안녕하세요 강사님 JettyWebServerFactory Bean생성 하는데서 오류가납니다

 org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'jettyWebServerFactory' defined in class path resource [tobyspring/config/autoconfig/JettyWebServerConfig.class]: Post-processing of merged bean definition failed; nested exception is java.lang.IllegalStateException: Failed to introspect Class [org.springframework.boot.web.embedded.jetty.JettyServletWebServerFactory] from ClassLoader [jdk.internal.loader.ClassLoaders$AppClassLoader@2437c6dc]

이런에러가나구요

package tobyspring.config.autoconfig;

import org.springframework.boot.web.embedded.jetty.JettyServletWebServerFactory;
import org.springframework.boot.web.servlet.server.ServletWebServerFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Condition;
import org.springframework.context.annotation.ConditionContext;
import org.springframework.context.annotation.Conditional;
import org.springframework.core.type.AnnotatedTypeMetadata;
import tobyspring.config.MyAutoConfiguration;

@MyAutoConfiguration
@Conditional(JettyWebServerConfig.JettyCondition.class)
public class JettyWebServerConfig {
@Bean("jettyWebServerFactory")
public ServletWebServerFactory servletWebServerFactory(){
return new JettyServletWebServerFactory();
}

static class JettyCondition implements Condition {
@Override
public boolean matches(ConditionContext context, AnnotatedTypeMetadata metadata) {
return true;
}
}
}

이건 코드입니다 왜 오류가날까요 틀린게없는거같습니다