jsf框架下渲染解析生成xhtml标签时，自己写的AJAX ，返回不了文件上传的进度条？

[CAD GIS开发]

        private void responseFileUploadStatusPoll(HttpServletRequest request,HttpServletResponse response) throws IOException{    
            FileUploadStatus fUploadStatus=(FileUploadStatus)request.getSession().getAttribute(UPLOAD_STATUS);    
            //计算上传完成的百分比    
            System.out.println(fUploadStatus+"-------------fUploadStatus");
            long percentComplete = (long)Math.floor(((double) fUploadStatus.getReadTotalSize()/(double) fUploadStatus.getUploadTotalSize())*100.0);    
            System.out.println("com:"+percentComplete);    
            response.setContentType("text/xml");    
            response.setCharacterEncoding("UTF-8");    
            response.setHeader("Cache-Control", "no-cache");   
            System.out.println(response.getContentType()+"-------------fUploadStatus");
            if ( ((long)fUploadStatus.getReadTotalSize() == (long)fUploadStatus.getUploadTotalSize()) || (fUploadStatus.getCancel() == true)){    
            response.getWriter().write(fUploadStatus.getStatus().toString()+"success");    
            }else{    
                response.getWriter().write(fUploadStatus.getStatus().toString()+"<div class=\"prog-border\"><div class=\"prog-bar\" style=\"width: "    
                                    + percentComplete + "%;\"></div></div>");    
            }    
        }    

[CAD GIS开发]

processFileUpload(request,response); 这个方法里面可以获得 AJAX 每次请求的文件信息，而调用responseFileUploadStatusPoll(）向前台写入进度条信息时，sessionid变化了，不是同一个session，session保存的 对象 文件上传状态对象。

[CAD GIS开发]

        
        protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {    
            boolean isMultipart = ServletFileUpload.isMultipartContent(request);    
                
            if (isMultipart) {    
                processFileUpload(request,response);  
        System.out.println("1111111111111");
            }else{    
                request.setCharacterEncoding("UTF-8");    
                System.out.println("222222222222222"); 
                if (request.getParameter("uploadStatus")!=null){    
                    responseFileUploadStatusPoll(request,response);  
                    System.out.println("3333333333333"); 
                }    
                if (request.getParameter("cancelUpload")!=null){    
                    processCancelFileUpload(request,response);  
                    System.out.println("44444444444444"); 
                }    
            }    
                
        }