如何将数据放入 Firestore 数据库集合中的 Arraylist 中？

Question

我正在使用云 Firestore 数据库，我有一个名为 Jobpost1 的集合。 我想从这个集合中获取数据并存储在数组列表中。

我的Java代码

List<Jobpost> mList = new ArrayList<>();  //this is my arraylist
private CollectionReference collectionReference=db.collection("Job Post1");

 @Override
    public void onStart() {
        super.onStart();

        collectionReference.get()
                .addOnSuccessListener(new OnSuccessListener<QuerySnapshot>() {
                    @Override
                    public void onSuccess(QuerySnapshot queryDocumentSnapshots) {
                        if (!queryDocumentSnapshots.isEmpty()){
                            for (QueryDocumentSnapshot journals: queryDocumentSnapshots){

                            }

                        }else {

                            noJournalEntry.setVisibility(View.VISIBLE);

                        }
                    }
                })
                .addOnFailureListener(new OnFailureListener() {
                    @Override
                    public void onFailure(@NonNull Exception e) {

                    }
                });

    }

Answer 1

您可以通过这种方式填充列表

    List<Jobpost> mList = new ArrayList<>();  //this is my arraylist
    private CollectionReference collectionReference=db.collection("Job Post1");

    @Override
    public void onStart() {
        super.onStart();

        collectionReference.get()
                .addOnSuccessListener(new OnSuccessListener<QuerySnapshot>() {
                    @Override
                    public void onSuccess(QuerySnapshot queryDocumentSnapshots) {
                        if (!queryDocumentSnapshots.isEmpty()){
                            for (QueryDocumentSnapshot journals: queryDocumentSnapshots){
                                 JobPost jobPost= journals.toObject(JobPost.class);
                                 mList.add(jobPost);
                            }
                        }else {
                            noJournalEntry.setVisibility(View.VISIBLE);
                        }
                    }
                })
                .addOnFailureListener(new OnFailureListener() {
                    @Override
                    public void onFailure(@NonNull Exception e) {

                    }
                });

    }