Java를 사용하여 온라인 시험 시스템의 시험지 분류 기능을 구현하는 방법

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

public class JDBCUtils {
    private static final String DATABASE_URL = "jdbc:mysql://localhost:3306/examdb";
    private static final String DATABASE_USERNAME = "root";
    private static final String DATABASE_PASSWORD = "root";

    public static Connection getConnection() {
        Connection connection = null;
        try {
            Class.forName("com.mysql.cj.jdbc.Driver");
            connection = DriverManager.getConnection(DATABASE_URL, DATABASE_USERNAME, DATABASE_PASSWORD);
        } catch (ClassNotFoundException | SQLException e) {
            e.printStackTrace();
        }
        return connection;
    }

    public static void closeConnection(Connection connection, PreparedStatement statement, ResultSet resultSet) {
        try {
            if (resultSet != null) {
                resultSet.close();
            }
            if (statement != null) {
                statement.close();
            }
            if (connection != null) {
                connection.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

public class CategoryDao {
    public void addCategory(String categoryName) {
        Connection connection = null;
        PreparedStatement statement = null;
        try {
            connection = JDBCUtils.getConnection();
            String sql = "INSERT INTO tbl_category (name) VALUES (?)";
            statement = connection.prepareStatement(sql);
            statement.setString(1, categoryName);
            statement.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JDBCUtils.closeConnection(connection, statement, null);
        }
    }
}

public class ExamCategoryDao {
    public void addExamCategory(int examId, int categoryId) {
        Connection connection = null;
        PreparedStatement statement = null;
        try {
            connection = JDBCUtils.getConnection();
            String sql = "INSERT INTO tbl_exam_category (exam_id, category_id) VALUES (?, ?)";
            statement = connection.prepareStatement(sql);
            statement.setInt(1, examId);
            statement.setInt(2, categoryId);
            statement.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            JDBCUtils.closeConnection(connection, statement, null);
        }
    }
}

public class Test {
    public static void main(String[] args) {
        CategoryDao categoryDao = new CategoryDao();
        ExamCategoryDao examCategoryDao = new ExamCategoryDao();

        // 添加试卷分类
        categoryDao.addCategory("数学");
        categoryDao.addCategory("英语");
        categoryDao.addCategory("物理");

        // 添加试卷分类和试卷的关系
        examCategoryDao.addExamCategory(1, 1); // 将试卷1分类为数学
        examCategoryDao.addExamCategory(2, 2); // 将试卷2分类为英语
        examCategoryDao.addExamCategory(3, 3); // 将试卷3分类为物理
    }
}