我都写好了注释 希望大家能尽力看懂 能帮我解决问题我非常感谢！！！

Adapter没有问题

下面是Activity

package com.RecyclerViewlayout.View;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.GridLayoutManager;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;

import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.HandlerThread;
import android.view.View;
import android.widget.Button;

import com.RecyclerViewlayout.adapter.ListViewAdapter;
import com.connect.bean.querybeanforAndroid;
import com.connect.dao.DeleteActivity;
import com.connect.dao.NewInsertActivity;
import com.connect.dao.UpdateActivity;
import com.google.gson.Gson;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonParser;
import com.test.hellowrold.R;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
public class ListViewActivity extends AppCompatActivity {
    RecyclerView recyclerView =null ;//RecyclerView 的全局变量
    List<querybeanforAndroid> beans = new ArrayList<querybeanforAndroid>();//将json字符串解析到List里面的全局变量list
    String querysqldata_forjson = null;//得到json字符串的全局变量
    Button buttondelete ; //删除按钮
    Button buttonupdate ; //修改按钮
    Button buttonInsert ; //新增按钮
    //RecyclerView adapter; //适配器的全局变量
    ListViewAdapter adapter;
    SwipeRefreshLayout swipeRefreshLayout;// 下拉刷新的SwipeRefreshLayout的全局变量
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        getjsonDate();//得到json字符串 并且赋值给 querysqldata_forjson

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_list_view);//加载默认布局文件

        recyclerView = this.findViewById(R.id.resyc_list);//给RecyclerView 控键键值（赋值声明）

        swipeRefreshLayout = this.findViewById(R.id.listView_refresh);//设置下拉刷新


        //下面 七行 是将json字符串解析到list里面
        Gson gson = new Gson();//创建Gson对象
        JsonParser jsonParser = new JsonParser();
        JsonArray jsonElements = jsonParser.parse(querysqldata_forjson).getAsJsonArray();//获取JsonArray对象
        for (JsonElement bean : jsonElements) {
            querybeanforAndroid bean1 = gson.fromJson(bean, querybeanforAndroid.class);//解析
            beans.add(bean1);
        }
        //设置查询界面的三个按钮 增删改的单击事件
        buttonInsert=findViewById(R.id.button_recyclerview_insert);
        buttonInsert.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(ListViewActivity.this, NewInsertActivity.class);
                startActivity(intent);
            }
        });
        buttonupdate=findViewById(R.id.recyclerview_update_button);
        buttondelete=findViewById(R.id.recyclerview_delete_button);
        buttondelete.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(ListViewActivity.this, DeleteActivity.class);
                startActivity(intent);
            }
        });
        buttonupdate.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(ListViewActivity.this, UpdateActivity.class);
                startActivity(intent);
            }
        });
        handlerDownPullrefresh();//下拉刷新的方法
        //加载LinearLayoutManager布局器
        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(ListViewActivity.this);
        //添加配置器
        recyclerView.setLayoutManager(linearLayoutManager);
        //创建适配器
        adapter = new ListViewAdapter(beans);
        //将适配器 添加设置 到RecyclerView里头
        recyclerView.setAdapter(adapter);

    }
    //下拉刷新方法
    private void handlerDownPullrefresh() {
        swipeRefreshLayout.setEnabled(true);//将下拉刷新设置开启 设置为true
        swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
            @Override
            public void onRefresh() {
                new Thread(new Runnable() {//下拉刷新也需要在新线程里面得到值
                    @Override
                    public void run() {
                        getjsonDate();
                        Gson gson = new Gson();//创建Gson对象
                        JsonParser jsonParser = new JsonParser();
                        JsonArray jsonElements = jsonParser.parse(querysqldata_forjson).getAsJsonArray();//获取JsonArray对象
                        for (JsonElement bean : jsonElements) {
                            querybeanforAndroid bean1 = gson.fromJson(bean, querybeanforAndroid.class);//解析
                            beans.add(bean1);
                        }
                        new Handler().postDelayed(new Runnable() {
                            @Override
                            public void run() {
                                //做两件事情
                                adapter.notifyDataSetChanged();//通知适配器更新UI数据
                                swipeRefreshLayout.setRefreshing(false);
                            }
                        },2000);//刷新2秒 毫秒为单位
                    }
                }).start();
            }
        });
    }
    //与java后台连接并且得到后台传来的字符串并且给querysqldata_forjson字符串赋值 querysqldata_forjson字符串是一个公共变量
    //并且连接java后台的servlet需要在新的线程里面连接 不然就会报异常
    public void getjsonDate() {
        new Thread(new Runnable() {
            @Override
            public void run() {
                String URLHttp = "http://192.168.43.150:8080/web2/queryservlet";//java后台servlet的字符串路径
                try {
                    URL url = new URL(URLHttp);//将字符串路径解析到URL里面去
                    HttpURLConnection connection = (HttpURLConnection) url.openConnection();//打开与后台的连接
                    connection.setRequestMethod("POST");//设置连接后台的方式
                    connection.setDoInput(true);  //允许输入流
                    connection.setDoOutput(true); //允许输出流
                    connection.setUseCaches(false);  //不允许使用缓存
                    connection.setRequestProperty("ser-Agent", "Fiddler");
                    connection.setRequestProperty("Content-Type", "application/json");
                    InputStream inputStream = connection.getInputStream();//从后台得到json对象结果
                    BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));//解析json格式的字符串
                    querysqldata_forjson = reader.readLine();//解析后赋值给querysqldata_frojson字符串
                } catch (MalformedURLException e) {
                    e.printStackTrace();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }).start();
    }
}

