Display data from user uid with Firebase Database

Question

I want to recover data from the uid and then display them in RecyclerView.

I managed to recover the child/parent under Withdrawal thanks to the uid.

This is what it looks like in Java:

referenceWithdraw = FirebaseDatabase.getInstance().getReference().child("Withdraw");
Query queryUid = referenceWithdraw.orderByChild("uid").equalTo(user.getUid());
    queryUid.get().addOnCompleteListener(task -> {
        if (task.isSuccessful()) {
            for (DataSnapshot dataSnapshot : task.getResult().getChildren()) {
                String id = dataSnapshot.child("id").getValue(String.class)

                    }
                    @Override
                    public void onCancelled(@NonNull DatabaseError error) {

                    }
                });

            }
        } else {
            ///
        }
   });

String id = ... retrieves the child value.

So far everything is fine except when I add this under the String id = ... :

referenceWithdraw.child(id).addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(@NonNull DataSnapshot snapshot) {
        WithdrawProfile profile = snapshot.getValue(WithdrawProfile.class);
        list.add(profile);
        adapter.notifyDataSetChanged();
    }

I have this error appearing in my Logcat :

com.google.firebase.database.DatabaseException: Failed to convert a value of type java.lang.String to int
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertInteger(CustomClassMapper.java:364)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToPrimitive(CustomClassMapper.java:290)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToClass(CustomClassMapper.java:215)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToType(CustomClassMapper.java:179)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.access$100(CustomClassMapper.java:48)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper$BeanMapper.deserialize(CustomClassMapper.java:593)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper$BeanMapper.deserialize(CustomClassMapper.java:563)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertBean(CustomClassMapper.java:433)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToClass(CustomClassMapper.java:232)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertToCustomClass(CustomClassMapper.java:80)
    at com.google.firebase.database.DataSnapshot.getValue(DataSnapshot.java:203)
    at com.pckage.app.android.withdraw.Withdraw$1.onDataChange(Withdraw.java:62)
    at com.google.firebase.database.core.ValueEventRegistration.fireEvent(ValueEventRegistration.java:75)
    at com.google.firebase.database.core.view.DataEvent.fire(DataEvent.java:63)
    at com.google.firebase.database.core.view.EventRaiser$1.run(EventRaiser.java:55)
    at android.os.Handler.handleCallback(Handler.java:938)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:264)
    at android.app.ActivityThread.main(ActivityThread.java:8306)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:632)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1049)

And finally here is my WithdrawProfile :

public class WithdrawProfile {
    private String date, email, status, id;
    private int prize;
    public WithdrawProfile(){}

    public WithdrawProfile(String date, String email, String status, String id, int prize) {
        this.date = date;
        this.email = email;
        this.status = status;
        this.id = id;
        this.prize = prize;
    }

    public String getDate() {
        return date;
    }

    public void setDate(String date) {
        this.date = date;
    }

    public String getEmail() {
        return email;
    }

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

    public String getStatus() {
        return status;
    }

    public void setStatus(String status) {
        this.status = status;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public int getPrize() {
        return prize;
    }

    public void setPrize(int prize) {
        this.prize = prize;
    }
}

My database :

{
  "Daily" : {
    "KuTKHdv1qeYS1NeQVZlqYdZYyNi1" : {
      "date" : "07/01/2022"
    }
  },
  "Users" : {
    "KuTKHdv1qeYS1NeQVZlqYdZYyNi1" : {
      //Other value
      "uid" : "KuTKHdv1qeYS1NeQVZlqYdZYyNi1"
    }
  },
  "Withdraw" : {
    "-MszSsu9rn6XzRMUNgTc" : {
      "date" : "09/01/2022",
      "id" : "-MszSsu9rn6XzRMUNgTc",
      "email" : "test@gmail.com",
      "prize" : "1000",
      "statut" : "Pending",
      "uid" : "KuTKHdv1qeYS1NeQVZlqYdZYyNi1"
    }
  }
}

Thank you for your time

Answer 1

The problem is in reading this value from the database:

"prize" : "1000",

In your Java class you define prize as an int:

public int getPrize() {
    return prize;
}

public void setPrize(int prize) {
    this.prize = prize;
}

But in your database it is stored as a string value: "1000". Since they're not the same type, Firebase can't read the prize value and throws an error.

The solution is to either store the prize as a (whole) number:

"prize" : 1000,

Or to make it a string in your Java code too:

private String prize;

...

public String getPrize() {
    return prize;
}

public void setPrize(String prize) {
    this.prize = prize;
}