如何在JDBC中获取用户输入的语句？

import java.sql.*;
import java.util.Scanner;

public class JDBCExample {
    public static void main(String[] args) {
        try {
            // 建立数据库连接
            Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mydatabase", "username", "password");
            
            // 创建Statement对象
            Statement stmt = conn.createStatement();

            // 获取用户输入
            Scanner scanner = new Scanner(System.in);
            System.out.println("请输入查询语句：");
            String userInput = scanner.nextLine();

            // 构建SQL语句
            String sql = userInput;

            // 执行SQL语句
            ResultSet rs = stmt.executeQuery(sql);

            // 处理查询结果
            while (rs.next()) {
                // 获取结果集中的数据
                String column1Value = rs.getString("column1");
                String column2Value = rs.getString("column2");
                // ...
                System.out.println(column1Value + "\t" + column2Value);
            }

            // 关闭数据库连接
            rs.close();
            stmt.close();
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}