WARN: Establishing SSL connection without server's identity verification is not recommended.
<property name="url" value="jdbc:mysql://localhost:3306/ssm/>改为
<property name="url" value="jdbc:mysql://localhost:3306/ssm?useUnicode=true&characterEncoding=utf-8&useSSL=false"/>
来源:https://www.cnblogs.com/wang615/p/12019240.html