修改pom文件打包方式：

移除tomcat依赖或者将tomcat依赖scope改为provide：

<!-- 方式1 -->
<dependency>
	<groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
    <!-- 移除嵌入式tomcat插件 -->
    <exclusions>
    	<exclusion>
        	<groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-tomcat</artifactId>
        </exclusion>
    </exclusions>
</dependency>

<!-- 方式2 -->
<dependency>
	<groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-tomcat</artifactId>
    <scope>provided</scope>
</dependency>

继承SpringBootServletInitializer，实现configure方法：

• 方式一：引导类继承、实现

  @SpringBootApplication
  public class Application extends SpringBootServletInitializer {
      public static void main(String[] args) {
          SpringApplication.run(Application.class, args);
      }
      
      @Override
      protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
          return bulder.source(Application.class);
      }
  }
  

• 方式二：新增加一个类继承、实现

  public class ServletInitializer extends SpringBootServletInitializer {
      @Override
      protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
          //此处的Application.class为带有@SpringBootApplication注解的引导类
          return bulder.source(Application.class);
      }
  }
  

注意事项：

• 使用外部Tomcat部署访问的时候，application.yml / application.properties中配置的server.port / server.servlet.context-path将失效，请使用tomcat的端口、webapps下项目名进行访问；

• 为防止应用上下文所导致的项目访问资源加载不到的问题，建议pom.xml文件中标签下添加标签：

  <build>
  	<!-- 应与application.properties / application.yml中context-path保持一致 -->
      <fileName>war包名称</fileName>
      <plugins>
      	<plugin>
          	<groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-maven-plugin</artifactId>
          </plugin>
      </plugins>
  </build>