DataBaseException: Can't convert object of type java.lang.String to type com.example.testingeve-CodePudding

I've searched everything for this error and this is my first time asking a question. And I'm trying to do a Nested RecyclerView for my Shipments Page on my app I don't know what's to my problem with my code. I tried everything and it keeps saying that's the error. I don't know what to do

Here is the error at the Logcat

2022-08-29 23:31:23.029 16114-16114/com.example.testingeverything E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.testingeverything, PID: 16114
com.google.firebase.database.DatabaseException: Can't convert object of type java.lang.String to type com.example.testingeverything.ShippingDetail
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertBean(CustomClassMapper.java:436)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToClass(CustomClassMapper.java:232)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToType(CustomClassMapper.java:179)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToParameterizedType(CustomClassMapper.java:265)
    at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToType(CustomClassMapper.java:177)
    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.example.testingeverything.ShipmentsActivity$1.onDataChange(ShipmentsActivity.java:42)
    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$1.run(EventRaiser.java:55)
    at android.os.Handler.handleCallback(Handler.java:790)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:164)
    at android.app.ActivityThread.main(ActivityThread.java:6494)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

ShipmentsActivity.java

public class ShipmentsActivity extends AppCompatActivity {
String userName = MainActivity.userName;
RecyclerView shipmentsRecyclerView;
ShipmentsActivityAdapter shipmentsActivityAdapter;
ArrayList<Shipments> shipments_list;
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference databaseReference = rootRef.child("Users").child(userName).child(userName   "Shipments");

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

    shipmentsRecyclerView = findViewById(R.id.shipments_recycler_view);
    shipmentsRecyclerView.setHasFixedSize(true);
    shipments_list = new ArrayList<>();

    shipmentsActivityAdapter = new ShipmentsActivityAdapter(this);
    shipmentsActivityAdapter.setShipments(shipments_list);
    shipmentsRecyclerView.setAdapter(shipmentsActivityAdapter);
    databaseReference.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot snapshot) {
            for (DataSnapshot snapshot1 : snapshot.getChildren()) {
                //This is where the error is
                Shipments shipments = snapshot1.getValue(Shipments.class);
                shipments_list.add(shipments);
            }
            shipmentsActivityAdapter.notifyDataSetChanged();
        }

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

        }
    });
}

Shipments.java

public class Shipments {

private Map<String, ShippingDetail> details;
private Map<String, ShippingProduct> products;

public Shipments(Map<String, ShippingDetail> details, Map<String, ShippingProduct> products) {
    this.details = details;
    this.products = products;
}

public Shipments() {
}

public Map<String, ShippingDetail> getDetails() {
    return details;
}

public void setDetails(Map<String, ShippingDetail> details) {
    this.details = details;
}

public Map<String, ShippingProduct> getProducts() {
    return products;
}

public void setProducts(Map<String, ShippingProduct> products) {
    this.products = products;
}

}

ShippingDetail.java

public class ShippingDetail {
private String emailaddress;
private String facebook;
private String fulladdress;
private String fullname;
private String paymentmethod;
private String phonenumber;
private String postalcode;
private String schedule;
private String region;
private boolean setenablebutton;
private String status;
private int totalprice;
private String tracknumber;

public ShippingDetail(String emailaddress, String facebook, String fulladdress, String fullname, String paymentmethod, String phonenumber, String postalcode, String schedule, String region, boolean setenablebutton, String status, int totalprice, String tracknumber) {
    this.emailaddress = emailaddress;
    this.facebook = facebook;
    this.fulladdress = fulladdress;
    this.fullname = fullname;
    this.paymentmethod = paymentmethod;
    this.phonenumber = phonenumber;
    this.postalcode = postalcode;
    this.schedule = schedule;
    this.region = region;
    this.setenablebutton = setenablebutton;
    this.status = status;
    this.totalprice = totalprice;
    this.tracknumber = tracknumber;
}

public ShippingDetail(){} //Below are getters and setters

ShipmentsActivityAdapter.java

public class ShipmentsActivityAdapter extends RecyclerView.Adapter<ShipmentsActivityAdapter.ViewHolder> {
private String userName = MainActivity.userName;
private List<Shipments> shipments = new ArrayList<>();
private Context context;

public ShipmentsActivityAdapter (Context context){this.context = context;}
public void setShipments (List<Shipments> shipments){
    this.shipments = shipments;
    notifyDataSetChanged();
}

public class ViewHolder extends  RecyclerView.ViewHolder{
    private RecyclerView productsRecyclerView;
    private RecyclerView detailsRecyclerView;
    private Button cancelButton;
    private List<ShippingProduct> shippingProducts_list;
    private List<ShippingDetail> shipmentsDetail_list;

    private DatabaseReference databaseForDetailsReference = FirebaseDatabase.getInstance().getReference().child("Users").child(userName).child(userName "Shipments");
    private DatabaseReference databaseForProductsReference = FirebaseDatabase.getInstance().getReference().child("Users").child(userName).child(userName "Shipments");
    public ViewHolder(@NonNull View itemView) {
        super(itemView);
        productsRecyclerView = itemView.findViewById(R.id.products_recyclerView);
        detailsRecyclerView = itemView.findViewById(R.id.details_recyclerView);
        cancelButton = itemView.findViewById(R.id.cancel_btn);
    }
}

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

@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
    ShippingDetailAdapter detailAdapter = new ShippingDetailAdapter(context);
    ShippingProductAdapter productAdapter = new ShippingProductAdapter(context);
    holder.shippingProducts_list = new ArrayList<>();
    holder.shipmentsDetail_list = new ArrayList<>();
    holder.detailsRecyclerView.setHasFixedSize(true);
    holder.productsRecyclerView.setHasFixedSize(true);
    holder.detailsRecyclerView.setLayoutManager(new LinearLayoutManager(context));
    holder.productsRecyclerView.setLayoutManager(new LinearLayoutManager(context));
    holder.detailsRecyclerView.setAdapter(detailAdapter);
    holder.productsRecyclerView.setAdapter(productAdapter);

    holder.databaseForDetailsReference.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot snapshot) {
            for (DataSnapshot snapshot1 : snapshot.getChildren()){
                String getTheKey = snapshot1.getKey();
                ShippingDetail shippingDetail = snapshot1.child(getTheKey).getValue(ShippingDetail.class);
                holder.shipmentsDetail_list.add(shippingDetail);
            }
        }

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

    holder.databaseForProductsReference.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot snapshot) {
            for (DataSnapshot snapshot1 : snapshot.getChildren()){
                String getTheKey = snapshot1.getKey();
                ShippingProduct shippingProduct = snapshot1.child(getTheKey).getValue(ShippingProduct.class);
                holder.shippingProducts_list.add(shippingProduct);
            }
        }

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

}

@Override
public int getItemCount() {
    return shipments.size();
}

}

This is the Database Structure

CodePudding user response：

When you attach a listener to the following reference:

rootRef.child("Users").child(userName).child(userName "Shipments");

And you're looping through the results, you aren't getting ShippingDetail objects, you're getting just a string called details, and hence the error. Why? Because under johnnyShipments node, there is a single direct child called details.

To solve this, you have to remove the extra details level, which in my opinion is not required, and this error will go away.