编译无法运行

package myservlet.control;
import mybean.data.*;
import java.sql.*;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class HandleUpload extends HttpServlet
{   public void init(ServletConfig config) throws ServletException
    { super.init(config);
      try {  Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
          }
       catch(Exception e){}
    }
   public  void  doPost(HttpServletRequest request,HttpServletResponse response)
                        throws ServletException,IOException
   {  HttpSession session=request.getSession(true);
      Login login=(Login)session.getAttribute("login"); //获取用户登录时的Javabean
       boolean ok=true;
       if(login==null)
       { ok=false;
         response.sendRedirect("login.jsp");             //重定向到登录页面
       }
       if(ok==true)
       {  String logname=login.getLogname();
          uploadFileMethod(request,response,logname);    //接受上传文件
       }
   }
   public void uploadFileMethod(HttpServletRequest request,HttpServletResponse response,
String logname) throws ServletException,IOException
   {  UploadFile upFile=new UploadFile();
      String backNews="";
      try{  HttpSession session=request.getSession(true);
            request.setAttribute("upFile",upFile);
            String tempFileName=(String)session.getId();
            File f1=new File(tempFileName);
            FileOutputStream o=new FileOutputStream(f1);
            InputStream in=request.getInputStream();
            byte b[]=new byte[10000];
            int n;
            while( (n=in.read(b))!=-1)
              {   o.write(b,0,n);
              }
            o.close();
            in.close();
            RandomAccessFile random=new RandomAccessFile(f1,"r");
            int second=1;   //读出f1的第2行，析取出上传文件的名字：
            String secondLine=null;
            while(second<=2)
               { secondLine=random.readLine();
                 second++;
               }
//获取第2行中目录符号'\'最后出现的位置：
            int position=secondLine.lastIndexOf('\\');
//截取文件名：
            String fileName=secondLine.substring(position+1,secondLine.length()-1);
            byte  cc[]=fileName.getBytes("ISO-8859-1");
            fileName=new String(cc);
            fileName=fileName.replaceAll(" ","");
            //文件是否由字母或数字组成判断名字
            String checkedStr=fileName.substring(0,fileName.indexOf("."));
            boolean isLetterOrDigit=true;
            for(int i=0;i<checkedStr.length();i++)
            {  char c=checkedStr.charAt(i);
               if(!((c<='z'&&c>='a')||(c<='Z'&&c>='A')||(c<='9'&&c>='0')))
                 {  isLetterOrDigit=false;
                    break;
                 }
            }
            if(isLetterOrDigit==false)
            {  response.sendRedirect("upload.jsp");  //重定向到upload.jsp页面
            }
//保存文件名是上传文件名加会员名为前缀：
            String savedFileName=logname.concat(fileName);
            random.seek(0);
            long  forthEndPosition=0;  //获取第4行回车符号的位置
            int forth=1;
            while((n=random.readByte())!=-1&&(forth<=4))
               {  if(n=='\n')
                    {  forthEndPosition=random.getFilePointer();
                      forth++;
                    }
               }
            //根据客户上传文件的名字，将该文件存入磁盘：
            File dir=new File("D:/java");
            dir.mkdir();
            //首先删除用户曾上传过的图像文件：
            File file[]=dir.listFiles();
            for(int k=0;k<file.length;k++)
            {  if(file[k].getName().startsWith(logname))
                 file[k].delete();
            }
            File savingFile= new File(dir,savedFileName);  //需要新保存的上传文件
            RandomAccessFile random2=new RandomAccessFile(savingFile,"rw");
            random.seek(random.length());
            long endPosition=random.getFilePointer();
            long mark=endPosition;
            int j=1;
           //确定出文件f1中包含客户上传的文件的内容的最后位置，即倒数第6行:
            while((mark>=0)&&(j<=6))
             {   mark--;
                 random.seek(mark);
                 n=random.readByte();
                 if(n=='\n')
                 {    endPosition=random.getFilePointer();
                      j++;
                }
             }
          random.seek(forthEndPosition);
          long startPoint=random.getFilePointer();
          while(startPoint<endPosition-1)
            { n=random.readByte();
              random2.write(n);
              startPoint=random.getFilePointer();
            }
          random2.close();
          random.close();
          String uri="jdbc:sqlserver://127.0.0.1:1433;DatabaseName=Friend";
          Connection con=DriverManager.getConnection(uri," "," ");
          Statement sql=con.createStatement();
          ResultSet rs=sql.executeQuery("SELECT * FROM member where logname =
'"+logname+"'");
          if(rs.next())
          {  if(isLetterOrDigit)
             { int mm=sql.executeUpdate("UPDATE member SET pic= '"+savedFileName+
"' where logname = '"+logname+"'");
               if(mm!=0)
               { backNews=fileName+"成功上传";
                 upFile.setFileName(fileName);
                 upFile.setSavedFileName(savedFileName);
                 upFile.setBackNews(backNews);
               }
             }
           }
          con.close();
          f1.delete();
        }
     catch(Exception exp)
        {  backNews=""+exp;
           upFile.setBackNews(backNews);
        }
     try{  RequestDispatcher dispatcher=
request.getRequestDispatcher("showUploadMess.jsp");//转发
           dispatcher.forward(request, response);
        }
     catch(Exception ee){}
    }
   public  void  doGet(HttpServletRequest request,HttpServletResponse response)
                        throws ServletException,IOException
    {   doPost(request,response);
    }
}
编译无法运行，是哪里错了呢？？？？
--------------------编程问答-------------------- 没有加亮，这代码真难看啊。 --------------------编程问答-------------------- 至少把异常贴出来吧

补充：Java ,  Java EE