1、修改pom.xml里的mysql驱动坐标

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

2、修改DemoConfig.java

// 配置 druid 数据库连接池插件
DruidPlugin druidPlugin = new DruidPlugin(PropKit.get("jdbcUrl"), PropKit.get("user"), PropKit.get("password").trim(),"com.mysql.cj.jdbc.Driver");

3、修改a_little_config.txt

jdbcUrl = jdbc:mysql://localhost/jfinal_demo?characterEncoding=utf8&useSSL=false&zeroDateTimeBehavior=CONVERT_TO_NULL&serverTimezone=GMT