ClassNotFoundException即使類可用

Question

我的問題是，即使類OrderDAO和​​可用我收到此錯誤，即使一切都運行得很好。我的堆棧跟蹤低於：

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 

我爲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> 

和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

ClassNotFoundException不能扔是否存在類在階級路徑下。這將是肯定的代碼問題。這些可以是原因： -

1）類存在，但是以類路徑/右夾

2）作爲其ClassNotFoundException當應用程序試圖通過字符串名加載類被拋出未展開，所以編譯可以通過，但在運行時會出現問題。所以，可能是查找包是不正確的，但部署在正確的道路

Answer 2

嘗試使用相同的classpath從命令行執行此：

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

如果存在這些類和API的說明，將衝擊片雷管。如果不是，則爲錯誤。