逻辑代码：

package com.example.fightvirus;


import android.graphics.Color;
import android.os.Bundle;

import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;

import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.TextView;
import android.widget.Toast;

import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;
import com.github.mikephil.charting.charts.BarChart;
import com.github.mikephil.charting.components.Description;
import com.github.mikephil.charting.components.XAxis;
import com.github.mikephil.charting.components.YAxis;
import com.github.mikephil.charting.data.BarData;
import com.github.mikephil.charting.data.BarDataSet;
import com.github.mikephil.charting.data.BarEntry;
import com.github.mikephil.charting.formatter.IndexAxisValueFormatter;
import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;

import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.List;


/**
 * A simple {@link Fragment} subclass.
 */
public class HomeChatFragment extends Fragment {
    BarChart barChart;
    private List<CityData> cityList = new ArrayList<CityData>();
    private RadioGroup radioGroup;
    private RadioButton province,city,country;
    private EditText queryDate,keyName;
    private Button queryButton;
    private String way,key,date;

    public HomeChatFragment() {
        // Required empty public constructor

    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View inflate = inflater.inflate(R.layout.fragment_home_chat, container, false);
        barChart = inflate.findViewById(R.id.barChart);
        radioGroup = inflate.findViewById(R.id.radioGroup);
        province = inflate.findViewById(R.id.province);
        city = inflate.findViewById(R.id.city);
        country = inflate.findViewById(R.id.country);
        queryDate = inflate.findViewById(R.id.queryDate);
        keyName = inflate.findViewById(R.id.keyName);
        queryButton = inflate.findViewById(R.id.queryButton);
        return inflate;
    }

    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(RadioGroup group, int checkedId) {
                switch (checkedId){
                    case R.id.province:
                        way = "getInfoByProvince";
                        break;
                    case R.id.country:
                        way = "getInfoByCountry";
                        break;
                    case R.id.city:
                        way = "getInfoByName";
                        break;
                    default:
                        break;
                }
            }
        });

        queryButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                key = String.valueOf(keyName.getText().toString().trim());
                date = String.valueOf(queryDate.getText().toString());
                String url = "http://117.50.96.227/EpidemicInfo/city/" + way + "/" + key + "/" + date;
                RequestQueue queue = Volley.newRequestQueue(getActivity());
//                Toast.makeText(getActivity(),url,Toast.LENGTH_SHORT).show();
                StringRequest stringRequest = new StringRequest(StringRequest.Method.GET,
                        url,
                        new Response.Listener<String>() {
                            @Override
                            public void onResponse(String response) {
                                Gson gson = new Gson();
                                Type cityType = new TypeToken<ArrayList<CityData>>() {
                                }.getType();
                                cityList = gson.fromJson(response, cityType);
                                barChart.clear();
                                initMyView(cityList);
                            }
                        },
                        new Response.ErrorListener() {
                            @Override
                            public void onErrorResponse(VolleyError error) {
                                Log.e("myTAG", "onErrorResponse: " + error);
                            }
                        });
                queue.add(stringRequest);
            }
        });


    }

    private void initMyView(List<CityData> cityList) {
        //chart的设计
        Description description = new Description();
        description.setText("该页面数据仅供参考");
        barChart.setNoDataText("没有数据!");
        barChart.setDescription(description);
        barChart.setDrawBorders(false);
        barChart.setBackgroundColor(Color.WHITE);
        barChart.setDrawGridBackground(false);
        barChart.setDrawBarShadow(false);
        barChart.setHighlightFullBarEnabled(false);
        barChart.setDragEnabled(true);
        barChart.setNoDataText("正在加载数据...");


        //X轴数据
        ArrayList<BarEntry> entries_all = new ArrayList<>();
        ArrayList<BarEntry> entries_cure = new ArrayList<>();
        ArrayList<BarEntry> entries_dead = new ArrayList<>();
        for (int i = 0; i < cityList.size(); i++) {
            entries_all.add(new BarEntry(i, Float.parseFloat(cityList.get(i).getConfirm())));
            entries_cure.add(new BarEntry(i, Float.parseFloat(cityList.get(i).getHeal())));
            entries_dead.add(new BarEntry(i, Float.parseFloat(cityList.get(i).getDead())));
        }
        List<String> citiesName = new ArrayList<>();
        for (int i = 0; i < cityList.size(); i++) {
            citiesName.add(cityList.get(i).getName());
        }

