switching to a different HTTP server, you need to exclude the default dependencies in addition to including the one you need. To help with this process, Spring Boot provides a separate starter for each of the supported HTTP servers.
<properties> <servlet-api.version>3.1.0</servlet-api.version> </properties> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> <exclusions> <!-- Exclude the Tomcat dependency --> <exclusion> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-tomcat</artifactId> </exclusion> </exclusions> </dependency> <!-- Use Jetty instead --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-jetty</artifactId> </dependency> ... The version of the Servlet API has been overridden as, unlike Tomcat 9 and Undertow 2.0, Jetty 9.4 does not support Servlet 4.0. To scan for a free port (using OS natives to prevent clashes) use server.port=0