使用 Retrofit 1.8.0 的多部分请求不起作用

Question

我有 4 天的时间，尝试在 android 中使用 Retrofit 1.8.0 发出多部分请求并取得任何成功。我的界面看起来像这样

@Multipart
@POST("/posts/add.json") 
void addComment(
  @Part("id") String id,
  @Part("post[body]") String body,
  @Part("post[attachment]") TypedFile attachment,
  Callback<Map<String, String>> callback );

但是，在服务器端，我收到以下内容

Parameters: {"id"=># <File:/var/folders/z0/0ggjvvfj4t1fdsvbxf3lc9pw0000gn/T/RackMultipart9853-0>, "post"=>{"body"=>#<File:/var/folders/z0/0ggjvvfj4t1fdsvbxf3lc9pw0000gn/T/RackMultipart9853-1>, "attachment"=>#<File:/var/folders/z0/0ggjvvfj4t1fdsvbxf3lc9pw0000gn/T/RackMultipart9853-2>}, "controller"=>"posts", "action"=>"add", "format"=>"json"}

如您所见，文件部分在每个部分都发送它，但我缺少 id 和 post[body] 的参数值

这就是 Retrofit 试图发送的内容

 02-06 15:01:16.213    32545-822/com.myapp D/Retrofit﹕ --fe41634b-6826-4ee4-95cb-65efb0ca66c2
Content-Disposition: form-data; name="id"
Content-Type: text/plain; charset=UTF-8
Content-Length: 3
Content-Transfer-Encoding: binary
189
--fe41634b-6826-4ee4-95cb-65efb0ca66c2
Content-Disposition: form-data; name="post[body]"
Content-Type: text/plain; charset=UTF-8
Content-Length: 4
Content-Transfer-Encoding: binary
test
--fe41634b-6826-4ee4-95cb-65efb0ca66c2
Content-Disposition: form-data; name="post[attachment]"; filename="IMG_20140203_144358.jpg"
Content-Type: image/jpg
Content-Length: 1615460
Content-Transfer-Encoding: binary
����/�Exif����MM��*���������

这是 HttpMime 库在 Multipart 中发送的内容，不同之处在于针对 Retrofit 的“Content-Transfer-Encoding”标头

Content-Disposition: form-data; name="id"
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 8bit

Content-Disposition: form-data; name=“post[body]"
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 8bit

Content-Disposition: form-data; name=“post[attachment]"; filename="images.jpg"
Content-Type: image/jpg
Content-Transfer-Encoding: binary

有什么线索吗？提前致谢

------------------解决方案------------ ----------------------

最后，我以这种方式解决了，实际上我的答案非常接近@lazypig，这是一个很好的指导方针

我唯一改变的是他的类“ByteArrayTypedOutput”

我创建了一个名为“MultipartTypedOutputCustom”的类http://pastie.org/10549360

这就是我的界面现在的样子

“PostsRetrofitAPI.java”类

@POST("/posts/add.json")
    void addComment(@Body MultipartTypedOutputCustom parts,
                    Callback<Map<String, String>> callback);

“PostsService.java”类

//Properties
private PostsRetrofitAPI mApi;
...

    @Override
        public void addComment(ServiceResponseHandler<Map<String, String>> handler, String id, String body, TypedFile attachment) {
           MultipartTypedOutputCustom parts = new MultipartTypedOutputCustom();
           parts.addPart("id", new TypedString(id));
           parts.addPart("post[body]", new TypedString(body));
           parts.addPart("post[attachment]", attachment);
    objectRetrofitCallback= new ObjectRetrofitCallback(handler, ServerError.class, ClientError.class);
            mApi.addComment(parts, objectRetrofitCallback);
        }

Answer 1

如果您看到http://square.github.io/retrofit/ 上的示例，则“id”和“part[body]”参数的对象类型需要是 TypedString 而不是 String。 TypedString 设置适当的 MIME 类型并转换为字节：

https://github.com/square/retrofit/blob/master/retrofit/src/main/java/retrofit/mime/TypedString.java

Answer 2

我这样做是为了界面

interface MultipartFormDataService {
    @POST("/{uploadPath}")
    void multipartFormDataSend(
            @EncodedPath("uploadPath") String uploadPath,
            @Body MultipartTypedOutput multipartTypedOutput,
            Callback<String> cb);
}

然后当我调用它时，它看起来像这样

// creating the Multipart body using retrofit
MultipartTypedOutput multipartTypedOutput = new MultipartTypedOutput();
TypedString idParam = new TypedString("[ID Value]")
TypedString bodyParam = new TypedString("[Body text]")
ByteArrayTypedOutput byteMultipartTypedOut = new ByteArrayTypedOutput(bytes)

// add parts
multipartTypedOutput.addPart("id", idParam);
multipartTypedOutput.addPart("body", bodyParam);
multipartTypedOutput.addPart("attachment", extraParamTypedString);

// send
multipartService.multipartFormDataSend(
                "[TARGET URL]",
                multipartTypedOutput,
            aCallback);

我的 ByteArrayTypedOutput 很简单

public class ByteArrayTypedOutput implements TypedOutput {

    private MultipartFormMetadata metadata;
    private byte[] imageData;

    public ByteArrayTypedOutput(MultipartFormMetadata metadata, byte[] imageData)
        this.metadata = metadata;
        this.imageData = imageData;
    }

    @Override
    public String fileName() {
        return metadata.fileName;
    }

    @Override
    public String mimeType() {
        return metadata.fileMimeType;
    }

    @Override
    public long length() {
        return imageData.length;
    }

    @Override
    public void writeTo(OutputStream outputStream) throws IOException {
         outputStream.write(imageData);
    }
}

Answer 3

我今天发送文件和一些字段时遇到了类似的问题，这是我的解决方案

我的界面，TypedFile 是一个 Retrofit 类

    @Multipart
    @POST("/api/Media/add")
    void addMedia(@Part("file") TypedFile photo,
                  @Part("type") String type,
                  @Part("name") String name,
                  @Part("description") String description,
                  Callback<com.yourcompany.pojo.Media> callback);

在活动中

profileImage.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent galleryIntent = new Intent(
                    Intent.ACTION_PICK,
                    MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
            startActivityForResult(galleryIntent , RESULT_GALLERY );
        }
    });

然后

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    switch (requestCode) {
        case RESULT_GALLERY :
            if (null != data) {
                imageUri = data.getData();
                String selectedImagePath = null;
                Uri selectedImageUri = data.getData();
                Cursor cursor = activity.getContentResolver().query(selectedImageUri, null, null,
                null, null);
                if (cursor == null) {
                    selectedImagePath = imageUri.getPath();
                } else {
                    cursor.moveToFirst();
                    int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
                    selectedImagePath = cursor.getString(idx);
                }
                File file = new File(selectedImagePath);
                waiter.setVisibility(View.VISIBLE);
                _YOUR_APP_._YOUR_INTERFACE_.addMedia(new TypedFile("image/*", file), "avatar", "avatar", "avatar", new Callback<Media>() {

                    @Override
                    public void success(Media media, Response response) {

                    }

                    @Override
                    public void failure(RetrofitError error) {

                    }
                });
            }
            break;
        default:
            break;
    }
}

媒体类是保持答案的简单pojo

public class Media {

@Expose
private int[] data;

/**
 *
 * @return
 * The data
 */
public int getData() {
    return data[0];
}

/**
 *
 * @param data
 * The data
 */
public void setData(int[] data) {
    this.data = data;
}

}