Error querying database. Cause: org.springframework.jdbc.CannotGetJdbcConnectionException: Could no

代码移植过程中由于用了新版本的MySQL数据库，版本8+，一直出现如题，连不上数据库的错误。其实就是porm.xml里面版本需要改，还有jdbc.properties里面参数也要改：

    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.12</version>
      <scope>runtime</scope>
    </dependency>

#
#JDBC connection properties
#
jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/dbname?characterEncoding=UTF-8&useSSL=false&serverTimezone=UTC
jdbc.username=root
jdbc.password=