之前试过springboot 1.5.6版本整合mybatis，pom依赖如下：
<!-- mybatis start -->
<dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>1.0.0</version>
</dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId>
</dependency><dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId><version>1.2.5</version>
</dependency>
<!-- mybatis end -->后来springboot升级到2.0.6，依然沿用这个pom依赖，启动一直报错，
Failed to parse mapping resource: 'class path resource [mapper/xml/*.xml]'; nested exception is java.io.FileNotFoundException: class path resource [mapper/xml/*.xml] cannot be opened because it does not exist原因：
<dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId><version>1.2.5</version>
</dependency>这个依赖的version号太低了，直接删除version即可
<dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId>
</dependency>或者用以下依赖:
<!-- mybatis start -->
<dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>1.3.2</version>
</dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId>
</dependency><!-- alibaba的druid数据库连接池 -->
<dependency><groupId>com.alibaba</groupId><artifactId>druid-spring-boot-starter</artifactId><version>1.1.9</version>
</dependency>
<!-- mybatis end -->