MySQL8：Unknown initial character set index ‘255‘ received from server. Initial client character 解决方法

Unknown initial character set index '255' received from server. Initial client character set can be forced via the 'characterEncoding' property.

从错误的提示信息中发现字符集设置出现问题

mysql连接数据库时报此错误：

//String url = "jdbc:mysql://localhost:3306/mybatis" 如果使用这句就会报错。
//Unknown initial character set index '255' received from server. Initial client character set can be forced via the 'characterEncoding' property.
String url = "jdbc:mysql://localhost:3306/mybatis?useUnicode=true&characterEncoding=utf8";//改成这句，就可以了

最终解决方法：

删除 \WebContent\WEB-INF\lib目录下的。mysql-connector的jar文件。原因是：MySQL驱动和数据库字符集设置不搭配