Question

有时，我总是遇到应用崩溃的情况，但并不总是使用以下代码，这对我来说很奇怪。我已经尝试过在该主题上找到的所有内容，包括摆脱for循环（第130行），（应用程序崩溃表明第131行是问题）。comment comment = snapshot.getValue（Comment.class）;。真的不知道该如何解决。在Firebase中，我有一个父类“ Comments”和两个孩子“ comment”和“ publisher”。如果有人有任何见识，将不胜感激。


CommentsActivity

package com.e.events;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;

import com.bumptech.glide.Glide;
import com.e.events.Adapter.CommentAdapter;
import com.e.events.Model.Comment;
import com.e.events.Model.User;
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.ValueEventListener;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

public class CommentsActivity extends AppCompatActivity {

    private RecyclerView recyclerView;
    private CommentAdapter commentAdapter;
    private List<Comment> commentList;

    EditText addcomment;
    ImageView image_profile, checkmark_post_comment;

    String postid;
    String publisherid;

    FirebaseUser firebaseUser;

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

        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        getSupportActionBar().setTitle("Comments");
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        toolbar.setNavigationOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                finish();
            }
        });

        recyclerView = findViewById(R.id.recycler_view);
        recyclerView.setHasFixedSize(true);
        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this);
        recyclerView.setLayoutManager(linearLayoutManager);
        commentList = new ArrayList<>();
        commentAdapter = new CommentAdapter(this, commentList);
        recyclerView.setAdapter(commentAdapter);

        addcomment = findViewById(R.id.add_comment);
        image_profile = findViewById(R.id.image_profile);
        checkmark_post_comment = findViewById(R.id.checkmark_post_comment);

        firebaseUser = FirebaseAuth.getInstance().getCurrentUser();

        Intent intent = getIntent();
        postid = intent.getStringExtra("postid");
        publisherid = intent.getStringExtra("publisherid");

        checkmark_post_comment.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (addcomment.getText().toString().equals("")) {
                    Toast.makeText(CommentsActivity.this, "Cannot send empty comments", Toast.LENGTH_SHORT).show();
                } else {
                    addcomment();
                }
            }
        });

        getImage();
        readComments();
    }

    private void addcomment() {
        DatabaseReference reference = FirebaseDatabase.getInstance().getReference("Comments").child(postid);

        HashMap<String, Object> hashMap = new HashMap<>();
        hashMap.put("comment", addcomment.getText().toString());
        hashMap.put("publisher", firebaseUser.getUid());

        reference.push().setValue(hashMap);
        addcomment.setText("");
    }

    private void getImage() {
        DatabaseReference reference = FirebaseDatabase.getInstance().getReference("Users").child(firebaseUser.getUid());

        reference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                User user = dataSnapshot.getValue(User.class);
                Glide.with(getApplicationContext()).load(user.getImageurl()).into(image_profile);
            }

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

            }
        });
    }

    private void readComments() {
        DatabaseReference reference = FirebaseDatabase.getInstance().getReference("Comments").child(postid);

        reference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                commentList.clear();
                for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
                    Comment comment = snapshot.getValue(Comment.class);
                    commentList.add(comment);
                }

                commentAdapter.notifyDataSetChanged();
            }

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

            }
        });
    }
}

LOGCAT

进程：com.e.events，PID：741 com.google.firebase.database.DatabaseException：无法将java.lang.Boolean类型的对象转换为com.e.events.Model.Comment类型在com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertBean（com.google.firebase：firebase-database @@ 19.2.0：435） com.google.firebase.database.core.utilities.encoding.CustomClassMapper.deserializeToClass（com.google.firebase：firebase-database @@ 19.2.0：231） com.google.firebase.database.core.utilities.encoding.CustomClassMapper.convertToCustomClass（com.google.firebase：firebase-database @@ 19.2.0：79） com.google.firebase.database.DataSnapshot.getValue（com.google.firebase：firebase-database @@ 19.2.0：203）在com.e.events.CommentsActivity $ 4.onDataChange（CommentsActivity.java:131） com.google.firebase.database.core.ValueEventRegistration.fireEvent（com.google.firebase：firebase-database @@ 19.2.0：75） com.google.firebase.database.core.view.DataEvent.fire（com.google.firebase：firebase-database @@ 19.2.0：63） com.google.firebase.database.core.view.EventRaiser $ 1.run（com.google.firebase：firebase-database @@ 19.2.0：55）在android.os.Handler.handleCallback（Handler.java:907）在android.os.Handler.dispatchMessage（Handler.java:105）在android.os.Looper.loop（Looper.java:216）在android.app.ActivityThread.main（ActivityThread.java:7625）在java.lang.reflect.Method.invoke（本机方法）在com.android.internal.os.RuntimeInit $ MethodAndArgsCaller.run（RuntimeInit.java:524）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:987）


CommentAdapter

package com.e.events.Adapter;

import android.content.Context;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import com.bumptech.glide.Glide;
import com.e.events.MainActivity;
import com.e.events.Model.Comment;
import com.e.events.Model.User;
import com.e.events.R;
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.ValueEventListener;

import java.util.List;

public class CommentAdapter extends RecyclerView.Adapter<CommentAdapter.ViewHolder>{

    private Context mContext;
    private List<Comment> mComment;

    private FirebaseUser firebaseUser;

    public CommentAdapter(Context mContext, List<Comment> mComment) {
        this.mContext = mContext;
        this.mComment = mComment;
    }

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

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {

        firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
        final Comment comment = mComment.get(position);

        holder.comment.setText(comment.getComment());
        getUserInfo(holder.image_profile, holder.username, comment.getPublisher());

        holder.comment.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent intent = new Intent(mContext, MainActivity.class);
                intent.putExtra("publisherid", comment.getComment());
                mContext.startActivity(intent);
            }
        });

        holder.image_profile.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent intent = new Intent(mContext, MainActivity.class);
                intent.putExtra("publisherid", comment.getComment());
                mContext.startActivity(intent);
            }
        });

    }

    @Override
    public int getItemCount() {
        if (mComment != null) {
            return mComment.size();
        } else {
            return 0;
        }
    }

    public class ViewHolder extends RecyclerView.ViewHolder{

        public ImageView image_profile;
        public TextView username, comment;

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

            image_profile = itemView.findViewById(R.id.image_profile);
            comment = itemView.findViewById(R.id.comment);
            username = itemView.findViewById(R.id.username);
        }
    }

    private void getUserInfo(final ImageView imageView, final TextView username, String publisherid) {
        DatabaseReference reference = FirebaseDatabase.getInstance().getReference().child("Users").child(publisherid);

        reference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                User user = dataSnapshot.getValue(User.class);
                Glide.with(mContext).load(user.getImageurl()).into(imageView);
                username.setText(user.getUsername());
            }

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

            }
        });
    }
}

Model Comments

package com.e.events.Model;

public class Comment {

    private String comment;
    private String publisher;

    public Comment(String comment, String publisher) {
        this.comment = comment;
        this.publisher = publisher;
    }

    public Comment() {
    }

    public String getComment() {
        return comment;
    }

    public void setComment(String comment) {
        this.comment = comment;
    }

    public String getPublisher() {
        return publisher;
    }

    public void setPublisher(String publisher) {
        this.publisher = publisher;
    }
}

无法将java.lang.Boolean类型的对象转换为com

0 个答案: