Terman Terman - 5 months ago 98
Java Question

org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class

I replaced j2ee.jar with servle-api.com from my tomcat 6.0 installation directory:
And that yields the error below. I'm presently trying to figure out the cause. What might the problem be.

I have a the bean defined in a configuration file: Sempedia-service.xml
as follows


<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-2.5.xsd">
<bean id="sempediaSearchService"
class="com.service.SempediaSearchManager" />


</beans>


my web.xml specifies the following beans:

<context-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/Sempedia-service.xml,/WEB-INF/Sempedia-persistence.xml</param-value>
</context-param>

<listener>
<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>


Stack Trace

SEVERE: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [com.service.SempediaSearchManager] for bean with name 'sempediaSearchService' defined in ServletContext resource [/WEB-INF/Sempedia-service.xml]; nested exception is java.lang.ClassNotFoundException: com.service.SempediaSearchManager
at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1141)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType(AbstractAutowireCapableBeanFactory.java:524)
at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:1177)
at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:758)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:422)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:728)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:380)
at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:255)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:199)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:45)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:3934)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4429)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:722)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
at org.apache.catalina.core.StandardService.start(StandardService.java:516)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)
at org.apache.catalina.startup.Catalina.start(Catalina.java:583)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:288)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:413)
Caused by: java.lang.ClassNotFoundException: com.service.SempediaSearchManager
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1387)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1233)
at org.springframework.util.ClassUtils.forName(ClassUtils.java:211)
at org.springframework.beans.factory.support.AbstractBeanDefinition.resolveBeanClass(AbstractBeanDefinition.java:385)
at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1138)
... 24 more

Answer

The problem is that there is no class called com.service.SempediaSearchManager on your webapp's classpath. The most likely root causes are:

  • the fully qualified classname is incorrect in /WEB-INF/Sempedia-service.xml; i.e. the class name is something else,

  • the class is not in your webapp's /WEB-INF/classes directory tree or a JAR file in the /WEB-INF/lib directory.

EDIT : The only other thing that I can think of is that the ClassDefNotFoundException may actually be a result of an earlier class loading / static initialization problem. Check your log files for the first stack trace, and look the nested exceptions, i.e. the "caused by" chain. [If a class load fails one time and you or Spring call Class.forName() again for some reason, then Java won't actually try to load a second time. Instead you will get a ClassDefNotFoundException stack trace that does not explain the real cause of the original failure.]

If you are still stumped, you should take Eclipse out of the picture. Create the WAR file in the form that you are eventually going to deploy it, then from the command line:

  1. manually shutdown Tomcat

  2. clean out your Tomcat webapp directory,

  3. copy the WAR file into the webapp directory,

  4. start Tomcat.

If that doesn't solve the problem directly, look at the deployed webapp directory on Tomcat to verify that the "missing" class is in the right place.

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