上传多张图片文件到服务器

　　
    List<File> imageLists = new ArrayList<>(); 

    File photo1file = new File(getContext().getExternalFilesDir("photos").getPath(), photo1.toFileName());

    File photo2file = new File(getContext().getExternalFilesDir("photos").getPath(), photo2.toFileName());

    private static final MediaType MEDIA_TYPE_IAMGE = MediaType.parse("image/*");
    /**
     * okHttp post异步请求表单提交
     *
     * @param actionUrl 接口地址
     * @param paramsMap 请求参数
     * @param fileParamName 图片参数的名字
     * @param imageLists 图片参数的列表
     * @param callBack  请求返回数据回调
     * @param <T>       数据泛型
     * @return
     */
    public <T> Call requestPostByAsynWithImageList(String actionUrl, HashMap<String, String> paramsMap, String fileParamName, List<File> imageLists, final ReqCallBack<T> callBack) {
        try {
            MultipartBody.Builder builder = new MultipartBody.Builder().setType(MultipartBody.FORM);
            for (String key : paramsMap.keySet()) {
//                builder.add(key, paramsMap.get(key));
                builder.addFormDataPart(key,paramsMap.get(key));
            }
            for(File image : imageLists) {
                builder.addFormDataPart(fileParamName, image.getName(), RequestBody.create(MEDIA_TYPE_IAMGE, image));
            }
            RequestBody formBody = builder.build();
            String requestUrl = String.format("%s/%s", WebUrls.baseurl, actionUrl);
            final Request request = addHeaders().url(requestUrl).post(formBody).build();
            final Call call = mOkHttpClient.newCall(request);
            call.enqueue(new Callback() {
                @Override
                public void onFailure(Call call, IOException e) {
                    failedCallBack("访问失败", callBack);
                    Log.e(TAG, e.toString());
                }

                @Override
                public void onResponse(Call call, Response response) throws IOException {
                    if (response.isSuccessful()) {
                        String string = response.body().string();
                        String header=response.header("Content-MD5");
                        Log.e(TAG, "response ----->" + string);
                        successCallBack((T) string,header, callBack);
                    } else {
                        failedCallBack("服务器错误", callBack);
                    }
                }
            });
            return call;
        } catch (Exception e) {
            Log.e(TAG, e.toString());
        }
        return null;
    }