<dependency>

            <groupId>org.springframework.boot</groupId>

            <artifactId>spring-boot-starter-web</artifactId>

            <exclusions>

                <!-- 切换log4j2日志读取 -->

                <exclusion>

                    <groupId>org.springframework.boot</groupId>

                    <artifactId>spring-boot-starter-logging</artifactId>

                </exclusion>

                <!-- 剔除内置tomcat -->

                <exclusion>

                    <groupId>org.springframework.boot</groupId>

                    <artifactId>spring-boot-starter-tomcat</artifactId>

                </exclusion>

            </exclusions>

        </dependency>

 <!--增加tomcat servlet-->

        <dependency>

            <groupId>org.apache.tomcat</groupId>

            <artifactId>tomcat-servlet-api</artifactId>

            <version>8.0.36</version>

            <scope>provided</scope>

        </dependency>

public class SpringBootStartApplication extends SpringBootServletInitializer {

    @Override

    protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {

        // 注意这里要指向原先用main方法执行的Application启动类

        return builder.sources(Demo001Application.class);

    }

}