java 后台请求其他接口转发文件

<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.3</version>
</dependency>
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpmime</artifactId>
    <version>4.5.3</version>
</dependency>

/**
     * 使用httpclint 发送文件
     * @param url: 接口全路径
     * @param file: 上传文件
     * @param fileParamName: 接口对应文件的参数名:相当于@RequestParam("fileParamName")
     * @param headerParams: 请求头信息: 可能需要携带token,注意不要设置content-type
     * @param otherParams: 其他参数
     * @return
     */
    public static String uploadApiFile(String url ,MultipartFile file,String fileParamName,Map<String,String>headerParams,Map<String,String>otherParams) {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        String result = "";
        try {
            String fileName = file.getOriginalFilename();
            HttpPost httpPost = new HttpPost(url);
            //添加header
            for (Map.Entry<String, String> e : headerParams.entrySet()) {
                httpPost.addHeader(e.getKey(), e.getValue());
            }
            MultipartEntityBuilder builder = MultipartEntityBuilder.create();
            builder.setCharset(Charset.forName("utf-8"));
            builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);//加上此行代码解决返回中文乱码问题
            builder.addBinaryBody(fileParamName, file.getInputStream(), ContentType.MULTIPART_FORM_DATA, fileName);// 文件流
            for (Map.Entry<String, String> e : otherParams.entrySet()) {
                builder.addTextBody(e.getKey(), e.getValue());// 类似浏览器表单提交，对应input的name和value
            }
            HttpEntity entity = builder.build();
            httpPost.setEntity(entity);
            HttpResponse response = httpClient.execute(httpPost);// 执行提交
            HttpEntity responseEntity = response.getEntity();
            if (responseEntity != null) {
                // 将响应内容转换为字符串
                result = EntityUtils.toString(responseEntity, Charset.forName("UTF-8"));
            }
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                httpClient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return result;
    }