原因是maven打包的时候，没有把XXXmapper.xml 文件编译过来
解决办法：在maven项目的pom.xml添加：
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.xml</include>
<include>**/*.properties</include>
</includes>
</resource>
<!-- <resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.xml</include>
</includes>
</resource> -->
</resources