1.文件上传

（1）文件类型

<form id="uploadForm" role="form" action="" method="post" enctype="multipart/form-data"> <div class="form-group"> <input type="file" id="inputFile" name="selectFile" multiple="multiple" class="form-control"/> </div> </form>

注意：enctype="multipart/form-data"  是用来设置表单的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。multiple="multiple" 设置该属性可以一次选择多个文件（批量上传可以使用）。

（2）提交方式

  可以使用ajax提交form表单：$("#uploadForm").submit(); 

  如果需要传递带参数的url可以先给action赋值：$("#uploadForm").attr('action',‘url?id=’+id);   然后再提交表单。 

 （3）上传后台代码

public void uploadFile(HttpServletRequest request, HttpServletResponse response) throws Exception { MultipartHttpServletRequest mulRequest = (MultipartHttpServletRequest) request; MultipartFile mFile = mulRequest.getFile("selectFile"); // 得到上传文件 // 获得项目部署路径（默认在Tomact的webapps目录下） String path = request.getSession().getServletContext().getRealPath(""); String fileName = mFile.getOriginalFilename(); // 得到上传文件的文件名 InputStream inputStream = mFile.getInputStream(); byte[] buff = new byte[1048576]; // 设置文件大小 int length = inputStream.read(buff); //将文件上传到aa文件夹下 //path = path + "aa/" + fileName; // Linux环境 path = path + "aa\\" + fileName; // Windows环境 FileOutputStream outputStream = new FileOutputStream(path); // 文件流写到服务器 outputStream.write(buff, 0, length); inputStream.close(); outputStream.close(); }

2.文件下载

 

public void downloadFile(HttpServletRequest request, HttpServletResponse response) throws Exception { response.setContentType("text/html;charset=UTF-8"); request.setCharacterEncoding("UTF-8"); BufferedInputStream bis = null; BufferedOutputStream bos = null; String fileName = request.getParameter("fileName"); // 下载文件名 String ctxPath = request.getSession().getServletContext().getRealPath("");// 获得项目部署路径 ctxPath = ctxPath + "aa\\" + fileName; // Windows环境 //ctxPath = ctxPath + "aa/" + fileName;// Linux环境 long fileLength = new File(ctxPath).length(); response.setContentType("application/octet-stream"); response.setHeader("Content-disposition", "attachment; filename=" + new String(fileName.getBytes("UTF-8"), "iso-8859-1")); // 解决中文名称乱码问题 response.setHeader("Content-Length", String.valueOf(fileLength)); bis = new BufferedInputStream(new FileInputStream(ctxPath)); bos = new BufferedOutputStream(response.getOutputStream()); byte[] buff = new byte[2048]; int bytesRead; while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) { bos.write(buff, 0, bytesRead); } bis.close(); bos.close(); }