在AyncTask中解码BLOB，并将BLOB字符串作为参数传递

Question

Goal

My Goal here is to download an image from my server. HOWEVER, the image as a blob field will be stored in the database and not a link to the image.

What I have done

I actually had this downloading of image working but the path to the image was passed and that image was downloaded from the file. However, I am attempting to edit my code so it takes the Blob string (downloaded from the server)and loads this image. Below is my code.

What I think the problem is

My biggest issue is in the try I take my "blob" in as a string parameter. (IS that mistake number 1?) which is urldisplay. however , BitmapFactory.decodeStream() requires an InputStream. but if I change my parameter from a String to InputStream.

I get an error on the following code saying :cannot resolve method(java.lang.string)

 new DownloadImageTask(holder.imageview).execute(ArrayListStudents.get(position).getImage());

and if I change all my settings and getters of images to InputStream, I get an error where I call student.setImage(jRealObject.getString("cimage")); to get the data from the column on the "GetString"

private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
    ImageView bmImage;

    public DownloadImageTask(ImageView bmImage) {
        this.bmImage = bmImage;
    }

    protected Bitmap doInBackground(String... urls) {
        String urldisplay = urls[0];// this parameter once had url of image  

        //but now it has the image bitmap.
        Bitmap cImg1= null;
        try {
            InputStream in =  new java.net.URL(urldisplay).openStream();
            // cImg1= BitmapFactory.decodeStream(in);
            cImg1=urldisplay;//Assign strings to BitMap?
        } catch (Exception e) {
            Log.e("Error", e.getMessage());
            e.printStackTrace();
        }
        return cImg1;
    }  

    protected void onPostExecute(Bitmap result) {
        bmImage.setImageBitmap(result);
    }
}

Answer 1

Use this to decode your BLOB to bitmap :

protected Bitmap doInBackground(String... urls) {
    String urldisplay = urls[0];// this parameter once had url of image  
    Bitmap cImg1= null;
    try {
        byte[] byteArray = DBcursor.getBlob(urldisplay);  
        cImg1 = BitmapFactory.decodeByteArray(byteArray, 0 ,byteArray.length);
    } catch (Exception e) {
        Log.e("Error", e.getMessage());
        e.printStackTrace();
    }
    return cImg1;
}