com.google.firebase.database.DatabaseException: Failed to convert a value of type java.lang.String to long

Sathishkumar G :

I am getting an error when following the docs of firebase database in attempting to retrieve data to an object for use.

Here is my object model

public class Cart {

    private String pid, pname, price, discount, quantity;

    public Cart() {
    }

    public Cart(String pid, String pname, String price, String discount, String quantity) {
        this.pid = pid;
        this.pname = pname;
        this.price = price;
        this.discount = discount;
        this.quantity = quantity;
    }

    public String getPid() {
        return pid;
    }

    public void setPid(String pid) {
        this.pid = pid;
    }

    public String getPname() {
        return pname;
    }

    public void setPname(String pname) {
        this.pname = pname;
    }

    public String getPrice() {
        return price;
    }

    public void setPrice(String price) {
        this.price = price;
    }

    public String getDiscount() {
        return discount;
    }

    public void setDiscount(String discount) {
        this.discount = discount;
    }

    public String getQuantity() {
        return quantity;
    }

    public void setQuantity(String quantity) {
        this.quantity = quantity;
    }
}

And finally, the code & line I get the error on is commented.

FirebaseRecyclerOptions<Cart> options =
    new FirebaseRecyclerOptions.Builder<Cart>()
    .setQuery(cartListRef.child("User View")
    .child(Prevalent.currentOnlineUser.getPhn_num())
    .child("Products"), Cart.class)
    .build();

FirebaseRecyclerAdapter<Cart, CartViewHolder> adapter =
    new FirebaseRecyclerAdapter<Cart, CartViewHolder>(options) {
        @Override
        protected void onBindViewHolder(@NonNull CartViewHolder holder, int position, @NonNull Cart model)
        {
            holder.jProductName.setText(model.getPname());
            holder.jProductPrice.setText("Price = Rs. " +model.getPrice());
            holder.jProductQuantity.setText("Quantity = " +model.getQuantity());

        }

        @NonNull
        @Override
        public CartViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int i)
        {
            View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.cart_items_layout, parent,false);
            CartViewHolder holder = new CartViewHolder(view);
            return holder;
        }
    };

recyclerView.setAdapter(adapter);
adapter.startListening();

Here is my database structure in Firebase.

And the full Stacktrace from logcat is here.

E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.dueaoinfo.shoppingapp, PID: 10511
com.google.firebase.database.DatabaseException: Failed to convert a value of type java.lang.String to long
    at com.google.android.gms.internal.firebase_database.zzkt.zzb(Unknown Source:616)
    at com.google.android.gms.internal.firebase_database.zzkt.zza(Unknown Source:301)
    at com.google.android.gms.internal.firebase_database.zzkt.zzb(Unknown Source:0)
    at com.google.android.gms.internal.firebase_database.zzku.zza(Unknown Source:71)
    at com.google.android.gms.internal.firebase_database.zzkt.zzb(Unknown Source:146)
    at com.google.android.gms.internal.firebase_database.zzkt.zza(Unknown Source:0)
    at com.google.firebase.database.DataSnapshot.getValue(Unknown Source:10)
    at com.firebase.ui.database.ClassSnapshotParser.parseSnapshot(ClassSnapshotParser.java:29)
    at com.firebase.ui.database.ClassSnapshotParser.parseSnapshot(ClassSnapshotParser.java:15)
    at com.firebase.ui.common.BaseCachingSnapshotParser.parseSnapshot(BaseCachingSnapshotParser.java:35)
    at com.firebase.ui.common.BaseObservableSnapshotArray.get(BaseObservableSnapshotArray.java:52)
    at com.firebase.ui.database.FirebaseRecyclerAdapter.getItem(FirebaseRecyclerAdapter.java:106)
    at com.firebase.ui.database.FirebaseRecyclerAdapter.onBindViewHolder(FirebaseRecyclerAdapter.java:122)
    at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6781)
    at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6823)
    at android.support.v7.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5752)
    at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:6019)
    at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5858)
    at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5854)
    at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2230)
    at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1557)
    at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1517)
    at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:612)
    at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3924)
    at android.support.v7.widget.RecyclerView.dispatchLayout(RecyclerView.java:3641)
    at android.support.v7.widget.RecyclerView.consumePendingUpdateOperations(RecyclerView.java:1888)
    at android.support.v7.widget.RecyclerView$1.run(RecyclerView.java:407)
    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:1092)
    at android.view.Choreographer.doCallbacks(Choreographer.java:888)
    at android.view.Choreographer.doFrame(Choreographer.java:816)
    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:1078)
    at android.os.Handler.handleCallback(Handler.java:873)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:201)
    at android.app.ActivityThread.main(ActivityThread.java:6823)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:547)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:873)

Reaz Murshed :

The quantity and discount are the Long values in your firebase database where in your Cart class it is declared as String. This is throwing the error. Declare the Cart class like the following.

public class Cart {

    private String pid, pname, price;
    private Long discount, quantity;

    public Cart() {
    }

    public Cart(String pid, String pname, String price, Long discount, Long quantity) {
        this.pid = pid;
        this.pname = pname;
        this.price = price;
        this.discount = discount;
        this.quantity = quantity;
    }

    public String getPid() {
        return pid;
    }

    public void setPid(String pid) {
        this.pid = pid;
    }

    public String getPname() {
        return pname;
    }

    public void setPname(String pname) {
        this.pname = pname;
    }

    public String getPrice() {
        return price;
    }

    public void setPrice(String price) {
        this.price = price;
    }

    public Long getDiscount() {
        return discount;
    }

    public void setDiscount(Long discount) {
        this.discount = discount;
    }

    public Long getQuantity() {
        return quantity;
    }

    public void setQuantity(Long quantity) {
        this.quantity = quantity;
    }
}

Hope that solves your problem.