Spring boot : Unable to load cache item: javax/servlet/Filter

Question

I have a spring boot project and getting some error related to javax servlet filter.

Is it some kind of version compatibility or I am missing something in pom file.

Following is the log from the console and the pom file.

I have been searching all over, couldn't find anything.

Exception in thread "main" java.lang.IllegalStateException: Cannot load configuration class: org.springframework.security.oauth2.config.annotation.web.configuration.AuthorizationServerSecurityConfiguration
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.enhanceConfigurationClasses(ConfigurationClassPostProcessor.java:403)
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanFactory(ConfigurationClassPostProcessor.java:249)
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:281)
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:125)
    at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:687)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:525)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:303)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107)
    at com.abc.application.Application.main(Application.java:15)
Caused by: java.lang.IllegalStateException: Unable to load cache item
    at org.springframework.cglib.core.internal.LoadingCache.createEntry(LoadingCache.java:79)
    at org.springframework.cglib.core.internal.LoadingCache.get(LoadingCache.java:34)
    at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData.get(AbstractClassGenerator.java:116)
    at org.springframework.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:291)
    at org.springframework.cglib.proxy.Enhancer.createHelper(Enhancer.java:480)
    at org.springframework.cglib.proxy.Enhancer.createClass(Enhancer.java:337)
    at org.springframework.context.annotation.ConfigurationClassEnhancer.createClass(ConfigurationClassEnhancer.java:138)
    at org.springframework.context.annotation.ConfigurationClassEnhancer.enhance(ConfigurationClassEnhancer.java:110)
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.enhanceConfigurationClasses(ConfigurationClassPostProcessor.java:393)
    ... 11 more
Caused by: java.lang.NoClassDefFoundError: javax/servlet/Filter
    at java.lang.Class.getDeclaredConstructors0(Native Method)
    at java.lang.Class.privateGetDeclaredConstructors(Class.java:2671)
    at java.lang.Class.getDeclaredConstructors(Class.java:2020)
    at org.springframework.cglib.proxy.Enhancer.generateClass(Enhancer.java:566)
    at org.springframework.cglib.transform.TransformingClassGenerator.generateClass(TransformingClassGenerator.java:33)
    at org.springframework.cglib.core.DefaultGeneratorStrategy.generate(DefaultGeneratorStrategy.java:25)
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanFactoryAwareGeneratorStrategy.generate(ConfigurationClassEnhancer.java:252)
    at org.springframework.cglib.core.AbstractClassGenerator.generate(AbstractClassGenerator.java:329)
    at org.springframework.cglib.proxy.Enhancer.generate(Enhancer.java:492)
    at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:93)
    at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:91)
    at org.springframework.cglib.core.internal.LoadingCache$2.call(LoadingCache.java:54)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at org.springframework.cglib.core.internal.LoadingCache.createEntry(LoadingCache.java:61)
    ... 19 more
Caused by: java.lang.ClassNotFoundException: javax.servlet.Filter
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 33 more

Answer 1

For me problem were in pom file (in spring boot 2 project), when I used a parent spring boot in version 2.1.9 which under the hood uses spring-core in version 5.1.10.RELEASE

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.9.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

I had dependency:

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-core</artifactId>
            <version>5.2.0.RELEASE</version>
        </dependency>

removing it resolved problem

Answer 2

I was getting the similar error in my Gradle project(might be a problem with Maven too) when I was trying to upgrade my Spring Boot version to latest one.

A quick gradle clean solved that problem for me.

Answer 3

Usually, this Filter class can be found in embedded tomcat jar. So please make sure that your application (jar) contains this file:

Open up the Jar file of the compiled spring boot application and check whether the jar named like tomcat-embed-core resides in the BOOT-INF\\lib folder.

This answer is valid as long as you're running tomcat of course + use JAR artifact for spring boot application (for WAR the folder is different, probably WEB-INF/lib although I've never worked with WARs of Spring Boot application so I might be wrong here)