/**
 * Rest模板物件，用於http訪問
 * 當前物件已經使用@LoadBanlnced 實現的負載均衡
 */
@Autowired
@Qualifier("siteRestTemplate")
RestTemplate restTemplate;

//閘道器介面

@RequestMapping("/transferRequest/download")
public void transferRequest(String action, String site, String params, String method, Integer timeout, HttpServletResponse httpServletResponse) {
 
    //這裡只需要把服務提供者的applicaitonName和介面名稱寫上即可
    String url = "http://" + site + action;
    HttpHeaders headers = getHttpHeadersByRequest(request);
    headers.setContentType(MediaType.MULTIPART_FORM_DATA);
    MultiValueMap postParams = getPostParams(params);
    HttpEntity<MultiValueMap<String, String>> httpEntity = new HttpEntity(postParams, headers);
 
    HttpMethod requestMethod = "GET".equals(method) ? HttpMethod.GET : HttpMethod.POST;
　　//如果改用實體類接收，檔案的二進位制陣列會自動轉換為字串，需要重新轉換為檔案二進位制陣列，暫時沒找到辦法轉換
    ResponseEntity<byte[]> response = restTemplate.exchange(url, requestMethod, httpEntity, byte[].class);
    LOGGER.info("中轉請求返回：" + response.getStatusCode() + " | " + response.getBody());
 
    try {
        HttpHeaders obj = response.getHeaders();
        String filename = String.valueOf(obj.get("filename"));
        if(filename != null && filename.length()>0){
            filename = filename.replace("[","").replace("]","");
        }
        httpServletResponse.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(filename, "UTF-8"));

        OutputStream outputStream = httpServletResponse.getOutputStream();
        outputStream.write(response.getBody());
        outputStream.flush();
        outputStream.close();
    } catch (IOException e) {
        e.printStackTrace();
    }

}

　　//下載介面

　　@RequestMapping("/liu")
    @ResponseBody
    public void liu(HttpServletResponse response, HttpServletRequest request){
        try {
            File file = new File("D:\\ytzz\\yulin\\excleFilePath\\登記臺賬2020-05-21-18-06-53.xls");
            byte[] bytes = FileUtils.readFileToByteArray(file);
            response.setHeader("filename", URLEncoder.encode(file.getName(), "UTF-8"));
            response.getOutputStream().write(bytes);
            response.getOutputStream().close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }