Mysql

spring常用dataSource配置如下:

spring:
  datasource:
    username: root
    password: root
    url: jdbc:mysql://localhost:3306/datamiddle?characterEncoding=utf8&useSSL=true&rewriteBatchedStatements=true
    driver-class-name: com.mysql.jdbc.Driver # 或 `com.mysql.cj.jdbc.Driver

而driver-class-name的com.mysql.jdbc.Driver与com.mysql.cj.jdbc.Driver有什么区别呢?

区别是：com.mysql.jdbc.Driver是mysql-connector-java 5版本的驱动名称，5版本之后替换为com.mysql.cj.jdbc.Driver。

当5之后的版本选择com.mysql.jdbc.Driver的时候，会有警告提示，替换为com.mysql.cj.jdbc.Driver

查看源码可知，老版本的Driver 继承了新版本的Driver，通过继承的方式兼容老版本，并添加了告警提示，如下:

public class Driver extends com.mysql.cj.jdbc.Driver {
    public Driver() throws SQLException {
    }

    static {
        System.err.println("Loading class `com.mysql.jdbc.Driver'. This is deprecated. The new driver class is `com.mysql.cj.jdbc.Driver'. The driver is automatically registered via the SPI and manual loading of the driver class is generally unnecessary.");
    }
}