如何在进度条上显示进度(Retrofit下载)

@Streaming
@GET("download/file")
Call<ResponseBody> downloadFile();

OkHttpClient.Builder builder = new OkHttpClient.Builder();
builder.addInterceptor(new DownloadProgressInterceptor(progressBar)); // 自定义的拦截器，用于获取下载进度
OkHttpClient client = builder.build();

Retrofit retrofit = new Retrofit.Builder()
        .baseUrl(BASE_URL)
        .client(client)
        .build();

ApiService apiService = retrofit.create(ApiService.class);
Call<ResponseBody> call = apiService.downloadFile();

call.enqueue(new Callback<ResponseBody>() {
    @Override
    public void onResponse(Call<ResponseBody> call, Response<ResponseBody> response) {
        if (response.isSuccessful()) {
            // 下载成功，保存文件到本地
            saveFile(response.body());
        } else {
            // 下载失败
            Toast.makeText(MainActivity.this, "下载失败", Toast.LENGTH_SHORT).show();
        }
    }

    @Override
    public void onFailure(Call<ResponseBody> call, Throwable t) {
        // 下载失败
        Toast.makeText(MainActivity.this, "下载失败", Toast.LENGTH_SHORT).show();
    }
});

public class DownloadProgressInterceptor implements Interceptor {
    private ProgressBar progressBar;

    public DownloadProgressInterceptor(ProgressBar progressBar) {
        this.progressBar = progressBar;
    }

    @Override
    public Response intercept(Chain chain) throws IOException {
        Response originalResponse = chain.proceed(chain.request());

        return originalResponse.newBuilder()
                .body(new DownloadProgressResponseBody(originalResponse.body(), progressBar))
                .build();
    }
}

public class DownloadProgressResponseBody extends ResponseBody {
    private ResponseBody responseBody;
    private ProgressBar progressBar;
    private BufferedSource bufferedSource;

    public DownloadProgressResponseBody(ResponseBody responseBody, ProgressBar progressBar) {
        this.responseBody = responseBody;
        this.progressBar = progressBar;
    }

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

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

    @Override
    public BufferedSource source() {
        if (bufferedSource == null) {
            bufferedSource = Okio.buffer(source(responseBody.source()));
        }
        return bufferedSource;
    }

    private Source source(Source source) {
        return new ForwardingSource(source) {
            long totalBytesRead = 0;

            @Override
            public long read(Buffer sink, long byteCount) throws IOException {
                long bytesRead = super.read(sink, byteCount);
                totalBytesRead += bytesRead != -1 ? bytesRead : 0;
                int progress = (int) ((totalBytesRead * 100) / responseBody.contentLength());
                // 更新进度条的显示
                progressBar.setProgress(progress);
                return bytesRead;
            }
        };
    }
}