Spring文件下載方式整理

 

項目中遇到文件下載,所以總結一下遇到的文件下載方式：

 

方法一，返回一個 ResponseEntity，響應實體返回一個字節數組，

 public ResponseEntity<byte[]> exportData() throws IOException {

        HttpHeaders headers=new HttpHeaders();
        headers.setContentDispositionFormData("attachment", new File(filePath).getName());
        headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);

        return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(new File(filePath)),headers, HttpStatus.CREATED);
    }

 ResponseEntity用於構造標識整個http響應：狀態碼、頭部信息以及相應體內容。因此我們可以使用其對http響應實現完整配置。

 

 方法二，通過向響應對象中寫入字符流的方式實現。

 protected void service(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        resp.setCharacterEncoding("utf-8");
        resp.setContentType("application/octet-stream");
       
        resp.setHeader("Content-Disposition", "attachment;filename="+URLEncoder.encode("中國", "utf-8")+".txt");
        PrintWriter os = resp.getWriter();
        String path = this.getServletContext().getRealPath("/download");
        Reader is = new BufferedReader(new FileReader(new File(path,"t.txt")));
        int len=0;
        char[] buffer = new char[200];
        while((len=is.read(buffer))!=-1){
            os.print(new String(buffer,0,len));
        }
        is.close();
        os.close();
    }
}