'boolean java.lang.String.equals（java.lang.Object']上的NullPointer

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已经在这里查看了一段时间，无法找到答案。 Glide with函数正在第61行返回一个空指针，该行是text_events行，我不知道如何解决它……有什么想法吗？或者我该如何浓缩功能？应用程序正常运行，然后在滚动一些内容后10秒钟突然崩溃。谢谢！ 


CODE

package com.e.events.Adapter;

import android.content.Context;
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.Model.Post;
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 PostAdapter extends RecyclerView.Adapter<PostAdapter.ViewHolder>

    public Context mContext;
    public List<Post> mPost;

    private FirebaseUser firebaseUser;

    public PostAdapter(Context mContext, List<Post> mPost) 
        this.mContext = mContext;
        this.mPost = mPost;
    

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

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

        firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
        Post post = mPost.get(position);

        Glide.with(mContext).load(post.getPostimage()).into(holder.post_Image);

        if (post.getDescription().equals("")) 
            holder.description.setVisibility(View.GONE);
         else 
            holder.description.setVisibility(View.VISIBLE);
            holder.description.setText(post.getDescription());
        

        if (post.getText_event().equals("")) 
            holder.text_event.setVisibility(View.GONE);
         else 
            holder.text_event.setVisibility(View.VISIBLE);
            holder.text_event.setText(post.getText_event());
        

        if (post.getText_location().equals("")) 
            holder.text_location.setVisibility(View.GONE);
         else 
            holder.text_location.setVisibility(View.VISIBLE);
            holder.text_location.setText(post.getText_location());
        

        if (post.getText_date_time().equals("")) 
            holder.text_date_time.setVisibility(View.GONE);
         else 
            holder.text_date_time.setVisibility(View.VISIBLE);
            holder.text_date_time.setText(post.getText_date_time());
        
        publisherInfo(holder.image_profile, holder.username, post.getPublisher());

    

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

    

    public class ViewHolder extends RecyclerView.ViewHolder

        public ImageView image_profile, post_Image, like, comment;
        public TextView username, number_of_likes, description, number_of_comments, text_event, text_location, text_date_time;

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

            image_profile = itemView.findViewById(R.id.image_profile);
            post_Image = itemView.findViewById(R.id.post_image);
            like = itemView.findViewById(R.id.like);
            comment = itemView.findViewById(R.id.comment);
            username = itemView.findViewById(R.id.username);
            number_of_likes = itemView.findViewById(R.id.number_of_likes);
            description = itemView.findViewById(R.id.description);
            number_of_comments = itemView.findViewById(R.id.number_of_comments);
            text_event = itemView.findViewById(R.id.text_event);
            text_location = itemView.findViewById(R.id.text_location);
            text_date_time = itemView.findViewById(R.id.text_date_time);
        
    

    private void publisherInfo(final ImageView image_profile, final TextView username, String userid) 
        DatabaseReference reference = FirebaseDatabase.getInstance().getReference("Users").child(userid);

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

            

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) 

            
        );

