java代码上传文件，接口consumes = "multipart/*",headers = "content-type=multipart/form-data"

public static String doPost(String url,String fileName, File file) {
    CloseableHttpClient httpClient = null;
    CloseableHttpResponse response = null;
    String result = "";
    try {
        // 通过址默认配置创建一个httpClient实例
        httpClient = HttpClients.createDefault();
        HttpPost httpPost = new HttpPost(url);
        if (file != null) {
            MultipartEntityBuilder builder = MultipartEntityBuilder.create();
            builder.setCharset(java.nio.charset.Charset.forName("UTF-8"));
            builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
            // 文件流
            builder.addBinaryBody(fileName, new FileInputStream(file), ContentType.MULTIPART_FORM_DATA, file.getName());
            HttpEntity entity = builder.build();
            httpPost.setEntity(entity);
        }
        // 设置配置请求参数
        RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(35000)// 连接主机服务超时时间
                .setConnectionRequestTimeout(35000)// 请求超时时间
                .setSocketTimeout(60000)// 数据读取超时时间
                .build();
        // 为httpGet实例设置配置
        httpPost.setConfig(requestConfig);
        // 执行get请求得到返回对象
        response = httpClient.execute(httpPost);
        // 通过返回对象获取返回数据
        HttpEntity entity = response.getEntity();
        // 通过EntityUtils中的toString方法将结果转换为字符串
        result = EntityUtils.toString(entity);
    } catch (ClientProtocolException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } catch (Exception e) {
        e.printStackTrace();
    } finally {
        // 关闭资源
        if (null != response) {
            try {
                response.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        if (null != httpClient) {
            try {
                httpClient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    return result;
}