package里元素必须按照一定的顺序排列:
<result-types><interceptors><default-interceptor-ref><default-action-ref><default-class-ref><global-results><global-exception-mappings>-
action*(所有action放到最后)
<result-types><interceptors><default-interceptor-ref><default-action-ref><default-class-ref><global-results><global-exception-mappings>action*(所有action放到最后)