java - Firebase DatabaseException 无法将 java.lang.Long 类型的值转换为 String

Question

当我尝试检索数据库中的数据并将其显示在上面时，我不断收到错误 com.google.firebase.database.DatabaseException: 无法将 java.lang.Long 类型的值转换为 String一个 TextView 。

Firebase数据库截图中的数据:

这是我的对象模型

public class AdminOrders {

    private String customeraddress, customername, customerphone, date, state, time, totalAmount;

    public AdminOrders() {

    }

    public AdminOrders(String customeraddress, String customername, String customerphone, String date, String state, String time, String totalAmount) {
        this.customeraddress = customeraddress;
        this.customername = customername;
        this.customerphone = customerphone;
        this.date = date;
        this.state = state;
        this.time = time;
        this.totalAmount = totalAmount;
    }

    public String getCustomeraddress() {
        return customeraddress;
    }

    public void setCustomeraddress(String customeraddress) {
        this.customeraddress = customeraddress;
    }

    public String getCustomername() {
        return customername;
    }

    public void setCustomername(String customername) {
        this.customername = customername;
    }

    public String getCustomerphone() {
        return customerphone;
    }

    public void setCustomerphone(String customerphone) {
        this.customerphone = customerphone;
    }

    public String getDate() {
        return date;
    }

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

    public String getState() {
        return state;
    }

    public void setState(String state) {
        this.state = state;
    }

    public String getTime() {
        return time;
    }

    public void setTime(String time) {
        this.time = time;
    }

    public String getTotalAmount() {
        return totalAmount;
    }

    public void setTotalAmount(String totalAmount) {
        this.totalAmount = totalAmount;
    }
}

这是我的代码。

public class AdminNewOrdersActivity extends AppCompatActivity {

    private RecyclerView orderList;
    private DatabaseReference ordersRef;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_admin_new_orders);

        ordersRef = FirebaseDatabase.getInstance().getReference().child("Orders");

        orderList = findViewById(R.id.recyclerView_vieworders);
        orderList.setLayoutManager(new LinearLayoutManager(this));


    }

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

        FirebaseRecyclerOptions<AdminOrders> options = new FirebaseRecyclerOptions.Builder<AdminOrders>()
                .setQuery(ordersRef, AdminOrders.class)
                .build();

        FirebaseRecyclerAdapter<AdminOrders, AdminOrdersViewHolder> adapter =
                new FirebaseRecyclerAdapter<AdminOrders, AdminOrdersViewHolder>(options) {
                    @Override
                    protected void onBindViewHolder(@NonNull AdminOrdersViewHolder holder, int position, @NonNull AdminOrders model) {
                        holder.username.setText(model.getCustomername());
                        holder.phonenum.setText(model.getCustomerphone());
                        holder.totalprice.setText(model.getTotalAmount());
                        holder.address.setText(model.getCustomeraddress());
                        holder.datetime.setText(model.getDate() + " " + model.getTime());
                    }

                    @NonNull
                    @Override
                    public AdminOrdersViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
                        View view =     LayoutInflater.from(parent.getContext()).inflate(R.layout.order_layout, parent, false);
                        return new AdminOrdersViewHolder(view);
                    }
                };
        orderList.setAdapter(adapter);
        adapter.startListening();
    }

    public static  class AdminOrdersViewHolder extends RecyclerView.ViewHolder {

        public TextView username, phonenum, totalprice, address, datetime;
        public Button showorderproducts;

        public AdminOrdersViewHolder(@NonNull View itemView) {
            super(itemView);

            username = itemView.findViewById(R.id.textView_username_adminorders);
            phonenum = itemView.findViewById(R.id.textView_phonenum);
            totalprice = itemView.findViewById(R.id.textView_price);
            address = itemView.findViewById(R.id.textView_address);
            datetime = itemView.findViewById(R.id.textView_datetime);
            showorderproducts = itemView.findViewById(R.id.button_showorderproducts);

        }
    }
}

完整的堆栈跟踪:

FATAL EXCEPTION: main
Process: com.dbethelfarm.bethelfarmgate, PID: 23665
com.google.firebase.database.DatabaseException: Failed to convert value of type java.lang.Long to String
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertString(com.google.firebase:firebase-database@@19.2.0:425)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToClass(com.google.firebase:firebase-database@@19.2.0:216)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToType(com.google.firebase:firebase-database@@19.2.0:178)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.access$100(com.google.firebase:firebase-database@@19.2.0:47)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper$BeanMapper.deserialize(com.google.firebase:firebase-database@@19.2.0:592)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper$BeanMapper.deserialize(com.google.firebase:firebase-database@@19.2.0:562)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertBean(com.google.firebase:firebase-database@@19.2.0:432)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToClass(com.google.firebase:firebase-database@@19.2.0:231)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertToCustomClass(com.google.firebase:firebase-database@@19.2.0:79)
    at com.google.firebase.database.DataSnapshot.getValue(com.google.firebase:firebase-database@@19.2.0:203)
    at com.firebase.ui.database.ClassSnapshotParser.parseSnapshot(ClassSnapshotParser.java:29)
    at com.firebase.ui.database.ClassSnapshotParser.parseSnapshot(ClassSnapshotParser.java:15)
    at com.firebase.ui.common.BaseCachingSnapshotParser.parseSnapshot(BaseCachingSnapshotParser.java:36)
    at com.firebase.ui.common.BaseObservableSnapshotArray.get(BaseObservableSnapshotArray.java:52)
    at com.firebase.ui.database.FirebaseRecyclerAdapter.getItem(FirebaseRecyclerAdapter.java:109)
    at com.firebase.ui.database.FirebaseRecyclerAdapter.onBindViewHolder(FirebaseRecyclerAdapter.java:149)
    at androidx.recyclerview.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6781)
    at androidx.recyclerview.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6823)
    at androidx.recyclerview.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5752)
    at androidx.recyclerview.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:6019)
    at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5858)
    at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5854)
    at androidx.recyclerview.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2230)
    at androidx.recyclerview.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1557)
    at androidx.recyclerview.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1517)
    at androidx.recyclerview.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:612)
    at androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3924)
    at androidx.recyclerview.widget.RecyclerView.dispatchLayout(RecyclerView.java:3641)
    at androidx.recyclerview.widget.RecyclerView.onLayout(RecyclerView.java:4194)
    at android.view.View.layout(View.java:15697)
    at android.view.ViewGroup.layout(ViewGroup.java:5064)
    at androidx.constraintlayout.widget.ConstraintLayout.onLayout(ConstraintLayout.java:1915)
    at android.view.View.layout(View.java:15697)
    at android.view.ViewGroup.layout(ViewGroup.java:5064)
    at android.widget.FrameLayout.layoutChildren(FrameLayout.java:579)
    at android.widget.FrameLayout.onLayout(FrameLayout.java:514)
    at android.view.View.layout(View.java:15697)
    at android.view.ViewGroup.layout(ViewGroup.java:5064)
    at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1703)
    at android.widget.LinearLayout.layoutVertical(LinearLayout

Answer 1

字符串totalAmount 导致了该问题。

在您的 FirebaseDB 中，它将值显示为 0，它是 long 值类型。但在您的 POJO 类中，它被声明为 String。因此异常(exception)。

解决方案:

只需将类型更改为 long 即可。对于totalAmount 的getter 和setter，您还必须将类型更改为long。

或者

将 FirebaseDB 中的 totalAmount 类型更改为 String。

我推荐第一种方法，因为它是一个可能在将来的某些计算中使用的数字。