Android改型2 JSON对象上载进度百分比

我使用改型2将JSON上传到服务器。JSON有一些BASE64编码的图像，因此上传整个图像需要时间。我想看看上传的百分比。我已经找到了现有文件的解决方案，但这不是一个文件，服务器只接受此表单。

对于其他有相同问题的人，我已经从这个库中改编了一个帮助器类（ProgressOutputStream）：我的工作代码如下：（用于上传文件，也用于上传json）

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import java.io.IOException;
import java.io.OutputStream;

class ProgressOutputStream extends OutputStream {
    private final OutputStream stream;
    private final UploadProgressRequestBody.ProgressListener listener;

    private long total;
    private long totalWritten;

    ProgressOutputStream(OutputStream stream, UploadProgressRequestBody.ProgressListener listener, long total) {
        this.stream = stream;
        this.listener = listener;
        this.total = total;
    }

    @Override
    public void write(byte[] b, int off, int len) throws IOException {
        this.stream.write(b, off, len);
        if (this.total < 0) {
            this.listener.update(-1, -1);
            return;
        }
        if (len < b.length) {
            this.totalWritten += len;
        } else {
            this.totalWritten += b.length;
        }
        this.listener.update(this.totalWritten, this.total);
    }

    @Override
    public void write(int b) throws IOException {
        this.stream.write(b);
        if (this.total < 0) {
            this.listener.update(-1, -1);
            return;
        }
        this.totalWritten++;
        this.listener.update(this.totalWritten, this.total);
    }

    @Override
    public void close() throws IOException {
        if (this.stream != null) {
            this.stream.close();
        }
    }

    @Override
    public void flush() throws IOException {
        if (this.stream != null) {
            this.stream.flush();
        }
    }
}

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

            if (originalRequest.body() == null) {
                return chain.proceed(originalRequest);
            }

            Request progressRequest = originalRequest.newBuilder()
                    .method(originalRequest.method(),
                            new UploadProgressRequestBody(originalRequest.body()))
                    .build();

            return chain.proceed(progressRequest);
        }
    }).build();

Retrofit retrofit = new Retrofit.Builder()
        .baseUrl(baseUrl)
        .client(client)
        .addConverterFactory(GsonConverterFactory.create())
        .build();

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

            if (originalRequest.body() == null) {
                return chain.proceed(originalRequest);
            }

            Request progressRequest = originalRequest.newBuilder()
                    .method(originalRequest.method(),
                            new UploadProgressRequestBody(originalRequest.body()))
                    .build();

            return chain.proceed(progressRequest);
        }
    }).build();

Retrofit retrofit = new Retrofit.Builder()
        .baseUrl(baseUrl)
        .client(client)
        .addConverterFactory(GsonConverterFactory.create())
        .build();