java - 无法将类型java.lang.String的值转换为int？

我正在尝试在“文本”视图中显示总费用，但是应用程序一直在给我这个错误。该应用程序使用Firebase，由于只需要显示，所以我将getAmount（）和setAmount（）初始化为String。它可以作为字符串使用，但是金额不会增加到自己身上，而是像字符串一样位于第一个金额的前面。任何人都知道我该怎么做才能使我的簧片整数。

我正在使用getAmount（）类型，它以整数形式启动。

错误在addValueEvent侦听器内的个人片段中
救命！

addValueEventListener应该向我显示总额的个人片段。

import android.annotation.SuppressLint;
import android.content.pm.ActivityInfo;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.firebase.ui.database.FirebaseRecyclerOptions;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.Query;
import com.google.firebase.database.ValueEventListener;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.ItemTouchHelper;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

public class personalFragment extends Fragment {

    private FirebaseAuth mAuth;
    private String currentUserID;
    private RecyclerView recyclerView;
    private FirebaseRecyclerAdapter adapter;
    String [] listValue = {};
    private DatabaseReference mDatabase;
    private TextView expense_txt;

    @SuppressLint("SourceLockedOrientationActivity")
    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        final View myView = inflater.inflate(R.layout.fragment_personal, container, false);


        FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
        String uid = user.getUid();
        mDatabase    = FirebaseDatabase.getInstance().getReference("Expenses").child(uid);
        mAuth = FirebaseAuth.getInstance();
        currentUserID = mAuth.getCurrentUser().getUid();
        recyclerView = myView.findViewById(R.id.recycler_expense);
        expense_txt = myView.findViewById(R.id.expenses_txt);
        getActivity().setRequestedOrientation(
                ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);

        final LinearLayoutManager layoutManager = new LinearLayoutManager(getActivity());
        layoutManager.setStackFromEnd(true);
        layoutManager.setReverseLayout(true);
        recyclerView.setHasFixedSize(true);


        Query query = FirebaseDatabase.getInstance()
                .getReference("Expenses")
                .child(currentUserID)
                .limitToLast(100);

        FirebaseRecyclerOptions<PersonalExpenses> options =
                new FirebaseRecyclerOptions.Builder<PersonalExpenses>()
                        .setQuery(query, PersonalExpenses.class)
                        .build();


        adapter = new FirebaseRecyclerAdapter<PersonalExpenses, MyViewHolder>(options) {
            @Override
            protected void onBindViewHolder(final MyViewHolder holder, int position, PersonalExpenses personalExpenses) {


                holder.setDate(personalExpenses.getDate());
                holder.setDescription(personalExpenses.getDescription());
                holder.setAmount(personalExpenses.getAmount());
                holder.setType(personalExpenses.getType());
                //holder.setCurrency(personalExpenses.getCurrency());
            }

            @Override
            public MyViewHolder onCreateViewHolder( ViewGroup parent, int viewType) {
                View view = LayoutInflater.from(parent.getContext())
                        .inflate(R.layout.expense_recycler, parent, false);
                return new MyViewHolder(view);
            }
        };
        recyclerView.setLayoutManager(layoutManager);
        recyclerView.setAdapter(adapter);

        final ItemTouchHelper helper = new ItemTouchHelper(new ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.LEFT) {
            @Override
            public boolean onMove(@NonNull RecyclerView recyclerView, @NonNull RecyclerView.ViewHolder viewHolder, @NonNull RecyclerView.ViewHolder target) {
                return false;
            }

            @Override
            public void onSwiped(@NonNull RecyclerView.ViewHolder target, int i) {

               int swipedPosition = target.getAdapterPosition();
               adapter.notifyDataSetChanged();

            }
        });
        helper.attachToRecyclerView(recyclerView);

        mDatabase.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

                int totalsum = 0;
                for(DataSnapshot mySnapshot: dataSnapshot.getChildren()){

                    PersonalExpenses personal = mySnapshot.getValue(PersonalExpenses.class);// Error appears for this line of code
                    totalsum += personal.getAmount();

