以下JSP文件用common-fileupload组件实现文件上传，并将文件以二进制文件的形式存入数据库

    <%        if("POST".equalsIgnoreCase(request.getMethod)){//如果是POST表单              DiskFileUpload diskFileUpload = newDiskFileUpload();              diskFileUpload.setHeaderEncoding("UTF-8");//设置编码              //解析上传的数据              List <FileItem> list =diskFileUpload.parseRequest(request);                           for(FileItem fileItem : list){                     if(!fileItem.isFormField()){  //如果是文件域                            //文件路径，替换掉特殊字符                            String filename =fileItem.getName().replace("\\","/");                            //获取文件名                            filename =filename.substring(filename.lastIndexOf("/")+1);                            //获取文件类型                            String filetype =fileItem.getContentType();                            //获取文件大小                            Int filesize =fileItem.getSize();                                                              Connection conn = null;              PrepareStatement preStmt = null;                       try{                     conn = DbManager.getConnection();                     preStmt = conn.prepareStatement(        "insert into table_name (filename,filetype,size,content,date) values(?,?,?,?,?)");                              preStmt.setString(1,filename);                     preStmt.setString(2,filetype);                     preStmt.setInt(3,filesize);                     preStmt.setBinaryStream(4,fileItem.getInputStream(),filesize);                     preStmt.setTimestamp(5,newTimestamp(System.currentTimeMills()));                     preStmt.executeUpdate();                       }finally{                     if(preStmt != null)  preStmt.close();                     if(conn != null)  conn.close();                       }                              }              }                 }        %>  

    <%        out.clear();  //清空一切输出        int id=Integer.parseInt(request.getParameter("id")); //获取附件ID                 Connection conn= null;        PrepareStatementpreStmt = null;        ResultSet rs =null;                 try{        conn =DbManager.getConnection();        preStmt =conn.prepareStatement("select from table_name where id = ?");        preStmt.setInt(1,id);        rs =preStmt.executeQuery();                       if(rs.next()){              response.reset();  //重置response              response.setContentType(rs.getString("fileType"));//设置输出的文件类型              response.setContentLength(ra.getInt("filesize"));//设置输出的文件长度                       InputStream ins = null;              OutputStream ous = null;                     try{                     ins = rs.getBinaryStream("content");                     ous = response.getOutputStream();                     byte [] b = new byte[1024];                     int len = 0;                            while((len = ins.read(b)) !=-1){                                   ous.write(b,0,len);                            }                     }finally{                            if(ous != null) ous.close();                            if(ins != null) ins.close();                     }              }else{                     out.println("没有找到附件："+id);              }                 }finally{              if(rs! = null)  rs.close();              if(preStmt != null)  preStmt.close();              if(conn != null)  conn.close();        }                 %>