E / AndroidRuntime：致命异常：主要流程：com.e.events，PID：25853java.lang.NullPointerException：尝试在空对象引用上调用虚拟方法'boolean java.lang.String.equals（java.lang.Object）'在com.e.events.Adapter.PostAdapter.onBindViewHolder（PostAdapter.java:63）在com.e.events.Adapter.PostAdapter.onBindViewHolder（PostAdapter.java:27）在androidx.recyclerview.widget.RecyclerView $ Adapter.onBindViewHolder（RecyclerView.java:6781）在androidx.recyclerview.widget.RecyclerView $ Adapter.bindViewHolder（RecyclerView.java:6823）在androidx.recyclerview.widget.RecyclerView $ Recycler.tryBindViewHolderByDeadline（RecyclerView.java:5752）在androidx.recyclerview.widget.RecyclerView $ Recycler.tryGetViewHolderForPositionByDeadline（RecyclerView.java:6019）在androidx.recyclerview.widget.RecyclerView $ Recycler.getViewForPosition（RecyclerView.java:5858）在androidx.recyclerview.widget.RecyclerView $ Recycler.getViewForPosition（RecyclerView.java:5854）在androidx.recyclerview.widget.LinearLayoutManager $ LayoutState.next（LinearLayoutManager.java:2230）在androidx.recyclerview.widget.LinearLayoutManager.layoutChunk（LinearLayoutManager.java:1557）在androidx.recyclerview.widget.LinearLayoutManager.fill（LinearLayoutManager.java:1517）在androidx.recyclerview.widget.LinearLayoutManager.onLayoutChildren（LinearLayoutManager.java:612）在androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep2（RecyclerView.java:3924）在androidx.recyclerview.widget.RecyclerView.onMeasure（RecyclerView.java:3336）在android.view.View.measure（View.java:24530）在android.widget.RelativeLayout.measureChildHorizo​​ntal（RelativeLayout.java:735）在android.widget.RelativeLayout.onMeasure（RelativeLayout.java:481）在android.view.View.measure（View.java:24530）在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:6828）在android.widget.FrameLayout.onMeasure（FrameLayout.java:194）在android.view.View.measure（View.java:24530）在android.widget.RelativeLayout.measureChildHorizo​​ntal（RelativeLayout.java:735）在android.widget.RelativeLayout.onMeasure（RelativeLayout.java:481）在android.view.View.measure（View.java:24530）在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:6828）在android.widget.FrameLayout.onMeasure（FrameLayout.java:194）在androidx.appcompat.widget.ContentFrameLayout.onMeasure（ContentFrameLayout.java:143）在android.view.View.measure（View.java:24530）在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:6828）在android.widget.LinearLayout.measureChildBeforeLayout（LinearLayout.java:1552）在android.widget.LinearLayout.measureVertical（LinearLayout.java:842）在android.widget.LinearLayout.onMeasure（LinearLayout.java:721）在android.view.View.measure（View.java:24530）在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:6828）在android.widget.FrameLayout.onMeasure（FrameLayout.java:194）在android.view.View.measure（View.java:24530）在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:6828）在android.widget.LinearLayout.measureChildBeforeLayout（LinearLayout.java:1552）在android.widget.LinearLayout.measureVertical（LinearLayout.java:842）在android.widget.LinearLayout.onMeasure（LinearLayout.java:721）在android.view.View.measure（View.java:24530）在android.view.ViewGroup.measureChildWithMargins（ViewGroup.java:6828）在android.widget.FrameLayout.onMeasure（FrameLayout.java:194）在com.android.internal.policy.DecorView.onMeasure（DecorView.java:742）在android.view.View.measure（View.java:24530）在android.view.ViewRootImpl.performMeasure（ViewRootImpl.java:3006）在android.view.ViewRootImpl.measureHierarchy（ViewRootImpl.java:1833）在android.view.ViewRootImpl.performTraversals（ViewRootImpl.java:2122）在android.view.ViewRootImpl.doTraversal（ViewRootImpl.java:1721）在android.view.ViewRootImpl $ TraversalRunnable.run（ViewRootImpl.java:7598）在android.view.Choreographer $ CallbackRecord.run（Choreographer.java:966）在android.view.Choreographer.doCallbacks（Choreographer.java:790）在android.view.Choreographer.doFrame（Choreographer.java:725）在android.view.Choreographer $ FrameDisplayEventReceiver.run（Choreographer.java:951）在android.os.Handler.handleCallback（Handler.java:883）在android.os.Handler.dispatchMessage（Handler.java:100）在android.os.Looper.loop（Looper.java:214）在android.app.ActivityThread.main（ActivityThread.java:7356）在java.lang.reflect.Method.invoke（本机方法）在com.android.internal.os.RuntimeInit $ MethodAndArgsCaller.run（RuntimeInit.java:492）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:930）

答案

方法post.getText_event()返回null，然后尝试在其上调用equals("")。结果，您得到NullPointerExceptio n。为了避免出现NullPointerException，您应该像这样更改代码

"".equals(post.getText_event())

。

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