下载视频，然后在android VideoView上播放

Question

我需要对我的应用进行编程，以便首先从服务器下载视频并在播放之前将其保存到sdcard中。 我在哪里可以得到本教程？

目前，我正在播放视频，但我不想这样。

final VideoView videoView = (VideoView)rootView.findViewById(R.id.styleVideo);
        videoView.setVideoURI(Uri.parse(videoPath));
        videoView.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {

            public void onPrepared(MediaPlayer mp) {
                videoView.setBackground(mScarfBuffer.getDrawable(position));
            }
        });
        videoView.setMediaController(new MediaController(rootView.getContext()));
        videoView.requestFocus();
      videoView.start();

Answer 1

使用以下命令下载文件：

void downloadFile(){

    try {
        URL url = new URL(dwnload_file_path);
        HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();

        urlConnection.setRequestMethod("GET");
        urlConnection.setDoOutput(true);

        //connect
        urlConnection.connect();

        //set the path where we want to save the file           
        String SDCardRoot= Environment.getExternalStorageDirectory() ; 
        //create a new file, to save the downloaded file 
        File file = new File(SDCardRoot,"mydownloadmovie.mp4");

        FileOutputStream fileOutput = new FileOutputStream(file);

        //Stream used for reading the data from the internet
        InputStream inputStream = urlConnection.getInputStream();

        //this is the total size of the file which we are downloading
        totalSize = urlConnection.getContentLength();


        //create a buffer...
        byte[] buffer = new byte[1024];
        int bufferLength = 0;

        while ( (bufferLength = inputStream.read(buffer)) > 0 ) {
            fileOutput.write(buffer, 0, bufferLength);
            downloadedSize += bufferLength;
                 }
        //close the output stream when complete //
        fileOutput.close();

    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    catch (Exception e) {

    }       
}

不要忘记将其包装在AsyncTask中。
然后使用MediaPlayer播放您下载的文件（现在是本地文件）。

Answer 2

此代码下载完毕并播放视频

public class Testing extends AppCompatActivity {
    VideoView videoView;
MediaController mediaController;

@Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_testing);
        videoView = (VideoView) findViewById(R.id.vid258);
        mediaController = new MediaController(this);
// Enter Your Server Link 
final DownloadTask downloadTask = new DownloadTask(Testing.this);
        downloadTask.execute("http://codechair.com/video/1496139752333.mp4");
});
}
private class DownloadTask extends AsyncTask<String, Integer, String> {

        private Context context;
        private PowerManager.WakeLock mWakeLock;

        public DownloadTask(Context context) {
            this.context = context;
        }

        @Override
        protected String doInBackground(String... sUrl) {
            InputStream input = null;
            OutputStream output = null;
            HttpURLConnection connection = null;
            try {
                URL url = new URL(sUrl[0]);
                connection = (HttpURLConnection) url.openConnection();
                connection.connect();

                // expect HTTP 200 OK, so we don't mistakenly save error report
                // instead of the file
                if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {
                    return "Server returned HTTP " + connection.getResponseCode()
                            + " " + connection.getResponseMessage();
                }

                // this will be useful to display download percentage
                // might be -1: server did not report the length
                int fileLength = connection.getContentLength();

                // download the file
                input = connection.getInputStream();
                output = new FileOutputStream("/sdcard/file_name.mp4");

                byte data[] = new byte[4096];
                Log.d("Orignalvalu1",String.valueOf(new byte[4096]));
                long total = 0;
                int count;
                while ((count = input.read(data)) != -1) {
                    Log.d("Orignalvalu1",String.valueOf(input.read(data)));
                    // allow canceling with back button
                    if (isCancelled()) {
                        input.close();
                        return null;
                    }
                    total += count;
                    Log.d("Orignalvalu2",String.valueOf(total));
                    // publishing the progress....
                    if (fileLength > 0) // only if total length is known
                        publishProgress((int) (total * 100 / fileLength));
                    output.write(data, 0, count);
                }
            } catch (Exception e) {
                return e.toString();
            } finally {
                try {
                    if (output != null)
                        output.close();
                    if (input != null)
                        input.close();
                } catch (IOException ignored) {
                }

                if (connection != null)
                    connection.disconnect();
            }
            return null;
        }
        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            // take CPU lock to prevent CPU from going off if the user
            // presses the power button during download
            PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
            mWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK,
                    getClass().getName());
            mWakeLock.acquire();
            mProgressDialog.show();
        }

        @Override
        protected void onProgressUpdate(Integer... progress) {
            super.onProgressUpdate(progress);
            // if we get here, length is known, now set indeterminate to false
            mProgressDialog.setIndeterminate(false);
            mProgressDialog.setMax(100);
            mProgressDialog.setProgress(progress[0]);
        }

        @Override
        protected void onPostExecute(String result) {
            mWakeLock.release();
            mProgressDialog.dismiss();
            if (result != null)
                Toast.makeText(context,"Download error: "+result, Toast.LENGTH_LONG).show();
            else
                Toast.makeText(context,"File downloaded", Toast.LENGTH_SHORT).show();
            videoView.setVideoPath("/storage/emulated/0/file_name.mp4");
            videoView.setMediaController(mediaController);
            videoView.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                @Override
                public void onPrepared(MediaPlayer mp) {
                    mp.setLooping(true);
                }
            });
            videoView.requestFocus();
            videoView.start();
        }
    }