sqlite 如何从toString()方法返回模型类中的所有属性

我尝试在android studio中使用ormlite开发一个简单的crud应用程序。我已经实现了插入和查看部分。我创建了一个列表视图来查看项目。但是在一条记录中只显示一个属性。我想将一条记录的所有属性都显示到列表视图中。我是android开发的初学者。请告诉我如何做。谢谢。：）
首先，我调用模型类中的一个方法

@NonNull
    @Override
    public String toString(){
        return this.courseDescription;
    }

在这个方法中，我只能返回一个属性。我需要返回字符串数据类型的所有属性。
下面是我的代码。
Course.java 模型类）

import androidx.annotation.NonNull;

import com.j256.ormlite.field.DatabaseField;
import com.j256.ormlite.table.DatabaseTable;

@DatabaseTable(tableName = "course")
public class Course {

    @DatabaseField(generatedId = true)
    private int courseId;

    @DatabaseField(columnName = "course_name")
    private String courseName;

    @DatabaseField(columnName = "course_duration")
    private String courseDuration;

    @DatabaseField(columnName = "course_description")
    private String courseDescription;

    public Course() {
    }

    public Course(String courseName, String courseDuration,
                  String courseDescription) {
        this.courseName = courseName;
        this.courseDuration = courseDuration;
        this.courseDescription = courseDescription;
    }

    public int getCourseId() {
        return courseId;
    }

    public void setCourseId(int courseId) {
        this.courseId = courseId;
    }

    public String getCourseName() {
        return courseName;
    }

    public void setCourseName(String courseName) {
        this.courseName = courseName;
    }

    public String getCourseDuration() {
        return courseDuration;
    }

    public void setCourseDuration(String courseDuration) {
        this.courseDuration = courseDuration;
    }

    public String getCourseDescription() {
        return courseDescription;
    }

    public void setCourseDescription(String courseDescription) {
        this.courseDescription = courseDescription;
    }

    @NonNull
    @Override
    public String toString(){
        return this.courseDescription;
    }
}

DBA.java

import android.content.Context;
import android.util.Log;

import com.j256.ormlite.dao.Dao;
import com.j256.ormlite.support.ConnectionSource;
import com.j256.ormlite.table.TableUtils;
import com.oss.datahelper.DataBaseManager;

import java.sql.SQLException;
import java.util.List;

public class DBA<T> {
    private static final int DB_VERSION = 1;
    private Dao<T, Integer> dao;

    public void init(Context context, Class clazz){
        String dbname = context.getApplicationInfo()
                .loadLabel(context.getPackageManager())
                .toString()+".sqlite";

        Log.i("INFO NAME", dbname);

        DataBaseManager.init(context, dbname, DB_VERSION);
        ConnectionSource source = DataBaseManager.getInstance()
                .getHelper()
                .getConnectionSource();

        try{
            TableUtils.createTableIfNotExists(source, clazz);
            this.dao = DataBaseManager.getInstance()
                    .getHelper()
                    .getDao(clazz);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public  Dao<T, Integer> getDao(){
        return dao;
    }

    public T saveCourse(T entity){
        try {
            this.getDao().create(entity);
            return entity;
        } catch (SQLException e) {
            e.printStackTrace();
            return null;
        }
    }

    public List<T> getCourse(){
        try {
            return this.getDao().queryForAll();
        } catch (SQLException e) {
            e.printStackTrace();
            return null;
        }
    }

    public T getCourseByID(int id){
        try {
            return this.getDao().queryForId(id);
        } catch (SQLException e) {
            e.printStackTrace();
            return null;
        }
    }
}

CourseDao.java

import android.content.Context;

import com.ss.ormlite3.Model.Course;

public class CourseDao extends DBA<Course>{
    public CourseDao(Context context){
        init(context,Course.class);
    }
}

MainActivity.java

mport androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;

import com.ss.ormlite3.Database.CourseDao;
import com.ss.ormlite3.Model.Course;
import com.ss.ormlite3.R;

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

public class MainActivity extends AppCompatActivity {

    private EditText courseNameEdt,courseDurationEdt, courseDescriptionEdt;
    private Button addCourseBtn;
    ListView courseListView;
    CourseDao courseDao;

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

        courseNameEdt = findViewById(R.id.idEdtCourseName);
        courseDurationEdt = findViewById(R.id.idEdtCourseDuration);
        courseDescriptionEdt = findViewById(R.id.idEdtCourseDescription);
        addCourseBtn = findViewById(R.id.idBtnAddCourse);
        courseListView = findViewById(R.id.listviewCourse);

        courseDao = new CourseDao(this);
        loadSavedCourses();
    }

    private void loadSavedCourses() {
        List<Course> courses = courseDao.getCourse();
        ArrayAdapter<Course> arrayAdapter = new ArrayAdapter<>(this
                , android.R.layout.simple_list_item_1, courses);

        courseListView.setAdapter(arrayAdapter);
    }

    //private void addCourse(){}

    public void saveNote(View view) {

        try {
            Course course = new Course();
            course.setCourseName(courseNameEdt.getText().toString());
            course.setCourseDuration(courseDurationEdt.getText().toString());
            course.setCourseDescription(courseDescriptionEdt.getText().toString());

            courseDao.saveCourse(course);
            loadSavedCourses();
            Toast.makeText(this, "Data addes", Toast.LENGTH_SHORT).show();
        } catch (Exception e) {
            e.printStackTrace();
            Toast.makeText(this, e.toString(), Toast.LENGTH_SHORT).show();
        }
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".Activity.MainActivity">

    <!--Edit text to enter course name-->
    <EditText
        android:id="@+id/idEdtCourseName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:hint="Enter course Name"
        android:minHeight="48dp" />

    <!--edit text to enter course duration-->
    <EditText
        android:id="@+id/idEdtCourseDuration"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:hint="Enter Course Duration"
        android:minHeight="48dp" />

    <!--edit text for course description-->
    <EditText
        android:id="@+id/idEdtCourseDescription"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:hint="Enter Course Description"
        android:minHeight="48dp" />

    <!--button for adding new course-->
    <Button
        android:id="@+id/idBtnAddCourse"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:text="Add Course"
        android:textAllCaps="false"
        android:onClick="saveNote"/>

    <ListView
        android:id="@+id/listviewCourse"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

sqlite 如何从toString()方法返回模型类中的所有属性

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