01Spring-01jdbc 未使用spring代码编写

目录

• pom.xml
• JdbcDemo1.java

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.zjw</groupId>
    <artifactId>day01_eesy_01jdbc</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <dependencies>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.12</version>
        </dependency>

    </dependencies>


</project>

JdbcDemo1.java

package com.zjw;

import com.mysql.cj.jdbc.Driver;

import java.sql.*;

public class JdbcDemo1 {
    public static void main(String[] args) throws SQLException, ClassNotFoundException {
        //注册驱动
//        Driver driver = new Driver();
//        DriverManager.registerDriver(driver);
        Class.forName("com.mysql.cj.jdbc.Driver");
        //获取连接
        Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/eesy_jdbc?useSSL=false&serverTimezone=Asia/Shanghai", "root", "123456");
        System.out.println(connection);
        //获取操作数据库的预处理对象
        PreparedStatement ps = connection.prepareCall("SELECT * FROM account");
        //执行sql,得到结果集
        ResultSet resultSet = ps.executeQuery();
        //遍历结果集
        while (resultSet.next()){
            System.out.println(resultSet.getString("name"));
        }
        //释放资源
        resultSet.close();
        ps.close();
        connection.close();
    }
}

程序问题：
使用了具体的驱动类，如果不存在编译会报错（没导入mysql的jar包）。可以利用反射创建驱动类，解耦合Class.forName（"具体类路径"）