Android studio连接到MySQL工作台，模拟器不断崩溃。显示错误未找到类“java.sql.SQLType”

Question

我是安卓工作室的新手。MySQL工作台中的服务器无法启动（单击“启动服务器”后，工作台将不响应），因此我使用xampp

起初，我遇到了问题，没有找到类“java.sql.SQLType”。在我搜索之后，我发现大多数人说mysql connector 8.0.13的版本太高，所以我按照给出的解决方案将其降级为5.1.49版本，但emulator show“java.lang.ClassNotFoundException:com.mysql.jdbc.Driver”

• Android gradle插件版本4.1.3
• 渐变版本6.5
• SDK版本Android 11.0
• JavaVersion1_8

这是我的主要活动。java

package com.example.安卓_mysql;

import 安卓.os.AsyncTask;
import 安卓.os.Bundle;
import 安卓.view.View;
import 安卓.widget.Button;
import 安卓.widget.TextView;

import 安卓x.appcompat.app.AppCompatActivity;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;


public class MainActivity extends AppCompatActivity {

    TextView text, errorText;
    Button show;

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

        text = (TextView) findViewById(R.id.textView);
        errorText = (TextView) findViewById(R.id.textView2);
        show = (Button) findViewById(R.id.button);

        show.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Task retrieveData = (Task) new Task().execute();
            }
        });
    }

    class Task extends AsyncTask<Void, Void, Void> {
        String records = "", error = "";

        @Override
        protected Void doInBackground(Void... voids) {
            Connection conn = null;
            Statement stmt = null;

            try {
                Class.forName("com.mysql.jdbc.Driver");
                conn = DriverManager.getConnection("jdbc:mysql://192.168.0.111:3306/mydb", "root", "1234");
                //conn = DriverManager.getConnection("jdbc:mysql://192.168.0.124:3306/安卓","andro","1234");
                stmt = conn.createStatement();
                ResultSet rs = stmt.executeQuery("Select * FROM testing123");
                //ResultSet resultSet = statement.executeQuery("Select * FROM table_name");

                while (rs.next()) {
                    records += rs.getString(1) + " " + rs.getString(2) + "\n";
                }
            } catch (Exception e) {
                error = e.toString();
            }
            return null;
        }

        @Override
        protected void onPostExecute(Void aVoid) {
            text.setText(records);
            if (error != "")
                errorText.setText(error);
            super.onPostExecute(aVoid);
        }
    }
}

这是我的主要活动。xml

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

    <TextView
        安卓:id="@+id/textView"
        安卓:layout_width="wrap_content"
        安卓:layout_height="wrap_content"
        安卓:text="TextView"
        安卓:textSize="24sp"
        app:layout_constraintBottom_toTopOf="@+id/button"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        安卓:id="@+id/button"
        安卓:layout_width="wrap_content"
        安卓:layout_height="wrap_content"
        安卓:text="Show Records"
        安卓:textSize="24sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        安卓:id="@+id/textView2"
        安卓:layout_width="wrap_content"
        安卓:layout_height="wrap_content"
        安卓:text="No Error"
        安卓:textSize="24sp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/button" />
</安卓x.constraintlayout.widget.ConstraintLayout>

这是我的logcat

2021-04-30 16:26:31.527 217-221/? E/安卓.system.suspend@1.0-service: Error opening kernel wakelock stats for: wakeup34: Permission denied
2021-04-30 16:26:31.536 217-221/? E/安卓.system.suspend@1.0-service: Error opening kernel wakelock stats for: wakeup35: Permission denied
2021-04-30 16:26:31.532 217-217/? W/Binder:217_2: type=1400 audit(0.0:56): avc: denied { read } for name="wakeup35" dev="sysfs" ino=18817 scontext=u:r:system_suspend:s0 tcontext=u:object_r:sysfs:s0 tclass=dir permissive=0
2021-04-30 16:26:33.679 1560-6762/com.google.安卓.gms I/Vision: Requesting optional module download of ocr.
2021-04-30 16:26:33.679 1560-6762/com.google.安卓.gms I/Vision: Checking for download completion for 574061 -- ocr
2021-04-30 16:26:36.143 486-486/? E/netmgr: qemu_pipe_open_ns:62: Could not connect to the 'pipe:qemud:network' service: Invalid argument
2021-04-30 16:26:36.143 486-486/? E/netmgr: Failed to open QEMU pipe 'qemud:network': Invalid argument
2021-04-30 16:26:36.264 503-503/? E/wifi_forwarder: qemu_pipe_open_ns:62: Could not connect to the 'pipe:qemud:wififorward' service: Invalid argument
2021-04-30 16:26:36.264 503-503/? E/wifi_forwarder: RemoteConnection failed to initialize: RemoteConnection failed to open pipe
2021-04-30 16:26:43.707 1560-6764/com.google.安卓.gms I/Vision: Requesting optional module download of ocr.
2021-04-30 16:26:43.708 1560-6764/com.google.安卓.gms I/Vision: Checking for download completion for 584090 -- ocr
2021-04-30 16:26:47.691 217-221/? E/安卓.system.suspend@1.0-service: Error opening kernel wakelock stats for: wakeup34: Permission denied
2021-04-30 16:26:47.684 217-217/? W/Binder:217_2: type=1400 audit(0.0:57): avc: denied { read } for name="wakeup34" dev="sysfs" ino=18754 scontext=u:r:system_suspend:s0 tcontext=u:object_r:sysfs:s0 tclass=dir permissive=0
2021-04-30 16:26:47.707 217-221/? E/安卓.system.suspend@1.0-service: Error opening kernel wakelock stats for: wakeup35: Permission denied