JDBC存儲和讀取二進制數據

以下JSP文件用common-fileupload組件實現文件上傳，并將文件以二進制文件的形式存入數據庫

    <%

    if("POST".equalsIgnoreCase(request.getMethod)){//如果是POST表單

          DiskFileUpload diskFileUpload = newDiskFileUpload();

          diskFileUpload.setHeaderEncoding("UTF-8");//設置編碼

          //解析上傳的數據

          List <FileItem> list =diskFileUpload.parseRequest(request);


      for(FileItem fileItem : list){  
             if(!fileItem.isFormField()){  //如果是文件域  
                    //文件路徑，替換掉特殊字符  
                    String filename =fileItem.getName().replace("\\","/");  
                    //獲取文件名  
                    filename =filename.substring(filename.lastIndexOf("/")+1);  
                    //獲取文件類型  
                    String filetype =fileItem.getContentType();  
                    //獲取文件大小  
                    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();  

      }  

             }  
      }  

}  
%>  </pre><br />

讀取二進制文件 
    <%

    out.clear();  //清空一切輸出

    int id=Integer.parseInt(request.getParameter("id")); //獲取附件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"));//設置輸出的文件類型  
      response.setContentLength(ra.getInt("filesize"));//設置輸出的文件長度  

      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();  
}  

%>  </pre><br />