Retrofit 2.0 上传文件

1.用MultipartBody.Part的方式上传文件（单文件上传）（表单方式）

 @Multipart
  @POST("xxx/xxx")
  Call<ResponseBody> upload(@Part MultipartBody.Part part);

其中的“photos”是与服务器端预定的文件参数名

2.用RequestBody的方式上传文件（表单方式，可多上传）

 /**
     * 多张图片上传
     */
    private void initUpateBitmap2() {

        //获取图片路径,这只是个简单的例子，项目开发中会有很多图片需要上传，一般从相册和相机里获取，并且保存到后台服务器时必须自己定义名字
        // ，这样就不会发生图片替换（原因名字重复）
        File file = new File(Environment.getExternalStorageDirectory() + "/" + "retrofit/" + "ceshi.jpg");
        File file2 = new File(Environment.getExternalStorageDirectory() + "/" + "retrofit/" + "ceshi2.jpg");
        File file3 = new File(Environment.getExternalStorageDirectory() + "/" + "retrofit/" + "ceshi3.jpg");
        File file4 = new File(Environment.getExternalStorageDirectory() + "/" + "retrofit/" + "ceshi4.jpg");

        RequestBody requestBody = RequestBody.create(MediaType.parse("multipart/form-data"), file);
        RequestBody requestBody2 = RequestBody.create(MediaType.parse("multipart/form-data"), file2);
        RequestBody requestBody3 = RequestBody.create(MediaType.parse("multipart/form-data"), file3);
        RequestBody requestBody4 = RequestBody.create(MediaType.parse("multipart/form-data"), file4);
        RequestBody body = RequestBody.create(MediaType.parse("multipart/form-data"), file);
        //传一张图片就要增加一个参数
        String name = "photo"; filename="ceshi.jpg"";
        String name2 = "photo"; filename="ceshi2.jpg"";
        String name3 = "photo"; filename="ceshi3.jpg"";
        String name4 = "photo"; filename="ceshi4.jpg"";
        HashMap<String, RequestBody> map = new HashMap<>();
        map.put(name, requestBody);
        map.put(name2, requestBody2);
        map.put(name3, requestBody3);
        map.put(name4, requestBody4);

        RetrofitHelper.getInstance().uploadFile2(map, new RetrofitHelper.OnSuccessListener() {
            @Override
            public void onSuccess(Object o) {
                Log.e("", "成功");
            }

            @Override
            public void onFaile() {
                Log.e("", "失败");

            }
        });
    }

通用的带参数和文件上传

接口定义，注意这个时候没有@Multipart

 @POST("upload")
 Call<ResponseBody> uploadFile(@Body RequestBody body);

 RequestBody body=new MultipartBody.Builder().setType(MultipartBody.FORM)
                .addFormDataPart("userName","lange")
                .addFormDataPart("token","dxjdkdjkj9203kdckje0")
                .addFormDataPart("header",file.getName(),fileRQ)
                .build();
        Call<ResponseBody> uploadCall = downloadService.uploadFile(body);

或者 

 @Multipart
  @POST("postFied")
  Call<Void> postFied(@PartMap Map<String,String> map, @Part MultipartBody.Part file);



File file=new File("/sdcard/shumei.txt");
        RequestBody  body=RequestBody.create(MediaType.parse("application/octet-stream"),file);
//        RequestBody  body=RequestBody.create(MediaType.parse("multipart/form-data"),file);
        MultipartBody.Part part =MultipartBody.Part.createFormData("file",file.getName(),body);
        Map<String, String> map = new HashMap<>();
        map.put("name","123456");
        Call<Void> liing = api.postFied(map,part);