3.0.0-M1: ClassNotFoundException: Jackson2HalModule (spring-boot-4.0.0-RC1)

[zyro23]

Describe the bug

trying to use springdoc-openapi-starter-webmvc-ui 3.0.0-M1 with spring-boot-4.0.0-RC1 (and spring-boot-starter-hateoas) fails with java.lang.ClassNotFoundException: org.springframework.hateoas.mediatype.hal.Jackson2HalModule.

To Reproduce
Steps to reproduce the behavior:

• spring-boot 4.0.0-RC1
• springdoc-openapi-starter-webmvc-ui 3.0.0-M1
• spring-boot-starter-data-rest
• spring-boot-starter-hateoas
• spring-boot-starter-webmvc
• run

stacktrace (collapsed)

2025-10-24T13:40:30.442+02:00 ERROR 35768 --- [demo] [           main] o.s.boot.SpringApplication               : Application run failed

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'modelConverterRegistrar' defined in class path resource [org/springdoc/core/configuration/SpringDocConfiguration.class]: Unsatisfied dependency expressed through method 'modelConverterRegistrar' parameter 0: Error creating bean with name 'collectionModelContentConverter' defined in class path resource [org/springdoc/core/configuration/SpringDocHateoasConfiguration.class]: Unsatisfied dependency expressed through method 'collectionModelContentConverter' parameter 0: Error creating bean with name 'halProvider' defined in class path resource [org/springdoc/core/configuration/SpringDocDataRestConfiguration.class]: Failed to instantiate [org.springdoc.core.providers.DataRestHalProvider]: Factory method 'halProvider' threw exception with message: org/springframework/hateoas/mediatype/hal/Jackson2HalModule
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:804) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:546) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1363) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:566) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:526) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:333) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:371) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:331) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:196) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.instantiateSingleton(DefaultListableBeanFactory.java:1218) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingleton(DefaultListableBeanFactory.java:1184) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:1121) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:983) ~[spring-context-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:620) ~[spring-context-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.boot.web.server.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:143) ~[spring-boot-web-server-4.0.0-RC1.jar:4.0.0-RC1]
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:765) ~[spring-boot-4.0.0-RC1.jar:4.0.0-RC1]
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:454) ~[spring-boot-4.0.0-RC1.jar:4.0.0-RC1]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:321) ~[spring-boot-4.0.0-RC1.jar:4.0.0-RC1]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1374) ~[spring-boot-4.0.0-RC1.jar:4.0.0-RC1]
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:1363) ~[spring-boot-4.0.0-RC1.jar:4.0.0-RC1]
	at com.example.demo.DemoApplication.main(DemoApplication.java:10) ~[main/:na]
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'collectionModelContentConverter' defined in class path resource [org/springdoc/core/configuration/SpringDocHateoasConfiguration.class]: Unsatisfied dependency expressed through method 'collectionModelContentConverter' parameter 0: Error creating bean with name 'halProvider' defined in class path resource [org/springdoc/core/configuration/SpringDocDataRestConfiguration.class]: Failed to instantiate [org.springdoc.core.providers.DataRestHalProvider]: Factory method 'halProvider' threw exception with message: org/springframework/hateoas/mediatype/hal/Jackson2HalModule
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:804) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:546) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1363) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:566) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:526) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:333) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:371) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:331) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:201) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:229) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.addCandidateEntry(DefaultListableBeanFactory.java:2007) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1971) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveMultipleBeanCollection(DefaultListableBeanFactory.java:1863) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveMultipleBeans(DefaultListableBeanFactory.java:1833) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1711) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.createOptionalDependency(DefaultListableBeanFactory.java:2350) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1635) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:912) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:791) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	... 21 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'halProvider' defined in class path resource [org/springdoc/core/configuration/SpringDocDataRestConfiguration.class]: Failed to instantiate [org.springdoc.core.providers.DataRestHalProvider]: Factory method 'halProvider' threw exception with message: org/springframework/hateoas/mediatype/hal/Jackson2HalModule
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:657) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:645) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1363) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1195) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:566) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:526) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:333) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:371) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:331) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:201) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveBean(DefaultListableBeanFactory.java:1225) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1704) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1651) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:912) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:791) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	... 40 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springdoc.core.providers.DataRestHalProvider]: Factory method 'halProvider' threw exception with message: org/springframework/hateoas/mediatype/hal/Jackson2HalModule
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.lambda$instantiate$0(SimpleInstantiationStrategy.java:183) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiateWithFactoryMethod(SimpleInstantiationStrategy.java:72) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:152) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:653) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	... 54 common frames omitted
Caused by: java.lang.NoClassDefFoundError: org/springframework/hateoas/mediatype/hal/Jackson2HalModule
	at org.springdoc.core.configuration.SpringDocDataRestConfiguration.halProvider(SpringDocDataRestConfiguration.java:101) ~[springdoc-openapi-starter-common-3.0.0-M1.jar:3.0.0-M1]
	at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
	at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.lambda$instantiate$0(SimpleInstantiationStrategy.java:155) ~[spring-beans-7.0.0-RC2.jar:7.0.0-RC2]
	... 57 common frames omitted
Caused by: java.lang.ClassNotFoundException: org.springframework.hateoas.mediatype.hal.Jackson2HalModule
	at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641) ~[na:na]
	at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188) ~[na:na]
	at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:526) ~[na:na]
	... 61 common frames omitted

Expected behavior

• app starts

Screenshots
n/a

Additional context

seems Jackson2HalModule has been renamed/moved to HalJacksonModule

sample app will be referenced asap.

thanks & regards.

[almothafar-maf]

This is annoying as it is the same for anything above 4.0.0-M2, I'm stuck with that version because of this springdoc-openapi-starter-webmvc-ui which is released 2 months ago.

This is also reported 1 month ago #3095 with the same issue

[zyro23]

fwiw, i was able to at least start my app somehow (to continue upgrading to boot-4.0.0-RC1) using:

springdoc:
  enable-data-rest: false
  enable-hateoas: false

[almothafar-maf]

fwiw, i was able to at least start my app somehow (to continue upgrading to boot-4.0.0-RC1) using:

springdoc:
enable-data-rest: false
enable-hateoas: false

I did this, didn't work, still the same issue.

Strange even I can see it in the source:

@Lazy(false)
@Configuration(proxyBeanMethods = false)
@ConditionalOnExpression("${springdoc.api-docs.enabled:true} and ${springdoc.enable-hateoas:true}")
@ConditionalOnClass(LinkRelationProvider.class)
@ConditionalOnWebApplication
@ConditionalOnBean(SpringDocConfiguration.class)
public class SpringDocHateoasConfiguration {

Edit: Nevermind, I was changing the invalid one lol