解决：Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException:

梦里梦外; 2022-12-15 11:18 104阅读 0赞

# 报错信息如下： #

> # org.apache.ibatis.exceptions.PersistenceException: #
> 
> ### Error querying database. Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Client does not support authentication protocol requested by server; consider upgrading MySQL client ###
> 
> ### The error may exist in com/lbl/dao/IPersonDao.xml ###
> 
> ### The error may involve com.lbl.dao.IPersonDao.findAll ###
> 
> ### The error occurred while executing a query ###
> 
> ### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Client does not support authentication protocol requested by server; consider upgrading MySQL client ###
> 
> # org.apache.ibatis.exceptions.PersistenceException: #
> 
> ### Error querying database. Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Client does not support authentication protocol requested by server; consider upgrading MySQL client ###
> 
> ### The error may exist in com/lbl/dao/IPersonDao.xml ###
> 
> ### The error may involve com.lbl.dao.IPersonDao.findAll ###
> 
> ### The error occurred while executing a query ###

MySQL版本和驱动包不兼容的问题

于是我查看了自己的mysql版本

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3OTI0OTA1_size_16_color_FFFFFF_t_70_pic_center]

再看了看自己pom.xml文件的mysql驱动版本

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3OTI0OTA1_size_16_color_FFFFFF_t_70_pic_center 1]

再查看自己连接数据库时，连接的是哪一个版本的数据库

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM3OTI0OTA1_size_16_color_FFFFFF_t_70_pic_center 2]

这就找到了报错的原因了。

# 原因： #

mysql驱动是5.0+版本的，而连接的数据库版本是8.0+版本的，所以连接不上。

解决办法：

1.改连接数据库与mysql驱动版本一致的5.0+版本

2.改mysql驱动为8.0+版本

这里要注意，如果将mysql驱动改为8.0+版本，则还要改驱动的类名,加cj字段

把驱动的类名改为:  
`driver="com.mysql.cj.jdbc.Driver";`

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