服务之间通过接口传输文件（带参数）以及微信上传临时素材（/cgi-bin/media/upload）接口

 public String formDataPost(String url, MultipartFile file) {
        BufferedReader reader = null;
        try {
            URL urlObj = new URL(url);
            HttpURLConnection con = (HttpURLConnection) urlObj.openConnection();
            con.setRequestMethod("POST");
            con.setDoInput(true);
            con.setDoOutput(true);
            // post方式不能使用缓存
            con.setUseCaches(false);
            // 设置请求头信息
            con.setRequestProperty("Connection", "Keep-Alive");
            con.setRequestProperty("Charset", "UTF-8");
            // 设置边界
            String BOUNDARY = "----------" + System.currentTimeMillis();
            con.setRequestProperty("Content-Type", "multipart/form-data; boundary=" + BOUNDARY);
            // 请求正文信息
            // 第一部分：
            StringBuilder sb = new StringBuilder();
            // 必须多两道线
            sb.append("--");
            sb.append(BOUNDARY);
            sb.append("\r\n");
            sb.append("Content-Disposition: form-data;name=\"file\";filename=\"" + file.getOriginalFilename() + "\"\r\n");
            sb.append("Content-Type:application/octet-stream\r\n\r\n");
            byte[] head = sb.toString().getBytes("utf-8");
            // 获得输出流
            OutputStream out = new DataOutputStream(con.getOutputStream());
            // 输出表头
            out.write(head);
            // 文件正文部分
            // 把文件已流文件的方式 推入到url中
            DataInputStream in = new DataInputStream(file.getInputStream());
            int bytes = 0;
            byte[] bufferOut = new byte[1024];
            while ((bytes = in.read(bufferOut)) != -1) {
                out.write(bufferOut, 0, bytes);
            }
            in.close();
            // 结尾部分
            byte[] foot = ("\r\n--" + BOUNDARY + "--\r\n").getBytes("utf-8");// 定义最后数据分隔线
            out.write(foot);
            out.flush();
            out.close();
            StringBuffer buffer = new StringBuffer();
            // 定义BufferedReader输入流来读取URL的响应
            reader = new BufferedReader(new InputStreamReader(con.getInputStream()));
            String line = null;
            while ((line = reader.readLine()) != null) {
                buffer.append(line);
            }
            return buffer.toString();
        } catch (Exception e) {
            log.error("发送POST请求出现异常:{}", e);
        } finally {
            if (reader != null) {
                try {
                    reader.close();
                } catch (IOException e) {
                    log.error("关闭流异常：{}", e);
                }
            }
        }
        throw new BusinessException(ResultCode.ERROR, new Object[]{"请求微信上传媒体文件"});
    }

    /**
     * 上传媒体素材
     * <p>
     *
     * @return
     * @throws
     * @version 1.0.0
     * @date 2020/6/4
     */
    @ApiOperation(value = "上传媒体素材", httpMethod = "POST")
    @PostMapping("/upload")
    public RestResult<UploadMediaResponse> upload(@RequestParam("file") MultipartFile file, @ModelAttribute @Valid @ApiParam(name = "上传媒体素材请求参数") UploadMediaRequest request) {
        return success(uploadMediaService.upload(file, request));
    }

/**
    * 页面上传文件接口
    * <p>
    * @return
    * @throws
    * @version 1.0.0
    * @date  2020/6/6
    */
    @PostMapping("/upload1")
    public RestResult upload1(@RequestParam("file") MultipartFile file, @ModelAttribute @Valid @ApiParam(name = "上传媒体素材请求参数") UploadMediaRequest request) {
        String url = "http://localhost:8359/xxxx/upload";
        HttpHeaders headers = new HttpHeaders();
        headers.add("Accept", MediaType.APPLICATION_JSON.toString());
        headers.setContentType(MediaType.parseMediaType("multipart/form-data; charset=UTF-8"));
        MultiValueMap<String, Object> form = new LinkedMultiValueMap();
        form.add("fileType", request.getFileType());
        form.add("appId", request.getAppId());
        try {
            ByteArrayResource byteArrayResource = this.getByteArrayResource(file.getBytes(), file.getOriginalFilename());
            form.add("file", byteArrayResource);
            HttpEntity<MultiValueMap<String, Object>> requestEntity = new HttpEntity(form, headers);
            ResponseEntity<RestResult> response = restTemplate.exchange(url, HttpMethod.POST, requestEntity, RestResult.class, new Object[0]);
            RestResult body = response.getBody();
            return success(body.getData());
        } catch (Exception e) {
            System.out.println(e);
        }
        return success();
    }

    private ByteArrayResource getByteArrayResource(byte[] fileBytes, final String originalFilename) throws Exception {
        ByteArrayResource byteArrayResource = new ByteArrayResource(fileBytes) {
            public String getFilename() {
                try {
                    return URLEncoder.encode(originalFilename, "UTF-8");
                } catch (Exception e) {
                    return originalFilename;
                }
            }
        };
        return byteArrayResource;
    }