Maven packaging error: Unable to find main class

Multi-module development maven packaging error: Unable to find main class
put the parent module pom.xml

<build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

Comment out, the
reason: the default springboot project has a startup class, but some projects such as the common project do not need a startup class, and there is no startup class