如何从Firestore中检索数组地图数据并存储在android studio中的数组中？

Question

完整数据库结构

错误

DocumentReference docRef = db.collection("user").document("65pH8UOnV4Pz8oxogsqsL9eE91L2");
            docRef.get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
                @Override
                public void onComplete(@NonNull Task<DocumentSnapshot> task) {
                    if (task.isSuccessful()) {
                        DocumentSnapshot document = task.getResult();
                        if (document.exists()) {
                             String[] array = (String[]) document.getData().get("card");
                                    Log.d(TAG, "DocumentSnapshot data: "+ document.getData().get("card"));
                        } else {
                            Log.d(TAG, "No such document");
                        }
                    } else {
                        Log.d(TAG, "get failed with ", task.getException());
                    }
                }
            });

Answer 1

为了解析结果，您可以将模型java类与firestore上的结构相同，然后使用它在您的onComplete方法中进行解析。

//UserResponse.java
    public class UserResponse {

    private ArrayList<Card> card;
    private String balance;
    private String email;
    private String name;
    private String phonenumber;

    public String getBalance() {
        return balance;
    }

    public void setBalance(String balance) {
        this.balance = balance;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPhonenumber() {
        return phonenumber;
    }

    public void setPhonenumber(String phonenumber) {
        this.phonenumber = phonenumber;
    }


    public  ArrayList<Card> getCards(){
        return card;
    }
    public void setCard(ArrayList<Card> card){
        this.card = card;
    }


}
//Card.java
public class Card{

    private String cvv;

    private String exp;

    public String getCvv() {
        return cvv;
    }

    public void setCvv(String cvv) {
        this.cvv = cvv;
    }

    public String getExp() {
        return exp;
    }

    public void setExp(String exp) {
        this.exp = exp;
    }

    public String getCarddetail() {
        return carddetail;
    }

    public void setCarddetail(String carddetail) {
        this.carddetail = carddetail;
    }

    private String carddetail;
   
}

然后在firestore中get code change添加以下行

UserResponse userResponse = document.toObject(UserResponse.class)
ArrayList<Card> cards = userResponse.getCards();

像这样：

DocumentReference docRef = db.collection("user").document("65pH8UOnV4Pz8oxogsqsL9eE91L2");
        docRef.get().addOnCompleteListener(new OnCompleteListener<DocumentSnapshot>() {
    @Override
    public void onComplete(@NonNull Task<DocumentSnapshot> task) {
        if (task.isSuccessful()) {
            DocumentSnapshot document = task.getResult();
            if (document.exists()) {
                UserResponse userResponse = document.toObject(UserResponse.class);
             ArrayList<Card> cards = userResponse.getCards();

                Log.d(TAG, "DocumentSnapshot data: "+ userResponse.getCards());
            } else {
                Log.d(TAG, "No such document");
            }
        } else {
            Log.d(TAG, "get failed with ", task.getException());
        }
    }
});