一、移除内置Tomcat

将spring-boot-starter-web
依赖中的tomcat移除

<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>

二、添加servlet依赖

<!--添加servlet的依赖-->
<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>3.1.0</version>
    <scope>provided</scope>
</dependency>

三、打包方式改为war包

<packaging>war</packaging>

四、修改SpringBoot启动类

1. 启动类继承SpringBootServletInitializer

2. 重写configure

3. 处理文件过大上传失败的问题（非必须）

public class JieyueApplication extends SpringBootServletInitializer {

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

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

    /**
     * <p>处理文件过大上传失败的问题</p>
     */
    @Bean
    public TomcatServletWebServerFactory containerFactory() {
        return new TomcatServletWebServerFactory() {
            protected void customizeConnector(Connector connector) {
                int maxSize = 50000000;
                super.customizeConnector(connector);
                connector.setMaxPostSize(maxSize);
                connector.setMaxSavePostSize(maxSize);
                if (connector.getProtocolHandler() instanceof AbstractHttp11Protocol) {
                    ((AbstractHttp11Protocol <?>) connector.getProtocolHandler()).setMaxSwallowSize(maxSize);
                    logger.info("Set MaxSwallowSize "+ maxSize);
                }
            }
        };
    }
}