spring webflow中的_eventId无效

Question

有什么方法可以处理 spring webflow 中不存在的 eventIds 或缺少 eventId 参数？

例如对于这个网络流

<flow xmlns="http://www.springframework.org/schema/webflow" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/webflow http://www.springframework.org/schema/webflow/spring-webflow-2.0.xsd">
    <view-state id="welcome">
        <transition on="goForward" to="nextStep"/>
    </view-state>
    <view-state id="nextStep">
        <transition on="endFlow" to="finishStep" />
    </view-state>
    <end-state id="finishStep"/>    
    <global-transitions>
        <transition on="cancel" to="finishStep"/>
    </global-transitions>
</flow>

如何处理带有_eventId=unexistingAction 等参数的请求或没有_eventId 参数的请求？ 这通常会产生一个带有堆栈跟踪的页面...

no transition found on occurence of event in state of flow...

Answer 1

这是处理不存在的转换的方法：

<global-transitions>
    <transition on-exception="org.springframework.webflow.engine.NoMatchingTransitionException" to="handlingViewState">
        <evaluate expression="handlingBean.handle(flowExecutionException)"></evaluate>
    </transition>
</global-transitions>