Java 子流调用在SpringWebFlow中不起作用

我正在SpringMVC中创建一个ShoppingCart应用程序

注册流（流id=注册流）

MailSender流（流id=mailFlow）

当用户注册数据成功输入数据库时，将触发邮件发送者流（子流）

我的父流是RegistrationFlow

请查找以下子流调用代码：

<!-- other navigation rules of parent flow -->

<subflow-state id="mailSenderFlow" subflow="mailFlow">
    <input name="userEmail" value="flowScope.regBean.userDTO.userMail"/>
    <transition on="finishMailFlow" to="checkMailFlowResult" />
</subflow-state>

<decision-state id="checkMailFlowResult">
    <if test="mailSender.mailConfirmation(currentEvent.attributes.mailFlowOutcome)"
        then="regSuccess" else="regConfirm" />
</decision-state>

<end-state id="regSuccess" view="/WEB-INF/view/regSuccess.jsp" />

---

有人能解决这个问题吗？

请尝试在您的价值内使用单引号：

<output name="mailFlowOutcome" value="'mail sending done'"/>

谢谢rptmat57。它起作用了。你能解释一下原因吗？是不是输出值没有被视为字符串数据类型？准确地说。如果您只有一个单词（只要它不是保留单词），EL将解析并计算它是字符串。否则，它将尝试解析表达式（不确定具体如何解析），并引发错误

  org.springframework.webflow.execution.FlowExecutionException: Exception  thrown in state 'mailSenderFlow' of flow 'registrationFlow'
  at  org.springframework.webflow.engine.impl.FlowExecutionImpl.wrap(FlowExecutionImpl.java:573)
  at org.springframework.webflow.engine.impl.FlowExecutionImpl.resume(FlowExecutionImpl.java:263)
at org.springframework.webflow.executor.FlowExecutorImpl.resumeExecution(FlowExecutorImpl.java:169)
at org.springframework.webflow.mvc.servlet.FlowHandlerAdapter.handle(FlowHandlerAdapter.java:253)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
Truncated. see log file for complete stacktrace

Caused By: org.springframework.expression.spel.SpelParseException: EL1041E:  After parsing a valid expression, there is still more data in the expression: 'sending'
at org.springframework.expression.spel.standard.InternalSpelExpressionParser.doParseExpression(InternalSpelExpressionParser.java:130)
at org.springframework.expression.spel.standard.SpelExpressionParser.doParseExpression(SpelExpressionParser.java:60)
at org.springframework.expression.spel.standard.SpelExpressionParser.doParseExpression(SpelExpressionParser.java:32)
at org.springframework.expression.common.TemplateAwareExpressionParser.parseExpression(TemplateAwareExpressionParser.java:73)
at org.springframework.binding.expression.spel.SpringELExpressionParser.parseSpelExpression(SpringELExpressionParser.java:96)
Truncated. see log file for complete stacktrace>

<output name="mailFlowOutcome" value="'mail sending done'"/>