                    String stTotalsum = String.valueOf((totalsum));

                    expense_txt.setText(stTotalsum);
                }



            }

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

            }
        });


        return myView;
    }


    @Override
    public void onStart() {

        super.onStart();
        adapter.startListening();
    }


    @Override
    public void onStop() {

        super.onStop();
        adapter.stopListening();
    }


   public static class MyViewHolder extends RecyclerView.ViewHolder {

        private final View mView;

        public MyViewHolder(View itemView) {
            super(itemView);
            mView = itemView;
        }

        protected void setDate(String date) {
            TextView mDate = mView.findViewById(R.id.date_income);
            mDate.setText(date);
        }

        protected void setType(String type) {
            TextView mType = mView.findViewById(R.id.type_txt);
            mType.setText(type);
        }

        protected void setDescription(String description) {
            TextView mNote = mView.findViewById(R.id.note_txt);
            mNote.setText(description);
        }

        protected void setAmount(int amount) {
            TextView mAmount = mView.findViewById(R.id.ammount_income);
            String strammount = String.valueOf(amount);
            mAmount.setText(strammount);
        }
        /*
       protected void setCurrency(String currency) {
           TextView mCurrency = mView.findViewById(R.id.ammount_income);
           mCurrency.setText(currency);
       }*/
    }
}

个人费用数据

public class PersonalExpenses {

    public String description;
    public int amount;
    public String date;
    public String type;
    public String currency;

    public PersonalExpenses() {}


    public PersonalExpenses(String description, int amount, String date, String type, String currency) {
        this.amount = amount;
        this.date = date;
        this.type = type;
        this.currency = currency;
        this.description = description;
    }


    public String getDescription() {
        return description;
    }

    public void setDescription(String description) {
        this.description = description;
    }

    public int getAmount() { return amount; }

    public void setAmount(int amount) { this.amount = amount; }

    public String getDate() {
        return date;
    }

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

    public String getType() {return type;}

    public void setType(String type) { this.type = type; }

    public String getCurrency() { return currency; }

    public void setCurrency(String currency) { this.currency = currency; }

}

这个错误

 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(com.google.firebase:firebase-database@@19.2.1:363)
        at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToPrimitive(com.google.firebase:firebase-database@@19.2.1:289)
        at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToClass(com.google.firebase:firebase-database@@19.2.1:214)
        at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToType(com.google.firebase:firebase-database@@19.2.1:178)
        at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.access$100(com.google.firebase:firebase-database@@19.2.1:47)
        at com.google.firebase.database.core.utilities.encoding.CustomClassMapper$BeanMapper.deserialize(com.google.firebase:firebase-database@@19.2.1:592)
        at com.google.firebase.database.core.utilities.encoding.CustomClassMapper$BeanMapper.deserialize(com.google.firebase:firebase-database@@19.2.1:562)
        at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertBean(com.google.firebase:firebase-database@@19.2.1:432)
        at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToClass(com.google.firebase:firebase-database@@19.2.1:231)
        at com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertToCustomClass(com.google.firebase:firebase-database@@19.2.1:79)
        at com.google.firebase.database.DataSnapshot.getValue(com.google.firebase:firebase-database@@19.2.1:203)
        at uk.brighton.ama75.project.personalFragment$3.onDataChange(personalFragment.java:118)
        at com.google.firebase.database.core.ValueEventRegistration.fireEvent(com.google.firebase:firebase-database@@19.2.1:75)
        at com.google.firebase.database.core.view.DataEvent.fire(com.google.firebase:firebase-database@@19.2.1:63)
        at com.google.firebase.database.core.view.EventRaiser$1.run(com.google.firebase:firebase-database@@19.2.1:55)
        at android.os.Handler.handleCallback(Handler.java:790)
        at android.os.Handler.dispatchMessage(Handler.java:99)
        at android.os.Looper.loop(Looper.java:164)
        at android.app.ActivityThread.main(ActivityThread.java:6494)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

Here is the database from Firebase

这就是我将数据存储在数据库中的方式

expenses.setDescription(mDescription.getText().toString().trim());
                expenses.setAmount(Integer.valueOf(mAmount.getText().toString().trim()));
                expenses.setDate(mDate.getText().toString().trim());
                expenses.setType(text.trim());
                mDatabase.push().setValue(expenses);

最佳答案

我猜您的数据库正在以字符串格式发送getAmount。
用

int totalsum = 0;
for(DataSnapshot mySnapshot: dataSnapshot.getChildren()) {
PersonalExpenses personal = mySnapshot.getValue(PersonalExpenses.class);
totalsum += Integer.parseInt(personal.getAmount());
}
String stTotalsum = String.valueOf(totalsum);
expense_txt.setText(stTotalsum);