0

Jsf：如何在没有上传按钮的情况下将文件上传到服务器.??

我有一个生成 Excel 文件按钮。如何通过单击 Excel 文件按钮将其上传到服务器并返回从服务器下载文件的链接？

  public void contextInitialized(ServletContextEvent servletContextEvent) {
        String rootPath = System.getProperty("catalina.home");
        ServletContext ctx = servletContextEvent.getServletContext();
        String relativePath = ctx.getInitParameter("tempfile.dir");
        File file = new File(rootPath + File.separator + relativePath);
        if(!file.exists()) file.mkdirs();
        System.out.println("File Directory created to be used for storing files");
        ctx.setAttribute("FILES_DIR_FILE", file);
        ctx.setAttribute("FILES_DIR", rootPath + File.separator + relativePath);
    }

    public void contextDestroyed(ServletContextEvent servletContextEvent) {
        //do cleanup if needed
    }

    @Override
    public void init() throws ServletException{
        DiskFileItemFactory fileFactory = new DiskFileItemFactory();
        File filesDir = (File) getServletContext().getAttribute("FILES_DIR_FILE");
        fileFactory.setRepository(filesDir);
        this.uploader = new ServletFileUpload(fileFactory);
    }
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        if(!ServletFileUpload.isMultipartContent(request)){
            throw new ServletException("Content type is not multipart/form-data");
        }

        response.setContentType("text/html");
        PrintWriter out = response.getWriter();
        out.write("<html><head></head><body>");
        try {
            List<FileItem> fileItemsList = uploader.parseRequest(request);
            Iterator<FileItem> fileItemsIterator = fileItemsList.iterator();
            while(fileItemsIterator.hasNext()){
                FileItem fileItem = fileItemsIterator.next();
                System.out.println("FieldName="+fileItem.getFieldName());
                System.out.println("FileName="+fileItem.getName());
                System.out.println("ContentType="+fileItem.getContentType());
                System.out.println("Size in bytes="+fileItem.getSize());

                File file = new File(request.getServletContext().getAttribute("FILES_DIR")+File.separator+fileItem.getName());
                System.out.println("Absolute Path at server="+file.getAbsolutePath());
                fileItem.write(file);
                out.write("File "+fileItem.getName()+ " uploaded successfully.");
                out.write("<br>");
                out.write("<a href=\"UploadDownloadFileServlet?fileName="+fileItem.getName()+"\">Download "+fileItem.getName()+"</a>");
            }
        } catch (FileUploadException e) {
            out.write("Exception in uploading file.");
        } catch (Exception e) {
            out.write("Exception in uploading file.");
        }
        out.write("</body></html>");
    }  enter code here
4

0 回答 0