获取数据库连接的方式五

https://www.bilibili.com/video/BV1eJ411c7rf?p=11

将连接数据库要用到的基本信息外部化到配置文件中，通过读取配置文件的方式获取连接

外部化的配置文件：resources\jdbc.properties

user=root
password=123456
url=jdbc:mysql://localhost:3306/guns
driverClass=com.mysql.cj.jdbc.Driver

import org.junit.Test;

import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.Properties;

public class ConnectionTest5 {

    @Test
    public void testConnection() throws SQLException, ClassNotFoundException, IOException {

        //1.读取配置文件中的4个基本信息
        InputStream is = ConnectionTest5.class.getClassLoader().getResourceAsStream("jdbc.properties");

        Properties pros = new Properties();

        pros.load(is);

        String user = pros.getProperty("user");

        String password = pros.getProperty("password");

        String url = pros.getProperty("url");

        String driverClass = pros.getProperty("driverClass");

        System.out.println(user);

        System.out.println(password);

        System.out.println(url);

        System.out.println(driverClass);

        //2.加载驱动
        Class.forName(driverClass);

        //3.获取连接
        Connection conn = DriverManager.getConnection(url, user, password);

        System.out.println(conn);

    }

}

root
123456
jdbc:mysql://localhost:3306/guns
com.mysql.cj.jdbc.Driver
com.mysql.cj.jdbc.ConnectionImpl@147ed70f

这种方案的好处是解耦了配置参数与业务逻辑实现

https://github.com/jihch/jdbc/blob/main/src/main/java/io/github/jihch/connection/ConnectionTest5.java