<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-tomcat</artifactId>
    <version>2.5.3</version>
    <scope>provided</scope>
</dependency>

在启动类同级目录下创建新的类

package net.lesscoding;

import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;

/**
 * @author eleven
 * @date 2021/8/15 19:58
 * @apiNote war包启动类
 */
public class SpringBootStarterApplication extends SpringBootServletInitializer {
    @Override
    protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
        return builder.sources(NginxDemoApplication.class);
    }
}