I am using Drools workbench 7.17 integrated with Kie execution server. I have created project using workbench which consists of data models, rule file and global definitions.
I want to use global variable to set some value in it if rule is executed and retrieve global variable value. I can achieve this using spring boot application where we add global variable inside session using kieSession.setGlobal("response", response);
and retrieves it using kieSession.getGlobal("response")
. I tried replicating same with workbench but I am getting null pointer exception when I am trying to set value in global variable. Below is my rule file:
package com.myspace.drools_ruleengine;
import com.myspace.drools_ruleengine.Person;
global com.myspace.drools_ruleengine.Response response;
dialect "mvel"
rule "If person age >= 18 then person is adult"
no-loop
when
$p: Person(age >= 18)
then
response.setMessage("Adult"); // throwing error- null pointer exception
end
I have created global definition and added response as a alias for Response class. Is there anything required apart from this ? I am using Kie Server Rest API to insert facts.
You need to initialize global variable while sending requests for rule execution, like as:
<batch-execution>
<set-global identifier="obj">
<com.sample.Test/>
</set-global>
<insert>
<com.Person>
<name>abc</name>
</com.Person>
</insert>
<fire-all-rules/>
</batch-execution>
Try with this approach