How to download file/image from url to your android app

Question

I need my android app to make request to url to download an image from this url so I have built this class to help me, BUT it didn\'t work ???

public class M         


        

Answer 1

Define these on the top side

Button BtnDownload;

DownloadManager downloadManager;

After, You should write on create inside :

BtnDownload = (Button)findViewById(R.id.button1);

Later, You should write to the button's click event

downloadManager = (DownloadManager)getSystemService(Context.DOWNLOAD_SERVICE);

Uri uri = Uri.parse("your url");

DownloadManager.Request request = new DownloadManager.Request(uri);
                request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);

Long reference = downloadManager.enqueue(request);

Finally, you need to add this onto the application tag to the manifest.xml :

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

Answer 2

The problem with your code is you have not read the InputStream. You should try this

Bitmap bitmap = BitmapFactory.decodeStream(is); 
return bitmap;

and make the Asynctask return type as Bitmap. Or, As you have used that is in postExecute() your doInBackground() should return that InputStream object is. But you are returning void.

Okey.Try this edited Asynctask.

    private  class MyAsnyc extends  AsyncTask <Void,Void,File> {
    File file;
    @Override 
    protected File doInBackground( Void... params ) { 
        InputStream is = null;
        File path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
        file = new File( path , "Demo Picture.jpg" ) ;  
        try { // Make sure the Pictures directory exists.path.mkdirs() ; URL url = new URL ( "http: / /androidsaveitem .appspot.com/download.jpg") ; URLConnection ucon = url.openConnection ( ) ; 
            path.mkdirs();

            OutputStream os = new FileOutputStream(file) ; 
            byte [ ] data = new byte [ is.available ( ) ] ;
            is.read ( data ) ; os.write (data );is.close ( ) ; os.close ( ) ; 
            return file;
        }
        catch (Exception e){ 
            Log .d ( "ImageManager " , " Error: " + e ) ;
        }           

        return null;
    }
    protected void onPostExecute (File file) {
        try{
            MediaScannerConnection.scanFile( null , new String [] {file.toString( ) } , null , new MediaScannerConnection.OnScanCompletedListener ( ) { public void onScanCompleted (String path, Uri uri) { 
                Log.i ( " External Storage" , " Scanned " + path + " : " ) ; Log.i ( " E x t e r n a l S t o r a g e " , " - > u r i = " + uri ) ; } } ) ;
        }catch (Exception e) {
            // TODO: handle exception
        }
    }}

Answer 3

new DownloadImageFromUrlTask().execute(imagePath);

//add glide dependency in app gradle file
compile 'com.github.bumptech.glide:glide:3.7.0'

public class DownloadImageFromUrlTask extends AsyncTask<String, Void, Bitmap> {
        String downloadPath = "";

        @Override
        protected Bitmap doInBackground(String... args) {
            try {
                downloadPath = args[0];
                return BitmapFactory.decodeStream((InputStream) new URL(downloadPath).getContent());

            } catch (IOException e) {
                e.printStackTrace();
            }
            return null;
        }

        @Override
        protected void onPostExecute(Bitmap bitmap) {
            if (bitmap != null) {
                String photoFileName = downloadPath.substring(downloadPath.lastIndexOf('/') + 1);
                String root_Path =  Environment.getExternalStorageDirectory().toString();

                String saveImagePath = root_Path + "/" + photoFileName;

                saveBitmapToJPEGFile(MainActivity.this, bitmap, new File(saveImagePath), 900);
                loadImageWithGlide(MainActivity.this, myImageView, saveImagePath);
            } else {
                myImageView.setImageResource(R.drawable.default_photo);
            }
        }
    }

    public static Boolean saveBitmapToJPEGFile(Context ctx, Bitmap theTempBitmap, File theTargetFile, int i) {
        Boolean result = true;
        if (theTempBitmap != null) {
            FileOutputStream out = null;
            try {
                out = new FileOutputStream(theTargetFile);
                theTempBitmap.compress(Bitmap.CompressFormat.JPEG, CommonUtils.JPEG_COMPRESION_RATIO_DEFAULT, out);    //kdfsJpegCompressionRatio
            } catch (FileNotFoundException e) {
                result = false;
                e.printStackTrace();
            }
            if (out != null) {
                try {
                    out.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        } else {
            result = false;
        }
        return result;
    }

    public static void loadImageWithGlide(Context theCtx, ImageView theImageView, String theUrl) {
        Glide.with(theCtx)
                .load(theUrl)
                .diskCacheStrategy(DiskCacheStrategy.NONE)
                .skipMemoryCache(true)
                .into(theImageView);

    }

Answer 4

try this

public class MyAsnyc extends AsyncTask<Void, Void, Void> {
    public static File file;
    InputStream is;

    protected void doInBackground() throws IOException {

        File path = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
        file = new File(path, "DemoPicture.jpg");
        try {    
            // Make sure the Pictures directory exists.
            path.mkdirs();

            URL url = new URL("http://androidsaveitem.appspot.com/downloadjpg");
            /* Open a connection to that URL. */
            URLConnection ucon = url.openConnection();

            /*
             * Define InputStreams to read from the URLConnection.
             */
            is = ucon.getInputStream();

            OutputStream os = new FileOutputStream(file);
            byte[] data = new byte[is.available()];
            is.read(data);
            os.write(data);
            is.close();
            os.close();

        } catch (IOException e) {
            Log.d("ImageManager", "Error: " + e);
        }
    }

    @Override
    protected Void doInBackground(Void... params) {
        // TODO Auto-generated method stub
        try {
            doInBackground();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        return null;
    }

    protected void onPostExecute() {
        try {
            // Tell the media scanner about the new file so that it is
            // immediately available to the user.
            MediaScannerConnection.scanFile(null,
                    new String[]{file.toString()}, null,
                    new MediaScannerConnection.OnScanCompletedListener() {
                        public void onScanCompleted(String path, Uri uri) {
                            Log.i("ExternalStorage", "Scanned " + path + ":");
                            Log.i("ExternalStorage", "-> uri=" + uri);
                        }
                    });
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }
}