How can i convert String to Bitmap image on Java

There is a bitmap codes in the text file. I need to convert these codes as String to Bitmap and display them to the user on the screen. I wrote a code like below, but decodedByte is null. Where am I making a mistake?

try {
   BufferedReader reader = Files.newBufferedReader(Paths.get("/data/user/0/com.example.lockertestapplication/files/text.txt"), StandardCharsets.UTF_8);
   StringBuilder data = new StringBuilder();
   String line;
   while ((line = reader.readLine()) != null) {
      data.append(line);
   }
   reader.close();
   String text = data.toString();
   byte[] decodedString = Base64.decode(text, Base64.DEFAULT);
   Bitmap decodedByte = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);
   img.setImageBitmap(decodedByte);
                
} catch (IOException e) {
   e.printStackTrace();
}

Issue might be in removing Base64 identifier from Base64 encoded text. First, we need to split our Base64 string to get rid of the first part before “,”(comma)

String text = base64String.split(",")[1];

And then you are good to with your implemented method

byte[] decodedString = Base64.decode(base64Image, Base64.DEFAULT);
Bitmap decodedByte = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);
imageView.setImageBitmap(decodedByte);