Retrofit 上传文件

文件流的形式：

    @Multipart
    @POST("/upload")
    LiveData<ApiResponse<String>> voucherUpload(@Part MultipartBody.Part part);

public LiveData<ApiResponse<String>> getVoucherUpload(LiveData path) {
        LiveData voucherData = Transformations.switchMap(data, input -> {
            File file = new File(path);
            RequestBody fileRQ = RequestBody.create(MediaType.parse("image/*"), file);
            MultipartBody.Part part = MultipartBody.Part.createFormData("picture", file.getName(), fileRQ);
            return getApiService().voucherUpload(part);
        });
        return voucherData;
    }

方式二：

public static Call<Bean> upload(UploadApi api,byte[] img) {
    Map<String, Object> params = new HashMap<>();
    RequestBody requestBody = RequestBody.create(MediaType.parse("multipart/form-data"), img);
    return api.upload(params,requestBody);
}
 
 
@Multipart
@POST("upload")
Call<Bean> upload(@QueryMap Map<String, Object> maps, @Part("img\"; filename=\"img.jpg\"")RequestBody img);
 
 
MediaType.parse("multipart/form-data")    对应    @Multipart
 
@Part("img\"; filename=\"img.jpg\"")RequestBody img    
  
img是上传的时候，参数名

文件转为二进制：

/***
     * @param spec 图片路径
     * @return url请求结果
     */
    public static byte[] BufferStreamForByte(String spec) {
        byte[] content = null;
        try {
            BufferedInputStream bis = null;
            ByteArrayOutputStream out = null;
            try {
                FileInputStream input = new FileInputStream(spec);
                bis = new BufferedInputStream(input, 1024);
                byte[] bytes = new byte[1024];
                int len;
                out = new ByteArrayOutputStream();
                while ((len = bis.read(bytes)) > 0) {
                    out.write(bytes, 0, len);
                }
                bis.close();
                content = out.toByteArray();
            } finally {
                if (bis != null)
                    bis.close();
                if (out != null)
                    out.close();
            }
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return content;
    }