错误提示：
Caused by: java.lang.IllegalArgumentException: Property 'sqlSessionFactory' or 'sqlSessionTemplate' are required
at org.springframework.util.Assert.notNull(Assert.java:193) ~[spring-core-5.0.6.RELEASE.jar:5.0.6.RELEASE]
at org.mybatis.spring.support.SqlSessionDaoSupport.checkDaoConfig(SqlSessionDaoSupport.java:74) ~[mybatis-spring-1.3.2.jar:1.3.2]
at org.mybatis.spring.mapper.MapperFactoryBean.checkDaoConfig(MapperFactoryBean.java:73) ~[mybatis-spring-1.3.2.jar:1.3.2]
at org.springframework.dao.support.DaoSupport.afterPropertiesSet(DaoSupport.java:44) ~[spring-tx-5.0.6.RELEASE.jar:5.0.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1765) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1702) ~[spring-beans-5.0.6.RELEASE.jar:5.0.6.RELEASE]
... 34 common frames omitted
原因： 缺少druid-spring-boot-starter。【springboot2 应该是默认集成了druid】
解决方案：
在pom.xml文件加入
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.9</version>
</dependency>