求高手解决一个关于问题org.springframework.beans.factory.BeanCreationException
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in file [C:\Tomcat 6.0\webapps\PCHMonitor\WEB-INF\classes\applicationContext.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: org/hibernate/cfg/AnnotationConfiguration