Full error:

The problem revolves around mapper. There may be many reasons for the problem:

1. The control document is written incorrectly

2. The file generated after compilation does not contain XML file

Solution: manually specify the resource folder in the pop file

<!--        Manually specify the resource folder-->
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <includes>
                    <include>**/*.xml</include>
                </includes>
            </resource>
        </resources>