Helper class to save images of type Bitmap to storage (Assumed that storage permission is already allowed)

ImageSaver.java

public class ImageSaver {

    public static void saveImage( Context context, String FILE_NAME, Bitmap bitmap){

        String savedImagePath = null;

        final File path = Environment.getExternalStoragePublicDirectory (Environment.DIRECTORY_DCIM + "/YOUR_DIRECTORY_NAME/");
        
        savedImagePath = path.getAbsolutePath();
        
        // check if already exists
        if(!path.exists()) path.mkdirs();

        final File file = new File(path, FILE_NAME + ".jpg");

        try
        {
            final FileOutputStream FOStream = new FileOutputStream(file);
            final BufferedOutputStream BOStream = new BufferedOutputStream(FOStream, 8192);

            bitmap.compress(Bitmap.CompressFormat.JPEG, 85, BOStream);
            BOStream.flush();
            BOStream.close();
        }
        catch (final IOException e) {e.printStackTrace();}

        // add & refresh the system gallery
        Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
        File f = new File(savedImagePath);
        Uri contentUri = Uri.fromFile(f);
        mediaScanIntent.setData(contentUri);
        context.sendBroadcast(mediaScanIntent);

    }
}

And from Activity/Fragment/Anywhere simply call :

ImageSaver.save(context, filename, resource)

where,

 context : Context
 filename : String
 resource : Bitmap

The below code is optional:

// add & refresh the system gallery
Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);
File f = new File(savedImagePath);
Uri contentUri = Uri.fromFile(f);
mediaScanIntent.setData(contentUri);
context.sendBroadcast(mediaScanIntent);

Use it^ whenever you need to refresh gallery So that when image is saved it can be viewed in gallery immediately