项目启动是报错：
org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.boot.autoconfigure.web.servlet.ServletWebServerFactoryConfiguration$EmbeddedTomcat': Initialization of bean failed; nested exception is java.lang.NoClassDefFoundError: org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerAdapter
添加引用：
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>