JDBC儲存和讀取位元據，jdbc儲存二進位

JDBC儲存和讀取位元據，jdbc儲存二進位

以下JSP檔案用common-fileupload組件實現檔案上傳，並將檔案以二進位檔案的形式存入資料庫

<%if("POST".equalsIgnoreCase(request.getMethod)){//如果是POST表單      DiskFileUpload diskFileUpload = newDiskFileUpload();      diskFileUpload.setHeaderEncoding("UTF-8");//設定編碼      //解析上傳的資料      List <FileItem> list =diskFileUpload.parseRequest(request);           for(FileItem fileItem : list){             if(!fileItem.isFormField()){  //如果是檔案域                    //檔案路徑，替換掉特殊字元                    String filename =fileItem.getName().replace("\\","/");                    //擷取檔案名稱                    filename =filename.substring(filename.lastIndexOf("/")+1);                    //擷取檔案類型                    String filetype =fileItem.getContentType();                    //擷取檔案大小                    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();       }              }      } }%>

 

讀取二進位檔案

<%out.clear();  //清空一切輸出int id=Integer.parseInt(request.getParameter("id")); //擷取附件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();  //重設response      response.setContentType(rs.getString("fileType"));//設定輸出的檔案類型      response.setContentLength(ra.getInt("filesize"));//設定輸出的檔案長度       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("沒有找到附件："+id);      } }finally{      if(rs! = null)  rs.close();      if(preStmt != null)  preStmt.close();      if(conn != null)  conn.close();} %>