retrofit post请求上传表单和文件最重要的就是就是去构建RequestBody，今天为大家带来一种超级简单的上传方式

Body方式：

1、Retrofit接口RetrofitInterface

 @POST(URLConstant.URL_PATH)
    Flowable<UploadImgBean> upload(@Body RequestBody Body);

2、Retrofit的配置

private static RetrofitInterface getRetrofitInterface(String baseUrl) {
        if (retrofitInterface == null) {
            Retrofit retrofit = new Retrofit.Builder()
                    .baseUrl(baseUrl)
                    .addConverterFactory(GsonConverterFactory.create())
//                .addConverterFactory(ScalarsConverterFactory.create()) //string
                    .addCallAdapterFactory(RxJava2CallAdapterFactory.create())
                    .build();
            retrofitInterface = retrofit.create(RetrofitInterface.class);
        }
        return retrofitInterface;
    }

3、构建body

 public static Flowable<UploadImgBean> upload(List<File> fileList) {
        //构建body
//addFormDataPart()第一个参数为表单名字，这是和后台约定好的
        MultipartBody.Builder builder = new MultipartBody.Builder()
                .setType(MultipartBody.FORM)
                .addFormDataPart("username", "name") 
                .addFormDataPart("phone", "phone")
      //注意，file是后台约定的参数，如果是多图，file[]，如果是单张图片，file就行
        for (File file : fileList) {
            //这里上传的是多图
            builder.addFormDataPart("file[]", file.getName(), RequestBody.create(MediaType.parse("image/*"), file));
        }
        RequestBody requestBody = builder.build();
        return getRetrofitInterface(URLConstant.URL_BASE).upload(requestBody);
    }

4、开始执行上传

HttpUtils.upload(mUploadFileList)
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(new DisposableSubscriber<UploadImgBean>() {
                    @Override
                    public void onNext(UploadImgBean uploadImgBean) {
                        Log.i(TAG, "onNext: " ); 
                        }
                    }

                    @Override
                    public void onError(Throwable throwable) {
                        Log.i(TAG, "onError: --->" + throwable.getMessage());
                    }

                    @Override
                    public void onComplete() {
                        Log.i(TAG, "onComplete: ");
                    }
                });