http://struts.apache.org/release/2.2.x/struts2-core/apidocs/org/apache/struts2/interceptor/MessageStoreInterceptor.htmlIn the 'STORE' mode, the interceptor will store the ValidationAware action's message / errors and field errors into HTTP session.In the 'RETRIEVE' mode, the interceptor will retrieve the stored action's message / errors and field errors and put them back into the ValidationAware action.In the 'AUTOMATIC' mode, the interceptor will always retrieve the stored action's message / errors and field errors and put them back into the ValidationAware action, and after Action execution, if the Result is an instance of ServletRedirectResult, the action's message / errors and field errors into automatically be stored in the HTTP session..
增加store interceptor保证actionMessage在redirect后不会丢失 -->
<interceptors>
<interceptor-stack name="crudStack">
<interceptor-ref name="store">
<param name="operationMode">AUTOMATIC</param>
</interceptor-ref>
<interceptor-ref name="paramsPrepareParamsStack" />
</interceptor-stack>
</interceptors>