        //X轴设计
        XAxis xAxis = barChart.getXAxis();
        xAxis.setAxisMinimum(0f);
        xAxis.setAxisMaximum(cityList.size());
        xAxis.setValueFormatter(new IndexAxisValueFormatter(citiesName));
        xAxis.setPosition(XAxis.XAxisPosition.BOTTOM);
        xAxis.setDrawAxisLine(false);
        xAxis.setLabelCount(cityList.size());
        xAxis.setCenterAxisLabels(true);

        //Y轴的设计
        YAxis rightY = barChart.getAxisRight();
        YAxis leftY = barChart.getAxisLeft();
        rightY.setEnabled(false);
        leftY.setEnabled(false);

        BarDataSet barDataSet_all = new BarDataSet(entries_all, "确诊人数");
        barDataSet_all.setColor(Color.RED);

        BarDataSet barDataSet_cure = new BarDataSet(entries_cure, "治愈人数");
        barDataSet_cure.setColor(Color.GREEN);

        BarDataSet barDataSet_dead = new BarDataSet(entries_dead, "死亡人数");
        barDataSet_dead.setColor(Color.GRAY);

        BarData barData = new BarData();
        barData.addDataSet(barDataSet_all);
        barData.addDataSet(barDataSet_cure);
        barData.addDataSet(barDataSet_dead);

        barData.setBarWidth(0.3f);
        barData.groupBars(0f, 0.1f, 0f);
        barChart.setData(barData);
    }

}

页面代码

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".HomeChatFragment">

    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <androidx.constraintlayout.widget.Guideline
            android:id="@+id/guideline10"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            app:layout_constraintGuide_percent="0.3" />

        <androidx.constraintlayout.widget.Guideline
            android:id="@+id/guideline9"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            app:layout_constraintGuide_percent="0.2" />

        <androidx.constraintlayout.widget.Guideline
            android:id="@+id/guideline7"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            app:layout_constraintGuide_percent="0.1" />

        <com.github.mikephil.charting.charts.BarChart
            android:id="@+id/barChart"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="@+id/guideline8" />

        <androidx.constraintlayout.widget.Guideline
            android:id="@+id/guideline8"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            app:layout_constraintGuide_percent="0.40" />

        <RadioGroup
            android:id="@+id/radioGroup"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            app:layout_constraintBottom_toTopOf="@+id/guideline7"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.2"
            app:layout_constraintStart_toEndOf="@+id/textViewHeal"
            app:layout_constraintTop_toTopOf="parent">

            <RadioButton
                android:id="@+id/province"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="省份" />

            <RadioButton
                android:id="@+id/city"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="城市" />

            <RadioButton
                android:id="@+id/country"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="国家" />
        </RadioGroup>

        <TextView
            android:id="@+id/textViewHeal"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="请选择查询方式"
            android:textSize="18sp"
            app:layout_constraintBottom_toTopOf="@+id/guideline7"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.05"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent" />

        <TextView
            android:id="@+id/textView2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="请选择查询日期"
            android:textSize="18sp"
            app:layout_constraintBottom_toTopOf="@+id/guideline9"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.05"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="@+id/guideline7" />

        <EditText
            android:id="@+id/queryDate"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:ems="10"
            android:hint="yyyy-MM-dd"
            android:inputType="date"
            app:layout_constraintBottom_toTopOf="@+id/guideline9"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.8"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="@+id/guideline7" />

        <TextView
            android:id="@+id/textView3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="请输入关键字"
            android:textSize="18sp"
            app:layout_constraintBottom_toTopOf="@+id/guideline10"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.05"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="@+id/guideline9" />

        <EditText
            android:id="@+id/keyName"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:ems="10"
            android:hint="请输入要查询的关键字"
            android:inputType="textPersonName"
            app:layout_constraintBottom_toTopOf="@+id/guideline10"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.8"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="@+id/guideline9" />

        <Button
            android:id="@+id/queryButton"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="查询"
            app:layout_constraintBottom_toTopOf="@+id/guideline8"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="@+id/guideline10" />


    </androidx.constraintlayout.widget.ConstraintLayout>


</androidx.constraintlayout.widget.ConstraintLayout>