c3p0的jar包已经加载正常，为何还报错说找不到com.mchange.v2.c3p0.ComboPooledDataSource

而且在类中import时时可以找到这个类的。但是在spring+Hibernate配置数据源的时候，启动Tomcat就报错啊！！！

急急急急急急！！！！！

错误信息如下：

org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class [com.mchange.v2.c3p0.ComboPooledDataSource] for bean with name 'dataSource' defined in class path resource [spring/hibernate-config.xml]; nested exception is java.lang.ClassNotFoundException: com.mchange.v2.c3p0.ComboPooledDataSource
 at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1275)
 at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType(AbstractAutowireCapableBeanFactory.java:575)
 at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:1344)
 at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:910)
 at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:607)
 at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932)
 at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479)
 at org.springframework.web.context.ContextLoader.configureAndRefreshWebApplicationContext(ContextLoader.java:389)
 at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:294)
 at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:112)
 at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:4939)
 at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5434)
 at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
 at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:901)
 at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:877)
 at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:633)
 at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:976)
 at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1653)
 at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
 at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
 at java.util.concurrent.FutureTask.run(FutureTask.java:138)
 at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:885)
 at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
 at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.ClassNotFoundException: com.mchange.v2.c3p0.ComboPooledDataSource
 at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1714)
 at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1559)
 at org.springframework.util.ClassUtils.forName(ClassUtils.java:260)
 at org.springframework.beans.factory.support.AbstractBeanDefinition.resolveBeanClass(AbstractBeanDefinition.java:416)
 at org.springframework.beans.factory.support.AbstractBeanFactory.doResolveBeanClass(AbstractBeanFactory.java:1296)
 at org.springframework.beans.factory.support.AbstractBeanFactory.resolveBeanClass(AbstractBeanFactory.java:1267)
 ... 23 more
2013/08/22 11:16:46 org.apache.catalina.core.StandardContext startInternal