java.lang.IllegalStateException: Unable to read meta-data for class while implementing open api with spring boot

Question

I am trying to implement Open API Doc and Open API UI using Spring inside Spring Boot:

I am referring following guide to do so: https://www.baeldung.com/spring-rest-openapi-documentation

Dependencies in maven are as follows:

        <!-- https://mvnrepository.com/artifact/org.springdoc/springdoc-openapi-core -->
        <dependency>
            <groupId>org.springdoc</groupId>
            <artifactId>springdoc-openapi-core</artifactId>
            <version>1.1.49</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springdoc/springdoc-openapi-ui -->
        <dependency>
            <groupId>org.springdoc</groupId>
            <artifactId>springdoc-openapi-ui</artifactId>
            <version>1.2.20</version>
        </dependency>

Spring Boot Version that I am using is 2.2

I am getting following metadata related error while running application via ./mvnw spring-boot:run

java.lang.IllegalStateException: Unable to read meta-data for class org.springdoc.core.MultipleOpenApiSupportConfiguration
        at org.springframework.boot.autoconfigure.AutoConfigurationSorter$AutoConfigurationClass.getAnnotationMetadata(AutoConfigurationSorter.java:233) ~[spring-boot-autoconfigure-2.2.2.RELEASE.jar:2.2.2.RELEASE]
        at org.springframework.boot.autoconfigure.AutoConfigurationSorter$AutoConfigurationClass.getOrder(AutoConfigurationSorter.java:204) ~[spring-boot-autoconfigure-2.2.2.RELEASE.jar:2.2.2.RELEASE]
        at org.springframework.boot.autoconfigure.AutoConfigurationSorter$AutoConfigurationClass.access$000(AutoConfigurationSorter.java:150) ~[spring-boot-autoconfigure-2.2.2.RELEASE.jar:2.2.2.RELEASE]
        at org.springframework.boot.autoconfigure.AutoConfigurationSorter.lambda$getInPriorityOrder$0(AutoConfigurationSorter.java:63) ~[spring-boot-autoconfigure-2.2.2.RELEASE.jar:2.2.2.RELEASE]
        at java.base/java.util.TimSort.countRunAndMakeAscending(TimSort.java:360) ~[na:na]
        at java.base/java.util.TimSort.sort(TimSort.java:234) ~[na:na]
        at java.base/java.util.Arrays.sort(Arrays.java:1516) ~[na:na]

Any clue why it is happening?

Answer 1

springdoc-openapi-ui has springdoc-openapi-core as a transitive dependency. It is safest to only define the deepest dependency, and let it pull the correct versions of its upstream libraries, like so:

<dependency>
    <groupId>org.springdoc</groupId>
    <artifactId>springdoc-openapi-ui</artifactId>
    <version>${springdoc-openapi-ui.version}</version>
</dependency>

In other words, leave out springdoc-openapi-core from your POM dependencies, and only specify the above (replacing ${springdoc-openapi-ui.version} with your desired version, of course).

Answer 2

I had the same problem, here the full stack trace:

24-12-2019 15:51:45.312 [restartedMain] ERROR o.s.boot.SpringApplication.reportFailure - Application run failed
java.lang.IllegalStateException: Unable to read meta-data for class org.springdoc.core.MultipleOpenApiSupportConfiguration
    at org.springframework.boot.autoconfigure.AutoConfigurationSorter$AutoConfigurationClass.getAnnotationMetadata(AutoConfigurationSorter.java:233)
    at org.springframework.boot.autoconfigure.AutoConfigurationSorter$AutoConfigurationClass.getOrder(AutoConfigurationSorter.java:204)
    at org.springframework.boot.autoconfigure.AutoConfigurationSorter$AutoConfigurationClass.access$000(AutoConfigurationSorter.java:150)
    at org.springframework.boot.autoconfigure.AutoConfigurationSorter.lambda$getInPriorityOrder$0(AutoConfigurationSorter.java:62)
    at java.util.TimSort.countRunAndMakeAscending(TimSort.java:355)
    at java.util.TimSort.sort(TimSort.java:234)
    at java.util.Arrays.sort(Arrays.java:1512)
    at java.util.ArrayList.sort(ArrayList.java:1462)
    at org.springframework.boot.autoconfigure.AutoConfigurationSorter.getInPriorityOrder(AutoConfigurationSorter.java:61)
    at org.springframework.boot.autoconfigure.AutoConfigurationImportSelector$AutoConfigurationGroup.sortAutoConfigurations(AutoConfigurationImportSelector.java:430)
    at org.springframework.boot.autoconfigure.AutoConfigurationImportSelector$AutoConfigurationGroup.selectImports(AutoConfigurationImportSelector.java:415)
    at org.springframework.context.annotation.ConfigurationClassParser$DeferredImportSelectorGrouping.getImports(ConfigurationClassParser.java:878)
    at org.springframework.context.annotation.ConfigurationClassParser$DeferredImportSelectorGroupingHandler.processGroupImports(ConfigurationClassParser.java:801)
    at org.springframework.context.annotation.ConfigurationClassParser$DeferredImportSelectorHandler.process(ConfigurationClassParser.java:771)
    at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:185)
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:315)
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:232)
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:275)
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:95)
    at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:705)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:531)
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:140)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:742)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:389)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:311)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1213)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1202)
    at com.test.server.Application.main(Application.java:45)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49)
Caused by: java.io.FileNotFoundException: class path resource [org/springdoc/core/MultipleOpenApiSupportConfiguration.class] cannot be opened because it does not exist
    at org.springframework.core.io.ClassPathResource.getInputStream(ClassPathResource.java:180)
    at org.springframework.core.type.classreading.SimpleMetadataReader.<init>(SimpleMetadataReader.java:51)
    at org.springframework.core.type.classreading.SimpleMetadataReaderFactory.getMetadataReader(SimpleMetadataReaderFactory.java:103)
    at org.springframework.boot.type.classreading.ConcurrentReferenceCachingMetadataReaderFactory.createMetadataReader(ConcurrentReferenceCachingMetadataReaderFactory.java:86)
    at org.springframework.boot.type.classreading.ConcurrentReferenceCachingMetadataReaderFactory.getMetadataReader(ConcurrentReferenceCachingMetadataReaderFactory.java:73)
    at org.springframework.core.type.classreading.SimpleMetadataReaderFactory.getMetadataReader(SimpleMetadataReaderFactory.java:81)
    at org.springframework.boot.autoconfigure.AutoConfigurationSorter$AutoConfigurationClass.getAnnotationMetadata(AutoConfigurationSorter.java:229)
    ... 32 common frames omitted

The problem is with the incompatible versions of springdoc-openapi-core and springdoc-openapi-ui libraries. I've fixed it by setting 1.1.49 version for both dependencies:

<dependency>
    <groupId>org.springdoc</groupId>
    <artifactId>springdoc-openapi-core</artifactId>
    <version>1.1.49</version>
</dependency>

<dependency>
    <groupId>org.springdoc</groupId>
    <artifactId>springdoc-openapi-ui</artifactId>
    <version>1.1.49</version>
</dependency>