如何用JSP实现JSP下载文件功能？

[lhua_1225]

如何实现下述功能：
1）点击按钮，并取得服务器上的文件
2）出现保存文件对话框，用户可以保存该文件或者取消，并且对话框能知道文件类型。

[xiyuan1999]

SmartUpLoad就可以了

或者cos

[liu_shui8]

有个第三方Bean让你用：jspsmart;

[kokolodo]

嗯，可以用第三方ｊａｒ包，就是楼上说的SmartUpLoad就可以了！

[For_suzhen]

直接用java的读写流类就可以了，读取文件写到response里面，frush一下就直接弹出文件保存的对话框了，这是浏览器自带的。有一个参数就是设置文件名的，不仅仅是扩展名，全名都有

[伍子V5]

类似这样

public ActionForward download(ActionMapping mapping, ActionForm form,
			HttpServletRequest request, HttpServletResponse response)
			throws Exception {
		if (logger.isDebugEnabled()) {
			logger.debug("entering 'AttachmentAction.download()' method...");
		}
		ActionMessages messages = new ActionMessages();

		String id = request.getParameter("id");
		String attachmentFile=request.getParameter("file");
		String type = request.getParameter("type");
		if (id != null||attachmentFile!=null) {
			Attachment attachment =null;
			if(id!=null) {
				attachment= mgr.view(id);
			} else if(attachmentFile!=null) {
				attachment=mgr.viewByFile(attachmentFile);
			}

			if (attachment == null) {
				messages.add(ActionMessages.GLOBAL_MESSAGE, new ActionMessage(
						"object.miss"));
				saveMessages(request, messages);
				return mapping.findForward("failure");
			}
			//filename=new String(filename.getBytes("iso-8859-1"),"gb2312");
			//String filepath=this.getServletContext().getRealPath("/upload");
			File file = new File(mgr.getRoot()+"/"+attachment.getAttachmentFile());
			String fileName = URLEncoder.encode(attachment.getAttachment(),
					"UTF-8");
			BufferedInputStream br = new BufferedInputStream(
					new FileInputStream(file));
			byte[] buf = new byte[1024 * 1024];
			int len = 0;
			response.reset(); //纯下载方式
			//response.setContentType("application/x-msdownload"); 
			if (type == null) {
				response
						.setContentType("application/octet-stream;charset=utf-8");
				response.setCharacterEncoding("UTF-8");
				response.setHeader("Content-Disposition",
						"attachment; filename=" + fileName);
			} else if (type != null && type.equals("jpg")) {
				response.setHeader("Cache-Control", "no-store");
				response.setDateHeader("Expires", 0);
				response.setContentType("image/jpeg");
			}
			OutputStream out = response.getOutputStream();
			while ((len = br.read(buf)) > 0)
				out.write(buf, 0, len);
			br.close();
			out.close();
		}
		return null;
	}

[daixiaolong_1588466]

正在找呵呵