I'm trying to get the basic websocket working in Spring with Jetty, as covered here.

At the time of the upgrade, runtime is reporting that the provider is null.

java.lang.NullPointerException: Cannot invoke ".eclipse.jetty.ee10.websocket.server.JettyWebSocketServerContainer.upgrade(.eclipse.jetty.ee10.websocket.server.JettyWebSocketCreator, jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse)" because "container" is null
.springframework.web.socket.server.jetty.JettyRequestUpgradeStrategy.upgrade(JettyRequestUpgradeStrategy.java:117)
...

Please suggest what may be missing. There is a myriad of conflicting spring/jetty/Jakarta/ee10 content with very little examples of plain websocket in Spring.

Do I need to use Customizer to set the handler?

main:

@EnableWebMvc
@SpringBootApplication
public class MyBootApplication...


MyWebSocketConfig class: 

import .springframework.beans.factory.annotation.Autowired;
import .springframework.boot.web.embedded.jetty.JettyServletWebServerFactory;
import .springframework.context.annotation.Bean;
import .springframework.context.annotation.Configuration;
import .springframework.web.socket.config.annotation.EnableWebSocket;
import .springframework.web.socket.config.annotation.WebSocketConfigurer;
import .springframework.web.socket.config.annotation.WebSocketHandlerRegistry;
import .springframework.web.socket.server.jetty.JettyRequestUpgradeStrategy;
import .springframework.web.socket.server.support.DefaultHandshakeHandler;

@Configuration
@EnableWebSocket
public class MyWebSocketConfig implements WebSocketConfigurer {

  @Autowired
  private MyWebSocketHandler myWebSocketHandler;

  @Override
  public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
    registry
        .addHandler(myWebSocketHandler, "/init")
        .setHandshakeHandler(handshakeHandler())
        .setAllowedOrigins("*");
  }

  @Bean
  public DefaultHandshakeHandler handshakeHandler() {

    JettyRequestUpgradeStrategy strategy = new JettyRequestUpgradeStrategy();
    strategy.addWebSocketConfigurer(configurable -> {
       configurable.setInputBufferSize(8192);
       configurable.setIdleTimeout(Duration.ofSeconds(600));
    });
        
    return new DefaultHandshakeHandler(strategy);
  }
}

gradle deps

implementation '.springframework:spring-web:6.2.1'
implementation '.springframework:spring-orm:6.2.1'
implementation '.springframework:spring-aop:6.2.1'
implementation '.springframework:spring-tx:6.2.1'
implementation '.springframework:spring-beans:6.2.1'
implementation '.springframework:spring-core:6.2.1'
implementation '.springframework:spring-jcl:6.2.1'
implementation '.springframework:spring-expression:6.2.1'
implementation '.springframework:spring-jdbc:6.2.1'
implementation '.springframework:spring-webmvc:6.2.1'
implementation '.springframework:spring-context:6.2.1'
implementation '.springframework:spring-websocket:6.2.1'

implementation '.springframework.data:spring-data-jpa:3.3.3'
implementation '.springframework.data:spring-data-commons:3.3.3'

implementation '.springframework.security:spring-security-core:6.3.6'
implementation '.springframework.security:spring-security-web:6.3.6'
implementation '.springframework.security:spring-security-config:6.3.6'

implementation '.springframework.boot:spring-boot-starter-web:3.3.7'
implementation(".springframework.boot:spring-boot-starter-jetty:3.3.7") {
  exclude group: ".springframework.boot", module: "spring-boot-starter-tomcat"
}
implementation '.springframework.boot:spring-boot-starter-data-jpa:3.3.7'
implementation '.springframework.boot:spring-boot-starter-cache:3.3.7'
implementation '.springframework.boot:spring-boot-starter-log4j2:3.3.7'
implementation '.springframework.boot:spring-boot-starter-websocket:3.3.7'

implementation '.springframework.boot:spring-boot-autoconfigure:3.3.7'
implementation '.springframework.boot:spring-boot-actuator-autoconfigure:3.3.7'

Tried a number of different dependencies, results vary from "no JSR-356 compatible provider found..." to this null provider.