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

从报错中 可以看到 没有连上数据库
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 解决方法
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

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

原因是MySQL版本高,mysql的jar版本低造成mysql与jar的编码错乱引起的,我的MYSQL是8.0版本

MYSQL 5.5 之前, UTF8 编码只支持1-3个字节;从MYSQL5.5开始,可支持4个字节UTF编码utf8mb4;

换成 高版本后 解决问题
Unknown initial character set index ‘255‘ received from server. Initial client character 解决方法