@SpringBootApplication(scanBasePackages = {"com.xxx.*"})
public class ApiApplication extends SpringBootServletInitializer {

    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
        return application.sources(ApiApplication.class);
    }
    public static void main(String[] args) {
        SpringApplication.run(ApiApplication.class, args);
    }
}

<build>
        <plugins>

            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <!-- 指定该Main Class为全局的唯一入口 -->
                    <mainClass>com.xxx.api.ApiApplication</mainClass>
                    <layout>ZIP</layout>
                </configuration>
                <executions>
                    <execution>
                        <goals>
                            <goal>repackage</goal><!--可以把依赖的包都打包到生成的Jar包中-->
                        </goals>
                    </execution>
                </executions>
            </plugin>
            <!--maven打包排除spring-boot内嵌tomcat容器依赖jar-->
            <plugin>
                <artifactId>maven-war-plugin</artifactId>
                <version>3.0.0</version>
                <configuration> 
                    <!--打包后的名称-->
                    <warName>xxx-api</warName>
                    <packagingExcludes>
                        WEB-INF/lib/tomcat-embed-*.jar,
                        WEB-INF/lib/spring-boot-starter-tomcat-*.jar
                    </packagingExcludes>
                </configuration>
            </plugin>            
        </plugins>
    </build>

mvn -pl xxx-api -am install