Question

我需要从配置文件中读取值，并且我一直遇到嵌入式MEL语句的问题;追逐多个死胡同，我没有想法。我使用会话变量将其简化为一个相当简单的示例。

谢谢你，
- 唐

以下代码失败：
消息：[错误：缺少左侧节点]
[近：{... message.payload.contains（＃[sessionVars [＆＃39; valueToMatch＆＃39;]]）....}]

    <set-session-variable variableName="valueToMatch" value="Now we are engaged in a great civil war" />        
    <choice doc:name="Choice">
        <when expression="#[message.payload.contains(#[sessionVars['valueToMatch']])]">
            <set-session-variable variableName="success" value="true" />        
        </when>
        <otherwise>
            <set-session-variable variableName="success" value="false" />       
        </otherwise>
    </choice>

以下代码有效：

    <choice doc:name="Choice">
        <when expression="#[message.payload.contains('Now we are engaged in a great civil war')]">
            <set-session-variable variableName="success" value="true" />        
        </when>
        <otherwise>
            <set-session-variable variableName="success" value="false" />       
        </otherwise>
    </choice>

Answer 1

我的猜测是问题是你要在表达式中放置一个表达式，试试这个：

"#[message.payload.contains(sessionVars['valueToMatch'])]"

而不是

"#[message.payload.contains(#[sessionVars['valueToMatch']])]"

Answer 2

试试这个#[message.payload contains valueToMatch] ...它将完美而简单地工作： -

<set-session-variable variableName="valueToMatch" value="Now we are engaged in a great civil war" />        
    <choice doc:name="Choice">
        <when expression="#[message.payload contains valueToMatch]">
            <set-session-variable variableName="success" value="true" />        
        </when>
        <otherwise>
            <set-session-variable variableName="success" value="false" />       
        </otherwise>
    </choice>

复合MEL语句有问题

2 个答案: