Caused by: java.lang.NoClassDefFoundError: org/apache/log4j/Level

Question

I have to upgrade the logging functionality from log4j-1.2.13 to log4j-api-2.23.0.
Earlier i had these below jars in my WebContent\WEB-INF\lib folder

log4j-1.2.13.jar

log4j.jar

So, i have deleted these two jars and have replaced these with log4j-api-2.23.0.jar and log4j-core-2.23.0.jar
But , i got the below error

28-Feb-2024 13:36:09.319 SEVERE [main] org.springframework.web.servlet.FrameworkServlet.initServletBean Context initialization failed
    org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.validation.beanvalidation.LocalValidatorFactoryBean#0': Invocation of init method failed; nested exception is java.lang.NoClassDefFoundError: org/apache/log4j/Level
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1455)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
        at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
        at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
        at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
        at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:585)
        at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:913)
        at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464)
        at org.springframework.web.servlet.FrameworkServlet.configureAndRefreshWebApplicationContext(FrameworkServlet.java:631)
        at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:588)
        at org.springframework.web.servlet.FrameworkServlet.createWebApplicationContext(FrameworkServlet.java:645)
        at org.springframework.web.servlet.FrameworkServlet.initWebApplicationContext(FrameworkServlet.java:508)
        at org.springframework.web.servlet.FrameworkServlet.initServletBean(FrameworkServlet.java:449)
        at org.springframework.web.servlet.HttpServletBean.init(HttpServletBean.java:133)
        at javax.servlet.GenericServlet.init(GenericServlet.java:158)
        at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1164)
        at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1117)
        at org.apache.catalina.core.StandardWrapper.load(StandardWrapper.java:1010)
        at org.apache.catalina.core.StandardContext.loadOnStartup(StandardContext.java:4958)
        at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5265)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
        at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:726)
        at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:698)
        at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:696)
        at org.apache.catalina.startup.HostConfig.deployDescriptor(HostConfig.java:690)
        at org.apache.catalina.startup.HostConfig$DeployDescriptor.run(HostConfig.java:1889)
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
        at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:112)
        at org.apache.catalina.startup.HostConfig.deployDescriptors(HostConfig.java:583)
        at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:473)
        at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1618)
        at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:319)
        at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:123)
        at org.apache.catalina.util.LifecycleBase.setStateInternal(LifecycleBase.java:423)
        at org.apache.catalina.util.LifecycleBase.setState(LifecycleBase.java:366)
        at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:946)
        at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:835)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1396)
        at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1386)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
        at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134)
        at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:919)
        at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:265)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
        at org.apache.catalina.core.StandardService.startInternal(StandardService.java:432)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
        at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:930)
        at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:183)
        at org.apache.catalina.startup.Catalina.start(Catalina.java:772)
        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.apache.catalina.startup.Bootstrap.start(Bootstrap.java:345)
        at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:476)
    Caused by: java.lang.NoClassDefFoundError: org/apache/log4j/Level
        at org.slf4j.LoggerFactory.getSingleton(LoggerFactory.java:189)
        at org.slf4j.LoggerFactory.bind(LoggerFactory.java:112)
        at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:105)
        at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:235)
        at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:208)
        at org.hibernate.validator.util.LoggerFactory.make(LoggerFactory.java:29)
        at org.hibernate.validator.util.Version.<clinit>(Version.java:24)
        at org.hibernate.validator.engine.ConfigurationImpl.<clinit>(ConfigurationImpl.java:59)
        at org.hibernate.validator.HibernateValidator.createGenericConfiguration(HibernateValidator.java:41)
        at javax.validation.Validation$GenericBootstrapImpl.configure(Validation.java:269)
        at org.springframework.validation.beanvalidation.LocalValidatorFactoryBean.afterPropertiesSet(LocalValidatorFactoryBean.java:184)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1514)
        at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1452)
        ... 60 more
    Caused by: java.lang.ClassNotFoundException: org.apache.log4j.Level
        at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1412)
        at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1220)
        ... 73 more

Below are the files modified attached.

Upgraded the log4j.properties with log4j2.xml

In .classpath file also, i have added these two libraries

<classpathentry kind="lib" path="WebContent/WEB-INF/lib/log4j-api-2.23.0.jar"/>
<classpathentry kind="lib" path="WebContent/WEB-INF/lib/log4j-core-2.23.0.jar"/>

In controller, i have added these imports:

import org.apache.logging.log4j.Level;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.LogManager;

Answer 1

Even if you application does not use Log4j 1.x, some of the libraries you use still might use it.

The concrete problem you are experiencing is due to either slf4j-log4j12 or slf4j-reload4j. Both are bindings from SLF4J to Log4j 1.x.

Depending on the version of SLF4J in your classpath, you either need to replace them with log4j-slf4j-impl or log4j-slf4j2-impl.

See this question for a longer explanation of the difference between the 4 libraries.