Rretrofit文件上传

一、 说明

1.文件上传一般用post请求

2.文件上传的API接口中不能带@FormUrlEncoded参数

3.一般要携带@Multipart(上传文件的标志)

4.接口范例：

@Multipart

@POST("UploadServlet")

Call uploadFile(@PartMap Map params);

或

@Multipart

@POST("UploadServlet")

Call upload(@Part("description") RequestBody description, @Part MultipartBody.Part file);

二、实现单文件上传

1.AP接口

@Multipart
@POST("UploadServlet")
Call upload(@Part("description") RequestBody description,
                          @Part MultipartBody.Part file);

2.具体实现请求代码：

Retrofit retrofit = new Retrofit.Builder()
        .addConverterFactory(GsonConverterFactory.create())
        .baseUrl("http://192.168.12.101:8080/happy/")
        .build();
UploadFileService service = retrofit.create(UploadFileService.class);
File file = new File("/sdcard/Pictures/myPicture/index.jpg");//访问手机端的文件资源，保证手机端sdcdrd中必须有这个文件
RequestBody requestFile =
        RequestBody.create(MediaType.parse("multipart/form-data"), file);

MultipartBody.Part body = MultipartBody.Part.createFormData("aFile", file.getName(), requestFile);

String descriptionString = "This is a description";
RequestBody description =
        RequestBody.create(MediaType.parse("multipart/form-data"), descriptionString);

Call call = service.upload(description, body);
call.enqueue(new Callback() {
    @Override
    public void onResponse(Call call,
                           Response response) {
        System.out.println("success");
    }

    @Override
    public void onFailure(Call call, Throwable t) {
        t.printStackTrace();
    }
});

multipart/form-data表示将数据以二进制的形式传入服务端中的request中，

MultipartBody.Part.createFormData("aFile", file.getName(), requestFile);

中第一个参数是数组名，第二个参数是文件名；将每条数据都必须封住到RequestBody中。如果你以一下方式创建上传文件：

 

 

String filePath = Environment.getExternalStorageDirectory()+File.separator+"love.txt";
File file = new File(filePath);

记得一定得配置用户权限，低级错误，咋就少犯点：

三、实现多文件上传

1接口

@Multipart
@POST("UploadServlet")
Call upload(@Part("description") RequestBody description,
                          @Part MultipartBody.Part file,
                          @Part MultipartBody.Part file2);

2.然后请求代码中也多了一行

File file = new File("/sdcard/Pictures/myPicture/index.jpg");
File file1 = new File("/sdcard/Picuures/myPicture/me.txt");
RequestBody requestFile =
        RequestBody.create(MediaType.parse("applicaiton/otcet-stream"), file);

RequestBody requestFile1 =
        RequestBody.create(MediaType.parse("applicaiton/otcet-stream"), file1);

MultipartBody.Part body1 =
        MultipartBody.Part.createFormData("aFile", file.getName(), requestFile);

MultipartBody.Part body2 =
        MultipartBody.Part.createFormData("aFile", file.getName(), requestFile1);

String descriptionString = "This is a description";
RequestBody description =
        RequestBody.create(MediaType.parse("multipart/form-data"), descriptionString);

Call call = service.upload(description, body1,body2);

3.或者以@PartMap的形式实现多文件上传

①API

@Multipart
@POST("UploadServlet")
Call uploadFile(@PartMap Map params);

②请求代码：

Retrofit retrofit = new Retrofit.Builder()
         .addConverterFactory(GsonConverterFactory.create())
         .baseUrl("http://192.168.12.101:8080/happy/")
         .build();
 UploadFileService service = retrofit.create(UploadFileService.class);
 File file = new File("/sdcard/Pictures/myPicture/index.jpg");
 File file1 = new File("/sdcard/Picuures/myPicture/me.txt");

 RequestBody requestBody = RequestBody.create(MediaType.parse("multipart/form-data"), file);
 RequestBody requestBody1 = RequestBody.create(MediaType.parse("multipart/form-data"), file1);
 Map params = new HashMap<>();

 params.put("file\"; filename=\""+ file.getName(), requestBody);
 params.put("file\"; filename=\""+ file1.getName(), requestBody1);

 Call model = service.uploadFile(params);
 model.enqueue(new Callback() {
     @Override
     public void onResponse(Call call, Response response) {
        Log.i("MainActivity",response.body().toString());
     }

     @Override
     public void onFailure(Call call, Throwable t) {
      Log.i("错误信息：",t.getMessage());
     }
 });

四、图片文件混合上传

@Multipart
@POST(NRConfig.UPDATE_FILES)
Call> updateOneFile(@PartMap Map data,@Part("pic") RequestBody description,@Part MultipartBody.Part file);

使用@Multipart注解，参数通过@PartMap形式上传，注意，这里一定要用Map这样的格式，

也只能用RequestBody形式，本身retrofit是仅支持两种形式的String类型，这里的不在其中，故此不支持直接使用

String类型，必须转成RequestBody形式，附上转型方法

public static RequestBody toRequestBody(String value) {
    RequestBody requestBody = RequestBody.create(MediaType.parse("text/plain"), value);
    return requestBody;
}
 

完整代码

/**
 * @param callback
 * @return
 */
public static Call updateOneFile(Map type, File file, final ResultCallback> callback) {
 
    if (callback == null) throw new NullPointerException("callback == null");
    NRService mService = ServiceFactory.createNewService(NRService.class);
 
    RequestBody reqFile = RequestBody.create(MediaType.parse("image/*"), file);
    MultipartBody.Part body = MultipartBody.Part.createFormData("file", file.getName(), reqFile);
 
    String descriptionString = "image";
    RequestBody description = RequestBody.create(MediaType.parse("multipart/form-data"), descriptionString);
 
    Call> call = mService.updateOneFile(type, description, body);
    Callback> cbk = new Callback>() {
 
        @Override
        public void onResponse(Call> call, Response> response) {
            Result.onResponse(response, callback);
        }
 
        @Override
        public void onFailure(Call> call, Throwable t) {
            Result.onFailure(t, callback);
        }
    };
    call.enqueue(cbk);
    return call;
}