将 Mule 负载对象传递给 Drools 规则

Question

我打算构建一个 mule 流，它从数据库获取数据，构建一个对象，然后触发流口水规则。我的问题是 initialFacts-ref="#[payload.MapObject]" 无法解决。在部署时，我得到 'No bean named '#[[payload.MapObject]' is defined' 如何将有效负载对象作为事实放入规则中？

<?xml version="1.0" encoding="UTF-8"?>
<mule xmlns:dw="http://www.mulesoft.org/schema/mule/ee/dw"             xmlns:metadata="http://www.mulesoft.org/schema/mule/metadata" xmlns:spring="http://www.springframework.org/schema/beans"
xmlns:db="http://www.mulesoft.org/schema/mule/db"
xmlns:json="http://www.mulesoft.org/schema/mule/json"
xmlns:tracking="http://www.mulesoft.org/schema/mule/ee/tracking" 
xmlns:http="http://www.mulesoft.org/schema/mule/http" 
xmlns:vm="http://www.mulesoft.org/schema/mule/vm"
xmlns:jms="http://www.mulesoft.org/schema/mule/jms"
xmlns="http://www.mulesoft.org/schema/mule/core" 
xmlns:doc="http://www.mulesoft.org/schema/mule/documentation"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:bpm="http://www.mulesoft.org/schema/mule/bpm"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-current.xsd
http://www.mulesoft.org/schema/mule/db 
http://www.mulesoft.org/schema/mule/db/current/mule-db.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/vm
http://www.mulesoft.org/schema/mule/vm/current/mule-vm.xsd
http://www.mulesoft.org/schema/mule/jms
http://www.mulesoft.org/schema/mule/jms/current/mule-jms.xsd
http://www.mulesoft.org/schema/mule/core
http://www.mulesoft.org/schema/mule/core/current/mule.xsd
http://www.mulesoft.org/schema/mule/bpm
http://www.mulesoft.org/schema/mule/bpm/3.2/mule-bpm.xsd
http://www.mulesoft.org/schema/mule/http
http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd
http://www.mulesoft.org/schema/mule/ee/tracking
http://www.mulesoft.org/schema/mule/ee/tracking/current/mule-tracking-ee.xsd
http://www.mulesoft.org/schema/mule/ee/dw
http://www.mulesoft.org/schema/mule/ee/dw/current/dw.xsd">

<bpm:drools />

<flow name="myFlow" >
    <http:listener config-ref="HTTP_Listener_Configuration" path="/myflow" doc:name="HTTP">
        <http:response-builder>
            <http:header headerName="Access-Control-Allow-Origin" value="*"/>
        </http:response-builder>
    </http:listener>
    <db:select config-ref="MySQL_Finance" doc:name="Database">
        <db:parameterized-query><![CDATA[SELECT * FROM myTable WHERE ID = #[message.inboundProperties.'http.query.params'.ID]]]></db:parameterized-query>
    </db:select>
    <response>
        <json:object-to-json-transformer doc:name="Object to JSON"/>
    </response>

    <component class="org.mule.transformers.myMapping" doc:name="myMapping"/>

   <bpm:rules doc:name="myRule" rulesDefinition="src/main/resources/rules/myRule.drl" initialFacts-ref="#[payload.MapObject]"/>

</flow>

</mule>

package org.mule.transformers;
import org.mule.api.MuleMessage;
import org.mule.api.transformer.TransformerException;
import org.mule.transformer.AbstractMessageTransformer;

public class myMapping extends AbstractMessageTransformer {

/**
 * @param args
 */

public Object transformMessage(MuleMessage message, String outputEncoding) throws TransformerException {

    Object myMapping = null;

    if(message != null){

        myMapping = message.getPayload();

    }

    return myMapping;

} 
 }

Answer 1

initialFacts-ref 指的是现有的 Spring bean，因此您不能像您尝试的那样使用 MEL 表达式。它用于加载初始事实，因此它是静态的。

在您的情况下，您似乎只想处理规则中的当前消息，而不是向规则引擎提供一组初始事实。在这种情况下，没有什么可做的。当前的消息负载传递给 Drools，因此您可以直接访问它。

将 Mule 负载对象传递给 Drools 规则

Passing a Mule payload object to Drools rule

drools

mule