如何使用OkHTTP3/Retrofit2 2获取分块多文件上传的进度？

OkHttp3和Retrofit2是Android开发中常用的网络请求库，可以用于实现分块多文件上传功能。要获取分块多文件上传的进度，可以通过自定义RequestBody和Interceptor来实现。

首先，我们需要自定义一个ProgressRequestBody类，继承自RequestBody，并重写其中的方法。在该类中，我们可以通过实现okhttp3.RequestBody的writeTo(BufferedSink sink)方法来监听上传进度，并通过回调方式将进度信息传递给外部。

public class ProgressRequestBody extends RequestBody {
    private static final int DEFAULT_BUFFER_SIZE = 2048;

    private File file;
    private String contentType;
    private UploadCallbacks callbacks;

    public interface UploadCallbacks {
        void onProgressUpdate(int percentage);
    }

    public ProgressRequestBody(File file, String contentType, UploadCallbacks callbacks) {
        this.file = file;
        this.contentType = contentType;
        this.callbacks = callbacks;
    }

    @Override
    public MediaType contentType() {
        return MediaType.parse(contentType);
    }

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

    @Override
    public void writeTo(BufferedSink sink) throws IOException {
        try (Source source = Okio.source(file)) {
            Buffer buffer = new Buffer();
            long uploaded = 0;
            long fileSize = file.length();
            for (long readCount; (readCount = source.read(buffer, DEFAULT_BUFFER_SIZE)) != -1; ) {
                sink.write(buffer, readCount);
                uploaded += readCount;
                int progress = (int) ((uploaded * 100) / fileSize);
                callbacks.onProgressUpdate(progress);
            }
        }
    }
}

接下来，我们可以使用Retrofit2来进行分块多文件上传。在Retrofit的接口定义中，我们需要使用@Multipart注解来标记上传文件的请求，并使用@Part注解来指定文件的参数名。

public interface FileUploadService {
    @Multipart
    @POST("upload")
    Call<ResponseBody> uploadFile(@Part("file") ProgressRequestBody file);
}

然后，我们可以创建一个OkHttpClient，并添加一个Interceptor来监听上传进度。在Interceptor中，我们可以通过RequestBody的contentLength()方法获取文件的总大小，并在写入请求体时更新上传进度。

OkHttpClient client = new OkHttpClient.Builder()
        .addInterceptor(new Interceptor() {
            @Override
            public Response intercept(Chain chain) throws IOException {
                Request originalRequest = chain.request();
                Request.Builder requestBuilder = originalRequest.newBuilder();

                if (originalRequest.body() instanceof ProgressRequestBody) {
                    ProgressRequestBody progressRequestBody = (ProgressRequestBody) originalRequest.body();
                    progressRequestBody.setUploadCallbacks(new ProgressRequestBody.UploadCallbacks() {
                        @Override
                        public void onProgressUpdate(int percentage) {
                            // 更新上传进度
                            Log.d("Upload Progress", percentage + "%");
                        }
                    });
                    requestBuilder.method(originalRequest.method(), progressRequestBody);
                }

                Request request = requestBuilder.build();
                return chain.proceed(request);
            }
        })
        .build();

最后，我们可以使用Retrofit来创建文件上传的请求，并将自定义的ProgressRequestBody作为参数传入。

Retrofit retrofit = new Retrofit.Builder()
        .baseUrl("http://example.com/")
        .client(client)
        .build();

File file = new File("path/to/file");
ProgressRequestBody requestBody = new ProgressRequestBody(file, "image/jpeg", new ProgressRequestBody.UploadCallbacks() {
    @Override
    public void onProgressUpdate(int percentage) {
        // 更新上传进度
        Log.d("Upload Progress", percentage + "%");
    }
});

FileUploadService service = retrofit.create(FileUploadService.class);
Call<ResponseBody> call = service.uploadFile(requestBody);
call.enqueue(new Callback<ResponseBody>() {
    @Override
    public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
        // 处理上传成功的响应
    }

    @Override
    public void onFailure(Call<ResponseBody> call, Throwable t) {
        // 处理上传失败的情况
    }
});

通过以上步骤，我们就可以使用OkHttp3和Retrofit2来实现分块多文件上传，并获取上传进度。在自定义的ProgressRequestBody中，我们可以根据需要进行进一步的处理，例如将进度信息传递给UI界面进行展示。

腾讯云相关产品推荐：