for input String :""怎么解决?

try {
int auctionid = Integer.parseInt(request.getParameter("auctionid").trim()) ;
Double price=Double.parseDouble(request.getParameter("auctionPrice"));
SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
Date date = Calendar.getInstance().getTime();
String time=sdf.format(date);
Integer userId = ((Auctionuser)request.getSession().getAttribute("user")).getUserid();
Auctionrecord auct =new Auctionrecord();
Auction auction =new Auction();
auction.setAuctionid(new Integer(auctionid));
Auctionuser user =new Auctionuser();
user.setUserid(userId);

auct.setAuctionId(auctionid);
auct.setAuctionuser(user);
auct.setAuctiontime(sdf.parse(time));
auct.setAuctionprice(price);

            int num= service.AddAuct(auct);  
                if (num>0){
                    out.print(
                            "<script type=\"text/javascript\">"+
                            "alert(\"竞拍成功!!!\");"+
                            "location.href=\"AuctionrecordServlet?opr=auctor&id=1\";"+
                        "</script>"
                    );
                }else {
                    out.print(
                            "<script type=\"text/javascript\">"+
                            "alert(\"竞拍失败!!!\");"+
                            "location.href=\"AuctionrecordServlet?opr=auctor&id=1\";"+
                        "</script>"
                    );
                }
        } catch (Exception e) {
            e.printStackTrace();
        }

}

http://blog.csdn.net/xzongyuan/article/details/40399047