IE瀏覽器在IE11,更改了User-Agent字串格式內容，所以針對IE11,做一下判斷即可：

//下載檔案，並處理檔名亂碼
		public void downloadFile(HttpServletRequest request,HttpServletResponse response){
		   String path = request.getSession().getServletContext().getRealPath("/upload/文件1.doc");
		    // path是根據日誌路徑和檔名拼接出來的
		     File file = new File(path);
		    //獲取日誌檔名稱
		      String filename = file.getName();
		   try {
		      //判斷是否是IE11
		      Boolean flag= request.getHeader("User-Agent").indexOf("like Gecko")>0;
		     
		       if (request.getHeader("User-Agent").toLowerCase().indexOf("msie") >0||flag){
		           filename = URLEncoder.encode(filename, "UTF-8");//IE瀏覽器
		       }else {
		        //先去掉檔名稱中的空格,然後轉換編碼格式為utf-8,保證不出現亂碼,
		        //這個檔名稱用於瀏覽器的下載框中自動顯示的檔名
		        filename = new String(filename.replaceAll(" ", "").getBytes("UTF-8"), "ISO8859-1");
		        //firefox瀏覽器
		        //firefox瀏覽器User-Agent字串: 
		        //Mozilla/5.0 (Windows NT 6.1; WOW64; rv:36.0) Gecko/20100101 Firefox/36.0
		       }
		    InputStream fis = new BufferedInputStream(new FileInputStream(path));
		       byte[] buffer;
		    buffer = new byte[fis.available()];
		       fis.read(buffer);
		       fis.close();
		       response.reset();
		       response.addHeader("Content-Disposition", "attachment;filename=" +filename);
		       response.addHeader("Content-Length", "" + file.length());
		       OutputStream os = response.getOutputStream();
		       response.setContentType("application/octet-stream");
		       os.write(buffer);// 輸出檔案
		       os.flush();
		       os.close();
		   } catch (IOException e) {
		    // TODO Auto-generated catch block
		    e.printStackTrace();
		   }
		  }