文件上传与下载

springmvc文件上传

control层

@ResponseBody@RequestMapping(value = "/addKnowledgeFile")public ModelAndView addKnowledgeFile(@RequestParam(value = "file", required = false) MultipartFile file,HttpServletRequest request,HttpServletResponse response,String knowledgeId,  String categoryId, String details) {XSmKnowledge knowledge = new XSmKnowledge();boolean isMulitpart = ServletFileUpload.isMultipartContent(request);if (isMulitpart) {try {String originalFileName = file.getOriginalFilename(); // 原始的文件名//通过ftp上传文件/ 1.img 2.video 3.other分类排放, 保存的绝对路径String filePath = FtpClientUtil.sendFile(MUOContext.getUserId(), originalFileName,file.getInputStream());knowledge.setFilepath(filePath);} catch (IOException e) {e.printStackTrace();} catch (Exception e) {e.printStackTrace();}}knowledge.setKnowledgeId(knowledgeId);xSmKnowledgeService.updateKnowledge(knowledge);ModelAndView view = new ModelAndView("redirect:/{appName}/study/xsmknowledge/updateKnowledge");return view;}

上传的页面

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表单中enctype="multipart/form-data"的意思，是设置表单的MIME编码。默认情况，这个编码格式是application/x-www-form-urlencoded，不能用于文件上传；
只有使用了multipart/form-data，才能完整的传递文件数据，进行下面的操作.enctype="multipart/form-data"是上传二进制数据; form里面的input的值以2进制的方式传过去。
form里面的input的值以2进制的方式传过去，所以request就得不到值了。也就是说加了这段代码,用request就会传递不成功,取表单值加入数据库时，用到下面的：SmartUpload su = new SmartUpload();//新建一个SmartUpload对象su.getRequest().getParameterValues();取数组值su.getRequest().getParameter( );取单个参数单个值

<form  id="kb_upload_http" enctype="multipart/form-data" action="${sys.appPath}/study/xsmknowledge/addKnowledgeFile" method="post" name="kb_upload_http" onsubmit="return check()"><fieldset><div class="control-group"><label class="control-label"> 上传本地文件(允许上传文件类型: doc;docx;ppt;pptx;xls;xlsx;)</label><div class="controls"><input class="inputText" style="width:50%" id="upload_file_local" accept="" name="file" type="file" /></div></div><div class="control-group"><label class="control-label">  </label><div class="controls"><button type="button" class="btn loading" onclick="javascript:window.location.href='${sys.appPath}/study/xsmknowledge/updateKnowledge';" name="cancle" >上一步</button> <button class="btn btn-primary" name="submit" type="submit" >上传</button> <button type="button" class="btn" onclick="javascript:art.dialog.close();" name="cancle" >取消</button></div></div><input name="_qf__kb_upload_http" type="hidden" value="" />      <input name="kb_type" type="hidden" value="file" />       <input name="knowledgeId" type="hidden" value="${list.knowledgeId }" />      <input name="id" type="hidden" value="98" />      <input name="location" type="hidden" value="http" />      <input name="MAX_FILE_SIZE" type="hidden" value="838860800" /></fieldset></form>

/** * 通过ftp上传文件/ 1.img 2.video 3.other分类排放 *  * @param userid * @param file * @return 保存的绝对路径 */public static String sendFile(String userid, String filename, InputStream in)throws Exception {FTPClient ftpclient = new FTPClient();try {if(!ftpclient.isConnected()){ftpclient.connect(FTP_HOST, FTP_PORT);int reply = ftpclient.getReplyCode();if (!FTPReply.isPositiveCompletion(reply)) {// 连接错误的时候报错。throw new Exception("Can't Connect to :" + FTP_HOST);}// 登录if (ftpclient.login(FTP_USER, FTP_PWD) == false) {throw new Exception("Invalid user/password");}// 设置传送文件模式ftpclient.setFileType(FTP.BINARY_FILE_TYPE);ftpclient.setControlEncoding("utf-8");}// 传送文件String suffixname = filename.substring(filename.lastIndexOf(".") + 1).toUpperCase();String basePath = "";switch (suffixname) {case "MP4":basePath = FTP_VIDEO_PATH;break;case "JPG":case "PNG":case "GIF":case "JPGE":case "BMP":basePath = FTP_IMAGE_PATH;break;default:basePath = FTP_OTHER_PATH;}String path="";if(!ftpclient.changeWorkingDirectory(FTP_ROOT_PATH)){//如果没有change成功，表明没成功cwdftpclient.makeDirectory(FTP_ROOT_PATH);ftpclient.changeWorkingDirectory(FTP_ROOT_PATH);}path+=File.separatorChar+FTP_ROOT_PATH;if (!ftpclient.changeWorkingDirectory(basePath)) {// 如果没有change成功，表明没成功cwdftpclient.makeDirectory(basePath);}ftpclient.changeWorkingDirectory(basePath);path+=File.separatorChar+basePath;if (!ftpclient.changeWorkingDirectory(userid)) {// 如果没有change成功，表明没成功cwdftpclient.makeDirectory(userid);ftpclient.changeWorkingDirectory(userid);}path+=File.separatorChar+userid;String webFilePath = UUIDUtil.getUUID() + "."+ suffixname.toLowerCase();boolean success = ftpclient.storeFile(webFilePath, in);if (success) {return path + File.separatorChar+ webFilePath;} else {throw new Exception("保存失败");}} catch (Exception e) {throw e;} finally {if (in != null) {in.close();}}}

文件下载

@RequestMapping(value = "/showKnowledgeDetails")public ModelAndView showKnowledgeDetails(String knowledgeId) {XSmKnowledge xSmKnowledge = xSmKnowledgeService.selectKnowledgeDetailById(knowledgeId);//把\转为/xSmKnowledge.setFilepath(xSmKnowledge.getFilepath().replace("\\", "/"));//拼接路径xSmKnowledge.setFilepath("http://"+nginxHost+":"+nginxPort+xSmKnowledge.getFilepath());ModelAndView view = new ModelAndView("/mgr/showKnowledgeDetail");view.addObject("knowledgeList", xSmKnowledge);view.addObject("filePath", xSmKnowledge.getFilepath());return view;}

<a href="${sys.appPath }/study/xsmknowledge/showKnowledgeDetails?knowledgeId=${list.knowledgeId }"  class="btn btn-primary" style="color:#FFF" target="_blank">查看详细内容</a>