位图获取空值android

Question

在这段代码中我得到了null-value bitmap如何解决这个错误，并且后执行方法位图也是null，所以请帮我获取位图的正确值。我正在使用解析此应用程序

@Override
    protected void onPreExecute() {
        super.onPreExecute();
        progressDialog.show();
    }

    @Override
    protected Bitmap doInBackground(String... params) {
        try {
            return Picasso.with(context).load(params[0]).get();

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


    @Override
    protected void onPostExecute(Bitmap bitmap) {
        super.onPostExecute(bitmap);
        try {
            if(bitmap==null)
            {
                Toast.makeText(context,"bitmap null",Toast.LENGTH_SHORT);
            }

            this.imageSaveListener.onImageSaved(bitmap);
        }catch (Exception e){
            Log.d(TAG, "Error saving file: " + e.getMessage());
        }
    }

    public void hideProgressDialog(){
        if (progressDialog != null && progressDialog.isShowing()) {
            progressDialog.dismiss();
        }
    }
}

public interface ImageSaveListener {

    void onImageSaved(Bitmap downloadImageBitmap);

}