ClassNotFoundException even when the class is available

Question

My issue is even when class OrderDAO and OrderDAOIml is available I'm getting this error, even though everything was running just fine. My stacktrace is below :

   SEVERE: StandardWrapper.Throwable
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping': Initialization of bean failed; nested exception is org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [com.exclusively.oms.dao.OrderDAOIml] for bean with name 'dataDao' defined in ServletContext resource [/WEB-INF/spring-servlet.xml]; nested exception is java.lang.ClassNotFoundException: com.exclusively.oms.dao.OrderDAOIml
Related cause: org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [com.exclusively.oms.dao.OrderDAOIml] for bean with name 'dataDao' defined in ServletContext resource [/WEB-INF/spring-servlet.xml]; nested exception is java.lang.ClassNotFoundException: com.exclusively.oms.dao.OrderDAOIml
Related cause: org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [com.exclusively.oms.service.OrderServiceIml] for bean with name 'dataServices' defined in ServletContext resource [/WEB-INF/spring-servlet.xml]; nested exception is java.lang.ClassNotFoundException: com.exclusively.oms.service.OrderServiceIml
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:547)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:476)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:303)

    ... 32 more
Caused by: java.lang.ClassNotFoundException: com.exclusively.oms.dao.OrderDAOIml
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1702)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1547)
    at org.springframework.util.ClassUtils.forName(ClassUtils.java:249)
    at org.springframework.beans.factory.support.AbstractBeanDefinition.resolveBeanClass(AbstractBeanDefinition.java:395)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doResolveBeanClass(AbstractBeanFactory.java:1349)
    at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1320)
    ... 49 more
Related cause:
org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [com.exclusively.oms.dao.OrderDAOIml] for bean with name 'dataDao' defined in ServletContext resource [/WEB-INF/spring-servlet.xml]; nested exception is java.lang.ClassNotFoundException: com.exclusively.oms.dao.OrderDAOIml
    at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1328)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.determineTargetType(AbstractAutowireCapableBeanFactory.java:622)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType(AbstractAutowireCapableBeanFactory.java:591)
    at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:1397)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doGetBeanNamesForType(DefaultListableBeanFactory.java:434)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanNamesForType(DefaultListableBeanFactory.java:404)

Caused by: java.lang.ClassNotFoundException: com.exclusively.oms.dao.OrderDAOIml
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1702)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1547)
    at org.springframework.util.ClassUtils.forName(ClassUtils.java:249)
    at org.springframework.beans.factory.support.AbstractBeanDefinition.resolveBeanClass(AbstractBeanDefinition.java:395)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doResolveBeanClass(AbstractBeanFactory.java:1349)
    at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1320)
    ... 51 more
Related cause:
org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [com.exclusively.oms.service.OrderServiceIml] for bean with name 'dataServices' defined in ServletContext resource [/WEB-INF/spring-servlet.xml]; nested exception is java.lang.ClassNotFoundException: com.exclusively.oms.service.OrderServiceIml
    at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1328)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.determineTargetType(AbstractAutowireCapableBeanFactory.java:622)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType(AbstractAutowireCapableBeanFactory.java:591)
    at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:1397)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doGetBeanNamesForType(DefaultListableBeanFactory.java:434)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanNamesForType(DefaultListableBeanFactory.java:404)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:519)
    at org.springframework.context.support.AbstractApplicationContext.getBeansOfType(AbstractApplicationContext.java:1060)
    at org.springframework.beans.factory.BeanFactoryUtils.beansOfTypeIncludingAncestors(BeanFactoryUtils.java:276)
    at org.springframework.web.servlet.handler.AbstractHandlerMapping.detectMappedInterceptors(AbstractHandlerMapping.java:221)
    at org.springframework.web.servlet.handler.AbstractHandlerMapping.initApplicationContext(AbstractHandlerMapping.java:196)
    at org.springframework.web.servlet.handler.AbstractDetectingUrlHandlerMapping.initApplicationContext
    ... 51 more

Oct 12, 2015 3:38:28 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Allocate exception for servlet spring
java.lang.ClassNotFoundException: com.exclusively.oms.dao.OrderDAOIml
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1702)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1547)
    at org.springframework.util.ClassUtils.forName(ClassUtils.java:249)
    at org.springframework.beans.factory.support.AbstractBeanDefinition.resolveBeanClass(AbstractBeanDefinition.java:395)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doResolveBeanClass(AbstractBeanFactory.java:1349)
    at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1320)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.determineTargetType(AbstractAutowireCapableBeanFactory.java:622)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType

My spring-servlet.xml:

<?xml version="1.0" encoding="UTF-8"?>  
<beans xmlns="http://www.springframework.org/schema/beans"  
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
       xmlns:context="http://www.springframework.org/schema/context"  
       xmlns:util="http://www.springframework.org/schema/util" 
       xmlns:tx="http://www.springframework.org/schema/tx"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd  
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd  
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-3.2.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.1.xsd">

<context:annotation-config />

<mvc:default-servlet-handler />

<context:component-scan base-package="com.exclusively.oms" />  

<mvc:annotation-driven />  

<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">  
<property name="driverClassName" value="com.mysql.jdbc.Driver" />  
<property name="url" value="jdbc:mysql://localhost:3306/employee_db" />  
<property name="username" value="root" />  
<property name="password" value="root" />  
</bean>  

<bean id="sessionFactory"  
class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">  
<property name="dataSource" ref="dataSource" />  
<property name="annotatedClasses">  
<list>  
<value>com.exclusively.oms.entity.Order</value>  
</list>  
</property>
<property name="hibernateProperties">  
<props>  
<prop key="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</prop>  
<prop key="hibernate.show_sql">${hibernate.show_sql}</prop>  
</props>  
</property>  
</bean>  

<bean id="txManager"  
class="org.springframework.orm.hibernate4.HibernateTransactionManager">  
<property name="sessionFactory" ref="sessionFactory" />  
</bean>  


<bean id="persistenceExceptionTranslationPostProcessor"  
class="org.springframework.dao.annotation.PersistenceExceptionTranslationPostProcessor" />

<bean id="dataDao" class="com.exclusively.oms.dao.OrderDAOIml"></bean>  
<bean id="dataServices" class="com.exclusively.oms.service.OrderServiceIml"></bean>  

<tx:annotation-driven transaction-manager="txManager" />

</beans>

And web.xml:

 <!DOCTYPE web-app PUBLIC  "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"  "http://java.sun.com/dtd/web-app_2_3.dtd" >

 <web-app>
 <display-name>Archetype Created Web Application</display-name>

 <servlet>
    <servlet-name>spring</servlet-name>
        <servlet-class>
            org.springframework.web.servlet.DispatcherServlet
        </servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
    <servlet-name>spring</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>

Answer 1

Try to execute this from commandline using the same classpath:

javap com.exclusively.oms.dao.OrderDAOIml
javap com.exclusively.oms.service.OrderServiceIml

If those classes exist, a description of their APIs would apper. In case not, an error.

Answer 2

ClassNotFoundException can not be thrown if class exists under class path. It willbe for sure code issue. These can be the reasons :-

1) Class exists but not deployed under classpath/right folder

2) As its ClassNotFoundException which is thrown when an application tries to load in a class through its string name, so compilation can pass but it will be a issue at run time. So may be look up package is not correct but deployed at right path