android - 如何从android中的服务器下载视频

Question

我正在做从服务器下载视频并播放从 sdcard 下载的视频的应用程序。

我在网站上有一个 .MP4 格式的视频文件和从服务器下载的视频，应该保存在 sdcard 中。

我的问题是如何从服务器下载视频。请给我一些想法和例子。

请帮我。

Answer 1

Android 自带 HTTPClient。您应该能够从HTTPClient 网站获得所需的所有信息。

示例： http ://hc.apache.org/httpcomponents-client-ga/examples.html

Android API 文档：http: //developer.android.com/reference/org/apache/http/client/package-summary.html

Answer 2

使用 AsyncTask 从 android 中的服务器下载 MP4 视频

public class CheckForSDCard {
//Check If SD Card is present or not method
public static boolean isSDCardPresent() {
    if (Environment.getExternalStorageState().equals(

            Environment.MEDIA_MOUNTED)) {
        return true;
    }
    return false;
}}

---

if (CheckForSDCard.isSDCardPresent()) {

                    //check if app has permission to write to the external storage.
                    if (EasyPermissions.hasPermissions(context, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
                        //Get the URL entered
                        url =videolist.get(i).optString("video") ;
                        new DownloadFile().execute(url);

                    } else {
                        //If permission is not present request for the same.
                       Utils.checkAndRequestPermissions(getActivity());
                    }


                } else {
                    Toast.makeText(getActivity(),
                            "SD Card not found", Toast.LENGTH_LONG).show();

                }

---

 private class DownloadFile extends AsyncTask<String, String, String> {


    private String fileName;
    private String folder;
    private boolean isDownloaded;
    File directory;

    /**
     * Before starting background thread
     * Show Progress Bar Dialog
     */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();

        Utils.show(getActivity(),"Downloading Started");
    }

    /**
     * Downloading file in background thread
     */
    @Override
    protected String doInBackground(String... f_url) {
        int count;
        try {
            URL url = new URL(f_url[0]);
            URLConnection connection = url.openConnection();
            connection.connect();
            // getting file length
            int lengthOfFile = connection.getContentLength();


            // input stream to read file - with 8k buffer
            InputStream input = new BufferedInputStream(url.openStream(), 8192);

            //String timestamp = new SimpleDateFormat("yyyy.MM.dd.HH.mm.ss").format(new Date());

            //Extract file name from URL
            fileName = f_url[0].substring(f_url[0].lastIndexOf('/') + 1, f_url[0].length());

            //Append timestamp to file name
            fileName = fileName;

            //External directory path to save file

            folder = Environment.getExternalStorageDirectory() + File.separator + "Internal Storage/DCIM/Camera/";

            //Create androiddeft folder if it does not exist
            directory = new File(folder);

            if (!directory.exists()) {
                directory.mkdirs();
            }

            // Output stream to write file
            OutputStream output = new FileOutputStream(folder + fileName);

            byte data[] = new byte[1024];

            long total = 0;

            while ((count = input.read(data)) != -1) {
                total += count;
                // publishing the progress....
                // After this onProgressUpdate will be called
                publishProgress("" + (int) ((total * 100) / lengthOfFile));
                Log.d(TAG, "Progress: " + (int) ((total * 100) / lengthOfFile));

                // writing data to file
                output.write(data, 0, count);
            }

            // flushing output
            output.flush();

            // closing streams
            output.close();
            input.close();
            return "Downloaded at: " + folder + fileName;

        } catch (Exception e) {
            Log.e("Error: ", e.getMessage());
        }

        return "Something went wrong";
    }

    /**
     * Updating progress bar
     */
    protected void onProgressUpdate(String... progress) {
        // setting progress percentage

    }


    @Override
    protected void onPostExecute(String message) {
        // dismiss the dialog after the file was downloaded
        getActivity().sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(directory)));
        // Display File path after downloading
        Toast.makeText(getActivity(),
                "Downloaded Successfully", Toast.LENGTH_LONG).show();
    }
}