我的第一个web project 有问题，请高手帮助

Question

严重: Begin event threw exception
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:623)
at org.apache.commons.beanutils.PropertyUtilsBean.invokeMethod(PropertyUtilsBean.java:1773)
at org.apache.commons.beanutils.PropertyUtilsBean.setSimpleProperty(PropertyUtilsBean.java:1759)
at org.apache.commons.beanutils.PropertyUtilsBean.setNestedProperty(PropertyUtilsBean.java:1648)
at org.apache.commons.beanutils.PropertyUtilsBean.setProperty(PropertyUtilsBean.java:1677)
at org.apache.commons.beanutils.BeanUtilsBean.setProperty(BeanUtilsBean.java:1022)
at org.apache.commons.beanutils.BeanUtilsBean.populate(BeanUtilsBean.java:811)
at org.apache.commons.beanutils.BeanUtils.populate(BeanUtils.java:298)
at org.apache.commons.digester.SetPropertiesRule.begin(SetPropertiesRule.java:217)
at org.apache.commons.digester.Rule.begin(Rule.java:152)
at org.apache.commons.digester.Digester.startElement(Digester.java:1286)