无法通过RecyclerView从Firebase存储下载图像

Question

我正在编写一个代码，该代码通过recyclerView从Firebase存储下载图像并将其保存在内部存储中，但是无法保存在电话的内部存储中。

download_btn 按钮用于从Firebase下载图像。 storageReference 用于引用文件。 elementAddress 包含图像在recyclerView和图像URL中的位置。

代码如下：

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
private List<List_data>list_data;
private Context ct;
ProgressDialog progressDialog;
StorageReference storage;StorageReference fileRef;
Map<Integer,String> elementAddress = new HashMap<Integer, String>() ;

public MyAdapter(List<List_data> list_data, Context ct) {
    this.list_data = list_data;
    this.ct = ct;
}
@NonNull
@Override
public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    View view= LayoutInflater.from(parent.getContext()).inflate(R.layout.list_data,parent,false);
    return new ViewHolder(view);
}


@Override
public void onBindViewHolder(@NonNull final ViewHolder holder, final int position) {
     storage = FirebaseStorage.getInstance().getReference();
    final List_data ld=list_data.get(position);
    holder.tvname.setText(ld.getName());
     fileRef = storage.child(ld.getImgUrl());
    Log.i("CLICKED DATA",Integer.toString(position));

    elementAddress.put(position,ld.getImgUrl());

    final long ONE_MEGABYTE = 1024*1024*5;
    fileRef.getBytes(ONE_MEGABYTE).addOnSuccessListener(new OnSuccessListener<byte[]>() {
        @Override
        public void onSuccess(byte[] bytes) {
            Bitmap bitmap = BitmapFactory.decodeByteArray(bytes,0,bytes.length);
            holder.imageView.setImageBitmap(bitmap);
        }
    }).addOnFailureListener(new OnFailureListener() {
        @Override
        public void onFailure(@NonNull Exception e) {

        }
    });
}
@Override
public int getItemCount() {
    return list_data.size();
}



public class ViewHolder extends RecyclerView.ViewHolder{
    private ImageView imageView;
    private TextView tvname;
    private Button download_btn;
    public ViewHolder(View itemView) {
        super(itemView);
        imageView=(ImageView)itemView.findViewById(R.id.img_view);
        tvname=(TextView)itemView.findViewById(R.id.uName);
        download_btn = itemView.findViewById(R.id.download_pic_btn);
        //download_btn.setTag(123,itemView);



        download_btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Log.i("ITEM CLICKED",Integer.toString(getAdapterPosition()));
                StorageReference storageReference = storage.child(elementAddress.get(getAdapterPosition()));
                long ONE_MEGABYTE = 1024*1024*5;
                storageReference.getBytes(ONE_MEGABYTE).addOnSuccessListener(new OnSuccessListener<byte[]>() {
                    @Override
                    public void onSuccess(byte[] bytes) {
                        Bitmap bitmap = BitmapFactory.decodeByteArray(bytes,0,bytes.length);
                        ContextWrapper cw = new ContextWrapper(ct.getApplicationContext());
                        File directory = cw.getDir("imageDir",Context.MODE_PRIVATE);

                        if(!directory.exists()){
                            directory.mkdir();
                        }
                        File myPath = new File(directory,"image"+".jpg");
                        FileOutputStream fos=null;
                        try{
                          fos = new FileOutputStream(myPath.getAbsolutePath());
                          Log.i("PATH OF FILE", myPath.getAbsolutePath().toString());
                          bitmap.compress(Bitmap.CompressFormat.PNG,100,fos);
                        }catch (Exception e){
                            Log.i("ERROR WHILE UPLOADING",e.getMessage());
                            e.printStackTrace();
                        }finally {
                            try {
                                fos.flush();
                                fos.close();
                                Toast.makeText(ct.getApplicationContext(),"FILE DOWNLOADED",Toast.LENGTH_SHORT).show();
                            } catch (Exception e) {
                                e.printStackTrace();
                            }
                        }
                    }
                });
            }
        });
    }
}

}