下面是Adapte

package com.RecyclerViewlayout.adapter;
import android.content.Intent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import com.RecyclerViewlayout.View.ListViewActivity;
import com.connect.bean.querybeanforAndroid;
import com.connect.dao.DeleteActivity;
import com.test.hellowrold.R;
import java.util.List;
public class ListViewAdapter extends RecyclerView.Adapter<ListViewAdapter.InnerHolder> {


    private List<querybeanforAndroid> data;
    public ListViewAdapter(List<querybeanforAndroid> data){
        this.data = data;

    }
    //这个方法用于创建条目的view ↓
    public InnerHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        //传进去的这个view其实就是条目的界面
        View view = View.inflate(parent.getContext(), R.layout.list_item_view,null);
        return new InnerHolder(view);
    }
    //这个方法是用来绑定holder的，一般用来设置数据
    @Override
    public void onBindViewHolder(@NonNull InnerHolder holder, int position) {
        //在这里设置数据

        holder.setData(holder,data.get(position));
    }
    @Override
    public int getItemCount() {//返回条目个数
        if(data!=null){
            return data.size();
        }
        else
            return 0;
    }
    public class InnerHolder extends RecyclerView.ViewHolder{
        TextView idtext;
        TextView nametext;
        TextView pricetext;
        Button deleteButton;
        Button updateButton;
        public InnerHolder(@NonNull View itemView) {
            super(itemView);
            //找到条目的控键
            idtext = itemView.findViewById(R.id.text_id_recyclerview);
            nametext = itemView.findViewById(R.id.text_name_recyclerview);
            pricetext = itemView.findViewById(R.id.text_price_recyclerview);
            deleteButton = itemView.findViewById(R.id.recyclerview_delete_button);
            updateButton = itemView.findViewById(R.id.recyclerview_update_button);
        }
            //这个方法用于设置数据
        public void setData(InnerHolder holder, querybeanforAndroid querybean) {

            holder.idtext.setText(String.valueOf(querybean.getId()));
            holder.nametext.setText(querybean.getName());
            holder.pricetext.setText(String.valueOf(querybean.getPrice()));
           /* holder.deleteButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    mOnItemClickListener.onItemClick();
                }
            });*/
            //以后完善了在修改按钮的单击删除和修改

        }
    }
}

下面是Layout布局

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >
    <TextView
        android:id="@+id/recyclerview_title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="查询界面"
        android:textSize="30sp"
        android:gravity="center_horizontal">

    </TextView>
    <Button
        android:id="@+id/button_recyclerview_insert"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/recyclerview_title"
        android:text="新增数据"
        android:textSize="20sp"
        android:layout_marginLeft="20dp"
        >

    </Button>
    <Button
        android:id="@+id/recyclerview_delete_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_toRightOf="@id/button_recyclerview_insert"
        android:layout_below="@id/recyclerview_title"
        android:text="删除数据"
        android:textSize="20sp"
        android:layout_marginLeft="20dp"
        >

    </Button>
    <Button
        android:id="@+id/recyclerview_update_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="修改数据"
        android:layout_toRightOf="@id/recyclerview_delete_button"
        android:layout_below="@id/recyclerview_title"
        android:textSize="20sp"
        android:layout_marginLeft="20dp"
        >

    </Button>

    <androidx.swiperefreshlayout.widget.SwipeRefreshLayout
        android:layout_below="@id/button_recyclerview_insert"
        android:id="@+id/listView_refresh"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">
        <androidx.recyclerview.widget.RecyclerView

            android:id="@+id/resyc_list"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            />
    </androidx.swiperefreshlayout.widget.SwipeRefreshLayout>

</RelativeLayout>