java  的在线下载文件  .pdf

1.下载资源的本地位置

2.设置响应头

3.下载代码

 1 PeriodicalResource periodicalResource = periodicalResourceService.get(id);

         String filePath = periodicalResource.getAttachment();//获取资源位置

         File file = new File(periodicalBaseDir + filePath);//本地资源位置

         if (file.exists()) {

             response.setContentType("application/force-download");// 设置强制下载不打开

             response.addHeader("Content-Disposition",

                     "attachment;fileName=" + filePath.split("/")[filePath.split("/").length-1]);// 设置文件名

             byte[] buffer = new byte[1024];

             FileInputStream fis = null;

             BufferedInputStream bis = null;

             try {

                 fis = new FileInputStream(file);

                 bis = new BufferedInputStream(fis);

                 OutputStream os = response.getOutputStream();

                 int i = bis.read(buffer);

                 while (i != -1) {

                     os.write(buffer, 0, i);

                     i = bis.read(buffer);

                 }

             } catch (Exception e) {

                 e.printStackTrace();

             } finally {

                 if (bis != null) {

                     try {

                         bis.close();

                     } catch (IOException e) {

                         e.printStackTrace();

                     }

                 }

                 if (fis != null) {

                     try {

                         fis.close();

                     } catch (IOException e) {

                         e.printStackTrace();

                     }

                 }

             }

         }