如何基于SpringBoot部署外部Tomcat过程解析

<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-web</artifactId>
  <exclusions><!-- 移除嵌入式tomcat插件 -->
    <exclusion>
    <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-tomcat</artifactId>
    </exclusion>
   </exclusions>
</dependency>

<!-- 如果使用第三方tomcat请增加scope -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-tomcat</artifactId>
    <scope>provided</scope>
</dependency>

@SpringBootApplication
public class DemoApplication extends SpringBootServletInitializer {

  public static void main(String[] args) {
    SpringApplication.run(DemoApplication.class, args);
  }

  @Override
  protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
    return builder.sources(DemoApplication.class);
  }
}