思路

1. 构建项目
2. 导入jdbc驱动类。
3. 创建连接
4. 查询数据

实例：

package org.example;
import org.gjt.mm.mysql.Driver;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;
public class Main {
    public static void main(String[] args) throws SQLException {
        Driver driver = new Driver();
        Properties properties = new Properties();
        properties.setProperty("user","root");
        properties.setProperty("password","123456");
        Connection connect = driver.connect("jdbc:mysql://localhost:3306/kettle?createDatabaseIfNotExist=true&useSSL=false", properties);
        Statement stmt = connect.createStatement();
        ResultSet data = stmt.executeQuery("select 100 as va;");
        while (data.next()){
            System.out.println(data.getString("va"));
        }
        connect.close();
    }
}