Make upload method return String "the uploaded file url"

Question

I'm uploading an image to Firebase Storage, I need the image URL in the Storage to use it then to insert it within a document in FireStore. How to get the url after the upload process is finished and not before it finished?

   public String uploadImage(byte[] bytes) {
        try {
            final StorageReference ref = storage.child("images/" + new Date().toString());
            ref.putBytes(bytes)
                    .addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
                        @Override
                        public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                            ref.getDownloadUrl().addOnSuccessListener(new OnSuccessListener<Uri>() {
                                @Override
                                public void onSuccess(Uri uri) {
                                    res = uri.toString();
                                    return;
                                }
                            });
                        }
                    });
            System.out.println("RES : " + res);
            return res;
        }catch (NullPointerException e){
            return null;
        }
    }

//the variable res must return a not null value.

score 1 · Accepted Answer · answered Apr 13 '19 at 12:08

Ref :: Image not retrieving from Firebase

//add file on Firebase and got Download Link
filePath.putFile(imageUri).continueWithTask(new Continuation<UploadTask.TaskSnapshot, Task<Uri>>() {
    @Override
    public Task<Uri> then(@NonNull Task<UploadTask.TaskSnapshot> task) throws Exception {
        if (!task.isSuccessful()){
            throw task.getException();
        }
        return filePath.getDownloadUrl();
    }
}).addOnCompleteListener(new OnCompleteListener<Uri>() {
    @Override
    public void onComplete(@NonNull Task<Uri> task) {
        if (task.isSuccessful()){
            Uri downUri = task.getResult();
            Log.d(TAG, "onComplete: Url: "+ downUri.toString());
        }
    }
});

yes exactly, but it returns null because the upload process has not finished yet — Monƶer Al-Ħusaini, Apr 14 '19 at 06:36

Amr Jyniat · Answer 2 · 2019-04-13T12:17:55.683

0

we can get the URL of a file from taskSnapshot, like that:

public String uploadImage(byte[] bytes) {
    try {
        final StorageReference ref = storage.child("images/" + new Date().toString());
        ref.putBytes(bytes)
                .addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
                    @Override
                    public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                        Task<Uri> urlTask = taskSnapshot.getStorage().getDownloadUrl();
                        while (!urlTask.isSuccessful()) ;
                        Uri downloadUrl = urlTask.getResult();
                    }
                });
        System.out.println("RES : " + res);
        return res;
    }catch (NullPointerException e){
        return null;
    }
}

Hope it helps you!

edited Apr 13 '19 at 12:17

answered Apr 13 '19 at 12:07

Amr Jyniat

345
5
12

well thank you so much, but the problem is that the methods returns the variable res before finishing the upload process, so this method returns null. – Monƶer Al-Ħusaini Apr 13 '19 at 12:16
just try now, and tell me. – Amr Jyniat Apr 13 '19 at 12:18
Oh I see what you did there, Yes this supposed to work; Thank you so much – Monƶer Al-Ħusaini Apr 13 '19 at 12:25
logically It supposed to work fine, but didn't work, the app freezes then exit. – Monƶer Al-Ħusaini Apr 14 '19 at 06:26
Ok, put the error which appears here and makes some logs in your code – Amr Jyniat Apr 15 '19 at 06:20

Make upload method return String "the uploaded file url"

2 Answers2

Linked