2.升级mysql-connector 5到8遇到的问题

摘自：http://mangocool.com/1535426841921.html

1、Establishing SSL connection without server's identity verification is not recommend

解决办法：

在mysql连接字符串url中加入ssl=true或者false即可，如下：

 url=jdbc:mysql://xxx.xxx.xxx.xxx:3306/xxx?

characterEncoding=utf8

&useSSL=true

参考：

https://blog.csdn.net/guoweimelon/article/details/50810399

2、The server time zone value

'Öйú±ê׼ʱ¼ä' is unrecognized or represents more than one time zone.

You must configure either the server or JDBC driver (via the

serverTimezone configuration property) to use a more specifc time zone

value if you want to utilize time zone support. 

解决办法：

 在mysql连接字符串url中加入serverTimezone=UTC即可，如下：

   url=jdbc:mysql://xxx.xxx.xxx.xxx:3306/xxx?      

  characterEncoding=utf8

  &useSSL=true

  &serverTimezone=UTC

参考：

https://blog.csdn.net/yefengzhichen/article/details/51834511

3、java.sql.SQLException: The connection

property 'zeroDateTimeBehavior' acceptable values are:

'CONVERT_TO_NULL', 'EXCEPTION' or 'ROUND'. The value 'convertToNull' is

not acceptable.

java.lang.IllegalArgumentException: No enum constant com.mysql.cj.conf.PropertyDefinitions.ZeroDatetimeBehavior.CONVERTTONULL

解决办法：

由于MySql废弃了convertToNull该写法，改为 CONVERT_TO_NULL

 url=jdbc:mysql://xxx.xxx.xxx.xxx:3306/xxx?characterEncoding=utf8

&useSSL=true

&serverTimezone=UTC

&zeroDateTimeBehavior=CONVERT_TO_NULL

参考：

https://blog.csdn.net/qq_32454537/article/details/80109800

4、Exception in thread "main"

org.springframework.beans.factory.parsing.BeanDefinitionParsingException:

Configuration problem: Unable to locate Spring NamespaceHandler for XML

schema namespace [http://www.springframework.org/schema/context]

Offending resource: class path resource [spring-mybatis.xml]

参考：http://chenzhou123520.iteye.com/blog/1971322

5、Caused by: java.lang.UnsupportedClassVersionError: com/mysql/jdbc/Driver : Unsupported major.minor version 52.0

解决办法：

mysql8 依赖jdk1.8，升级jdk

6、Path does not chain with any of the trust anchors

解决办法：

应该是证书问题，把useSSL=true改为useSSL=false就好了。

参考：

https://blog.csdn.net/u013727805/article/details/80555726