java.lang.ClassNotFoundException: jakarta.servlet.http.HttpSessionContext with Spring Boot 3 and Jetty server - spring

Question

I community, I'm trying to run a small example with Spring boot 3 and Jetty server before upgrading the production code but I'm getting this error java.lang.ClassNotFoundException: jakarta.servlet.http.HttpSessionContext and the services does not start. This is my Gradle config.
plugins {
id 'java'
id 'idea'
id 'org.springframework.boot' version '3.0.1'
id 'io.spring.dependency-management' version '1.1.0'
}
idea {
module {
downloadJavadoc = false
downloadSources = false
}
}
group = 'com.example'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = '17'
configurations {
compileOnly {
extendsFrom annotationProcessor
}
}
repositories {
mavenCentral()
}
dependencies {
implementation 'org.springframework.boot:spring-boot-starter-security'
implementation 'org.springframework.boot:spring-boot-starter-jetty'
implementation('org.springframework.boot:spring-boot-starter-web') {
exclude group: 'org.springframework.boot', module: 'spring-boot-starter-tomcat'
}
compileOnly 'org.projectlombok:lombok'
annotationProcessor 'org.projectlombok:lombok'
testImplementation 'org.springframework.boot:spring-boot-starter-test'
}
tasks.named('test') {
useJUnitPlatform()
}
and the dependeincies.
HttpSessionContext class no longer exists but somehow, the latest version Jetty still depends on it.
I'm expecting to make it run with Jetty without migrating to another server.

Answer 1

As Jaokim Erdfelt already mentioned, Spring Boot 3 rely on Jakarta Servlet 6.0.0 (see https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-3.0-Release-Notes) and the spring-boot-starter-jetty includes Jetty 11 which is build on Jakarta Servlet 5.0.0 (see https://java.libhunt.com/jetty-project-changelog/11.0.0). So this is an Issue in the starter itself.
To use jetty you have to downgrade the jakarta-servlet version (see https://github.com/spring-projects/spring-boot/wiki/Spring-Boot-3.0-Migration-Guide#jetty) setting
ext["jakarta-servlet.version"] = "5.0.0"

Answer 2

Spring 3 is for Servlet 6 which is available in Jetty 12+