Веб-просмотр Android: загрузка файлов, таких как браузеры

Ответ 1

Наконец, я решил искать DownloadHandler из кода Android Stock Browser. Единственным заметным недостатком моего кода было cookie (!!!).

Здесь моя последняя рабочая версия (метод DownloadManager):

    wv.setDownloadListener(new DownloadListener() {
        @Override
        public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimeType, long contentLength) {
            DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));

            request.setMimeType(mimeType);
            //------------------------COOKIE!!------------------------
            String cookies = CookieManager.getInstance().getCookie(url);
            request.addRequestHeader("cookie", cookies);
            //------------------------COOKIE!!------------------------
            request.addRequestHeader("User-Agent", userAgent);
            request.setDescription("Downloading file...");
            request.setTitle(URLUtil.guessFileName(url, contentDisposition, mimeType));
            request.allowScanningByMediaScanner();
            request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
            request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, URLUtil.guessFileName(url, contentDisposition, mimeType));
            DownloadManager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
            dm.enqueue(request);
            Toast.makeText(getApplicationContext(), "Downloading File", Toast.LENGTH_LONG).show();
        }
    });

Ответ 2

wv.setDownloadListener(new DownloadListener() {
    @Override
    public void onDownloadStart(String url, String userAgent, String 
    contentDisposition, String mimeType, long contentLength) {
        DownloadManager.Request request = new 
    DownloadManager.Request(Uri.parse(url));

        request.setMimeType(mimeType);
        //------------------------COOKIE!!------------------------
        String cookies = CookieManager.getInstance().getCookie(url);
        request.addRequestHeader("cookie", cookies);
        //------------------------COOKIE!!------------------------
        request.addRequestHeader("User-Agent", userAgent);
        request.setDescription("Downloading file...");
        request.setTitle(URLUtil.guessFileName(url, contentDisposition, mimeType));
        request.allowScanningByMediaScanner();
        request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
        request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, URLUtil.guessFileName(url, contentDisposition, mimeType));
        DownloadManager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
        dm.enqueue(request);
        Toast.makeText(getApplicationContext(), "Downloading File", Toast.LENGTH_LONG).show();
    }
});

спасибо j.c за ваш ответ вы пропустили ); в конце кода.

Ответ 3

С помощью этой опции мне удалось загрузить полные файлы, загрузка работала с другими опциями, но документы выглядели пустыми, особенно при использовании сеанса.

Добавьте строки ниже к AndroidManifest.xml

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

Добавьте DownloadListener в свой WebView

Попробуйте этот код

wv.setDownloadListener(new DownloadListener() {
    @Override
    public void onDownloadStart(final String url, final String userAgent, String contentDisposition, String mimetype, long contentLength) {
        //Checking runtime permission for devices above Marshmallow.
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (checkSelfPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE)
                    == PackageManager.PERMISSION_GRANTED) {
                Log.v(TAG, "Permission is granted");
                downloadDialog(url, userAgent, contentDisposition, mimetype);

            } else {

                Log.v(TAG, "Permission is revoked");
                //requesting permissions.
                ActivityCompat.requestPermissions(PortalActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);

            }
        } else {
            //Code for devices below API 23 or Marshmallow
            Log.v(TAG, "Permission is granted");
            downloadDialog(url, userAgent, contentDisposition, mimetype);

        }
    }
});

//downloadDialog Method

public void downloadDialog(final String url, final String userAgent, String contentDisposition, String mimetype) {
    //getting filename from url.
    final String filename = URLUtil.guessFileName(url, contentDisposition, mimetype);
    //alertdialog
    AlertDialog.Builder builder = new AlertDialog.Builder(this);

    //title of alertdialog
    builder.setTitle(R.string.download_title);
    //message of alertdialog
    builder.setMessage(getString(R.string.download_file) + ' ' + filename);
    //if Yes button clicks.

