How to download blob url in webview

Question

I'm using a web view on Android. When I clicked the download button, url : "blob:http://tftpblah~.com/adljk" But I can't download it.

I searched and found that the solution is converting base64 using JavaScript. But it doesn't solve this problem...

Please help me

Answer 1

i used this code in my project and is worked for me, try it!

and don't forget to add this code to onCreateView function

1 -

webView.getSettings().setDefaultTextEncodingName("utf-8");
webView.addJavascriptInterface(new JavaScriptInterface(getContext()), "Android");

2 - Code:

public class JavaScriptInterface {
    private static String fileMimeType;
    private final Context context;
    public JavaScriptInterface(Context context) {
        this.context = context;
    }

    @JavascriptInterface
    public void getBase64FromBlobData(String base64Data) throws IOException {
        convertBase64StringToFileAndStoreIt(base64Data);
    }

    public static String getBase64StringFromBlobUrl(String blobUrl,String mimeType) {
        if(blobUrl.startsWith("blob")){
            fileMimeType = mimeType;
            return "javascript: var xhr = new XMLHttpRequest();" +
                    "xhr.open('GET', '"+ blobUrl +"', true);" +
                    "xhr.setRequestHeader('Content-type','" + mimeType +";charset=UTF-8');" +
                    "xhr.responseType = 'blob';" +
                    "xhr.onload = function(e) {" +
                    "    if (this.status == 200) {" +
                    "        var blobFile = this.response;" +
                    "        var reader = new FileReader();" +
                    "        reader.readAsDataURL(blobFile);" +
                    "        reader.onloadend = function() {" +
                    "            base64data = reader.result;" +
                    "            Android.getBase64FromBlobData(base64data);" +
                    "        }" +
                    "    }" +
                    "};" +
                    "xhr.send();";
        }
        return "javascript: console.log('It is not a Blob URL');";
    }
    private void convertBase64StringToFileAndStoreIt(String base64PDf) throws IOException {
        final int notificationId = 1;
        String currentDateTime = DateFormat.getDateTimeInstance().format(new Date());
        String newTime = currentDateTime.replaceFirst(", ","_").replaceAll(" ","_").replaceAll(":","-");
        Log.d("fileMimeType ====> ",fileMimeType);
        MimeTypeMap mimeTypeMap = MimeTypeMap.getSingleton();
        String extension = mimeTypeMap.getExtensionFromMimeType(fileMimeType);
        final File dwldsPath = new File(Environment.getExternalStoragePublicDirectory(
                Environment.DIRECTORY_DOWNLOADS) + "/" + newTime + "_." + extension);
        String regex = "^data:" + fileMimeType + ";base64,";
        byte[] pdfAsBytes = Base64.decode(base64PDf.replaceFirst(regex, ""), 0);
        try {
            FileOutputStream os = new FileOutputStream(dwldsPath);
            os.write(pdfAsBytes);
            os.flush();
            os.close();
        } catch (Exception e) {
            Toast.makeText(context, "FAILED TO DOWNLOAD THE FILE!", Toast.LENGTH_SHORT).show();
            e.printStackTrace();
        }
        if (dwldsPath.exists()) {
            Intent intent = new Intent();
            intent.setAction(android.content.Intent.ACTION_VIEW);
            Uri apkURI = FileProvider.getUriForFile(context,context.getApplicationContext().getPackageName() + ".provider", dwldsPath);
            intent.setDataAndType(apkURI, MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension));
            intent.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
            PendingIntent pendingIntent = PendingIntent.getActivity(context,1, intent, PendingIntent.FLAG_CANCEL_CURRENT);
            String CHANNEL_ID = "MYCHANNEL";
            final NotificationManager notificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
            NotificationChannel notificationChannel= new NotificationChannel(CHANNEL_ID,"name", NotificationManager.IMPORTANCE_LOW);
            Notification notification = new Notification.Builder(context,CHANNEL_ID)
                    .setContentText("You have got something new!")
                    .setContentTitle("File downloaded")
                    .setContentIntent(pendingIntent)
                    .setChannelId(CHANNEL_ID)
                    .setSmallIcon(android.R.drawable.stat_sys_download_done)
                    .build();
            if (notificationManager != null) {
                notificationManager.createNotificationChannel(notificationChannel);
                notificationManager.notify(notificationId, notification);
            }
        }
        Toast.makeText(context, "FILE DOWNLOADED!", Toast.LENGTH_SHORT).show();
    }
}