JAVA文件下载，pdf预览。

JAVA文件下载
工具类，简单粗暴实用，自己稍作修改即可。

    public ResponseEntity download(String fileName) throws IOException {
       //获取项目路径 你可能需要代码给你贴上了
       // String property = System.getProperty("user.dir");
       //文件路径
        File file = new File(fileName);
        InputStream in = new FileInputStream(file);
        final HttpHeaders headers = new HttpHeaders();
        headers.add("Content-Type", "application/pdf");
        headers.add("Content-Disposition", "attachment; filename=" +java.net.URLEncoder.encode(file.getName(), "UTF-8") );
        return new ResponseEntity<>(IOUtils.toByteArray(in), headers, HttpStatus.OK);
    }

PDF预览

    public  void showPdf(HttpServletResponse response,@RequestParam String paths) throws IOException {
        response.setContentType("application/pdf");
        //paths是文件路径
        FileInputStream in = new FileInputStream(new File(paths));
        OutputStream out = response.getOutputStream();
        byte[] b = new byte[1024];
        while ((in.read(b))!=-1) {
            out.write(b);
        }
        out.flush();
        in.close();
        out.close();
    }