    builder.setPositiveButton(getString(R.string.yes), new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            //DownloadManager.Request created with url.
            DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));
            //cookie
            String cookie = CookieManager.getInstance().getCookie(url);
            //Add cookie and User-Agent to request
            request.addRequestHeader("Cookie", cookie);
            request.addRequestHeader("User-Agent", userAgent);
            //file scanned by MediaScannar
            request.allowScanningByMediaScanner();
            //Download is visible and its progress, after completion too.
            request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
            //DownloadManager created
            DownloadManager downloadManager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
            //Saving files in Download folder
            request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, filename);
            //download enqued
            downloadManager.enqueue(request);
        }
    });
    builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            //cancel the dialog if Cancel clicks
            dialog.cancel();
            mWebView.goBack();
        }

    });
    //alertdialog shows.
    builder.show();

}

Ответ 4

AsyncTask для ручной загрузки имени файла (вы можете добавить к этому классу дополнительный код):

private static class getFileNameAsync extends AsyncTask<String, Void, String> {

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected String doInBackground(String... params) {
        URL url;
        String filename = null;
        HttpURLConnection conn = null;
        try {
            url = new URL(params[0]);
            conn = (HttpURLConnection) url.openConnection();
            conn.connect();
            conn.setInstanceFollowRedirects(false);

            try {
                for(int i = 0; i < 100; i++)
                {
                    String stringURL = conn.getHeaderField("Location");
                    if (stringURL != null) {
                        url = new URL(stringURL);
                        conn = (HttpURLConnection) url.openConnection();
                        conn.connect();
                        conn.setInstanceFollowRedirects(false);
                    } else {
                        i = 100;
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
            }

            String depo = conn.getHeaderField("Content-Disposition");
            if (depo != null) {
                String depoSplit[] = depo.split(";");
                int size = depoSplit.length;
                for(int i = 0; i < size; i++)
                {
                    if(depoSplit[i].startsWith("filename="))
                    {
                        filename = depoSplit[i].replaceFirst("(?i)^.*filename=\"?([^\"]+)\"?.*$", "$1").trim();
                        i = size;
                    }
                }
            }
        } catch (MalformedURLException e){
            e.printStackTrace();
        } catch (ProtocolException e){
            e.printStackTrace();
        } catch (FileNotFoundException e){
            e.printStackTrace();
        } catch (IOException e){
            e.printStackTrace();
        } catch (Exception e){
            e.printStackTrace();
        } finally {
            if (conn != null)
                conn.disconnect();
        }
        return filename;
    }
    @Override
    protected void onPostExecute(String filename) {
        super.onPostExecute(filename);
    }
}

DownloadListener (стабильная версия, не меняйте его):

    mWebView.setDownloadListener(new DownloadListener() {
        @Override
        public void onDownloadStart(String url,
                                    String userAgent,
                                    String contentDisposition,
                                    String mimetype,
                                    long contentLength) {
            if(Build.VERSION.SDK_INT >=23){
                Context nContext = MainActivity.this.getApplicationContext();
                if(nContext.checkSelfPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED){
                    MainActivity.this.requestPermissions(new String[]{android.Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
                    return;
                }
            }

            String fileName = "";
            url = url.replace(" ", "%20");

            AsyncTask<String, Void, String> asyncTask = new getFileNameAsync();
            asyncTask.execute(url);

            try {
                fileName = asyncTask.get();
            } catch (InterruptedException e) {
                e.printStackTrace();
            } catch (ExecutionException e) {
                e.printStackTrace();
            } catch (CancellationException e) {
                e.printStackTrace();
            }
            if ((fileName == null) || (fileName.hashCode() == "".hashCode())) {
                fileName = URLUtil.guessFileName(url, contentDisposition, mimetype);
            }

            DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));

            request.setMimeType(mimetype);
            String cookies = CookieManager.getInstance().getCookie(url);
            request.addRequestHeader("Cookie", cookies);
            request.addRequestHeader("User-Agent", userAgent);
            request.setDescription("Downloading File");
            request.setTitle(fileName);
            request.allowScanningByMediaScanner();
            request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
            request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, fileName);
            DownloadManager downloadManager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
            if (downloadManager != null) {
                downloadManager.enqueue(request);
            }
            Toast.makeText(getApplicationContext(), "Downloading File", Toast.LENGTH_LONG).show();
        }
    });