org.springframework.beans.BeanInstantiationException: Could not instantiate bean

2010-11-3 15:23:24 org.apache.catalina.core.StandardContext listenerStart
严重: Exception sending context initialized event to listener instance of class org.springframework.web.context.ContextLoaderListener
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in ServletContext resource [/WEB-INF/applicationContext.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [org.springframework.orm.hibernate3.LocalSessionFactoryBean]: Constructor threw exception; nested exception is java.lang.NoClassDefFoundError: org/dom4j/DocumentException
Caused by: java.lang.NoClassDefFoundError: org/dom4j/DocumentException


是比如，在

<hibernate-configuration>
<session-factory>
	<mapping
		resource="com/myProject/hbm/test.hbm.xml" />
</session-factory>

</hibernate-configuration>

定义了映射test.hbm.xml，但是找不到test.java。
才出现了上面的错误。