1.在pom文件中排除内嵌Tomcat
方式1：

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

方式2：

 <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>

2.在pom文件中加入打包方式

 <packaging>war</packaging>

3.设置无web.xml时打war包

<build>
  <plugins>
    <plugin>
      <artifactId>maven-war-plugin</artifactId>
      <version>2.6</version>
      <configuration>
        <failOnMissingWebXml>false</failOnMissingWebXml>                        
      </configuration>
    </plugin>
  </plugins>
</build>

4.修改主启动类

@SpringBootApplication
public class Application extends SpringBootServletInitializer {

	@Override
	protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
		return application.sources(Application.class);
	}

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

}

5.使用mav-package命令打包
注：最好先使用mav-clean命令