视频文件在恢复时损坏 在android中下载

Question

我正在下载视频文件，它工作正常并在成功下载后播放，但如果我暂停然后继续下载，那么它会成功下载剩余的文件，但它已损坏且无法播放视频

            Request.Builder builder = new Request.Builder();
            builder = builder.url(downloadFileUrl);

            builder = builder.addHeader("RANGE", "bytes=" + existLocalFileLength);
            Request request = builder.build();

            Call call = okHttpClient.newCall(request);
            Response response = call.execute();

            if (response != null && response.isSuccessful()) {
                RandomAccessFile downloadFile = new RandomAccessFile(existLocalFile, "rw");

                downloadFile.seek(existLocalFileLength);
                ResponseBody responseBody = response.body();
                InputStream inputStream = responseBody.byteStream();
                BufferedInputStream bufferedInputStream = new BufferedInputStream(inputStream);
                byte data[] = new byte[102400];
                long totalReadLength = 0;
                int readLength = bufferedInputStream.read(data);
                while (readLength != -1) {

                    if (getDownloadManager().isDownloadPaused()) {
                        ret = DOWNLOAD_PAUSED;
                        break;
                    } else if (getDownloadManager().isDownloadCanceled()) {
                        ret = DOWNLOAD_CANCELED;
                        break;
                    } else {

                        downloadFile.write(data, 0, readLength);

                        totalReadLength = totalReadLength + readLength;

                        int downloadProgress = (int) ((totalReadLength + existLocalFileLength) * 100 / downloadFileLength);

                        Log.d("download_progress", "download_progress..." + downloadProgress);                

                        }

                        readLength = bufferedInputStream.read(data);
                    }
                }

Answer 1

你使用了BufferedInputStream，它就是这样恢复的。您必须使用 DownloadManager.Request，这是一个示例。

private void startDownloading(String link) {    
            Uri uri = Uri.parse(link);
            downloadManager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE);
            DownloadManager.Request request = new DownloadManager.Request(uri);
            request.setAllowedNetworkTypes(DownloadManager.Request.NETWORK_WIFI |
                    DownloadManager.Request.NETWORK_MOBILE);
            request.setTitle(createPDFPath());
            request.allowScanningByMediaScanner();
            request.setDestinationInExternalPublicDir( Environment.DIRECTORY_DOWNLOADS, createPDFPath());
            request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
            request.setMimeType("application/mp4");
            reference_id = downloadManager.enqueue(request);    
    }