellcon = ds.format(date);
                            System.out.print(cellcon);
                             System.out.print( " \t " );
                             caseInfor.acceptTime=date;
          }
            Cell cell2  =  sheet.getCell(2, i);
            if(sheet.getCell(1, i).getType() == CellType.DATE){
                DateCell dc = (DateCell)cell2;
                Date date = dc.getDate();
                SimpleDateFormat ds = new SimpleDateFormat("yyyy-MM-dd");
                String    cellcon = ds.format(date);
                System.out.print(cellcon);
                 caseInfor.deadTime=date;
                System.out.print( " \t " );
            }
            caseInfor.department=sheet.getCell(3, i).getContents();
            caseInfor.process=sheet.getCell(4, i).getContents();
            caseInfor.account=sheet.getCell(5, i).getContents();
            caseInfor.information=sheet.getCell(6, i).getContents();
            caseInfor.mandatory=sheet.getCell(7, i).getContents();
            caseInfor.save();
       } 
       book.close();
       flash.put("success", "导入成功");
       list(null,null);
    }