Mule ESB 无法触发 Choice 'when' 条件

Question

我无法让 Mule ESB 触发选择“何时”条件

我将 Hello World 流转换为接受 JSON 对象（将 JSON 插入到对象节点）并执行 Choice 节点。

但是我无法触发 CHoice 语句的“when”条件；我总是选择 DEFAULT 情况。下面是流程：

<?xml version="1.0" encoding="UTF-8"?>
<mule xmlns:tracking="http://www.mulesoft.org/schema/mule/ee/tracking" xmlns:json="http://www.mulesoft.org/schema/mule/json" version="EE-3.5.0" xmlns="http://www.mulesoft.org/schema/mule/core" xmlns:core="http://www.mulesoft.org/schema/mule/core" xmlns:doc="http://www.mulesoft.org/schema/mule/documentation" xmlns:http="http://www.mulesoft.org/schema/mule/http" xmlns:spring="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.mulesoft.org/schema/mule/http http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-current.xsd
http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd
http://www.mulesoft.org/schema/mule/json http://www.mulesoft.org/schema/mule/json/current/mule-json.xsd
http://www.mulesoft.org/schema/mule/ee/tracking http://www.mulesoft.org/schema/mule/ee/tracking/current/mule-tracking-ee.xsd">
    <json:object-to-json-transformer name="Object_to_JSON" doc:name="Object to JSON"/>
    <flow doc:name="HelloWorldFlow1" name="HelloWorldFlow1">
        <http:inbound-endpoint doc:description="This endpoint receives an HTTP message." doc:name="HTTP" exchange-pattern="request-response" host="localhost" port="8081" contentType="application/json"/>
        <json:json-to-object-transformer doc:name="JSON to Object" />
        <choice doc:name="Choice-Determine-Route" tracking:enable-default-events="true">
            <when expression="#[payload.uid == &quot;\042ABC\042&quot;]">
                <set-payload value="#['When ABC case']" doc:name="Set Payload"/>
            </when>
            <otherwise>
                <set-payload value="#['Default case, payload:  ' + payload + ', payload.get(\047uid\047): ' + payload.get('uid')]" doc:name="Set Payload"/>
            </otherwise>
        </choice>
    </flow>
</mule>

在此流程中，我使用以下条件和 SetPayload（默认情况）语句：

#[payload.uid == "\042ABC\042"]

    ( Note:  I used the \042 (double quote) because JSONPATH expressions will return "ABC" instead of ABC )

#['Default case, payload:  ' + payload + ', payload.get(\047uid\047): ' + payload.get('uid')]

以下是我的输出：

C:\curl>type input2.txt
{ "uid" : "ABC" }

C:\curl>curl -H "Content-Type: application/json" -i -d @input2.txt http://localh
ost:8081

Default case, payload:  {"uid":"ABC"}, payload.get('uid'): "ABC"

如您所见，我没有触发“when”子句。但是，SetPayload 确实将 Payload.get('uid') 输出为“ABC”

所以我用三种不同的“时间”条件重试三次不同的时间：

#[payload.uid == "ABC"]

#[payload.get('uid') == "ABC"]

#[payload.get('uid') == "\042ABC\042"]

但在所有这三种情况下，我得到以下结果：

Default case, payload:  {"uid":"ABC"}, payload.get('uid'): "ABC"

我该如何解决这个问题？

谢谢

Answer 1

试试这个：-

更新：-

<json:json-to-object-transformer returnClass="java.util.HashMap"  doc:name="JSON to Object" />

    <choice doc:name="Choice-Determine-Route" tracking:enable-default-events="true">
                 <when expression="#[message.payload.uid == 'ABC']">
                    <set-payload value="When ABC case" doc:name="Set Payload"/>
                </when>
                <otherwise>
                    <set-payload value="#['Default case, payload:  ' + payload + ', payload.get(\047uid\047): ' + payload.get('uid')]" doc:name="Set Payload"/>
                </otherwise>
            </choice>

Answer 2

在选择之前对 JSON 转换器尝试以下操作

<json:json-to-object-transformer returnClass="java.util.HashMap"  doc:name="JSON to Object" />

在选择时表达式中使用以下内容

<when expression="#[payload.get('UID') == 'ABC']" >

希望这有帮助。