其中mapper-locations是
扫描到对应的dao.xml
路径一定要写对，否则的话是跟java层同目录也可以

mybatis:mapper-locations: classpath:xyz/*.xmltype-aliases-package: com.example.demo.model

如果是放到和mapper同目录下，需要在pom.xml中的build中加入

 </build><resources><resource><directory>src/main/java</directory><!--所在的目录--><includes><!--包括目录下的.properties,.xml文件都会扫描到--><include>**/*.properties</include><include>**/*.xml</include></includes><filtering>false</filtering></resource></resources></build>