Spring+Drools Integration

Hello,

I have been attempting to work with Drools & Spring and have mostly met with frustration.

On going thru many sources, I could know some info on how to integrate both of them. Well, I have been trying to read the DRL file and display the message available in DRL file.

I have followed using a RuleBaseBeanFactory (mentioned somewhere on internet) and defining my Spring beans in applicationContext XML file. No error message is coming for me on the application UI, but I could notice that I am unable to read the DRL file as it is displaying some null value which I have already set in DRL file. (For your info, I am only using DRL file, and not any RuleFlow or DSL file.)

My code involves a POJO, RuleBaseBeanFactory to read the DRL file, applicationContext XML file, a simple JSP. Very simple.

Can anyone help me out to solve the issue? If I am not clear, let me know. Any sample with Drools and Spring is highly appreciated. [I have gone thru many resources but am unable to get a clear picture on integrating both of them]. Please do the needful.

Thanks,
Mercury

You can use the Spring/JSR-94 integration classes like here.

Hey Guys Please use the following way to integrate Drools in your Spring Framework.

There are two java classes
1) Member.java
--------------------------------------------------------------------------
package com.hp;

public class Member {
private String type;
private int age;
private int fees;

public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public int getFees() {
return fees;
}
public void setFees(int fees) {
this.fees = fees;
}
}
--------------------------------------------------------------------------

2) MemberRulesClient.java
--------------------------------------------------------------------------
package com.hp;

import com.hp.Member;
import org.drools.KnowledgeBase;
import org.drools.KnowledgeBaseFactory;
import org.drools.builder.KnowledgeBuilder;
import org.drools.builder.KnowledgeBuilderFactory;
import org.drools.builder.ResourceType;
import org.drools.io.Resource;
import org.drools.runtime.StatefulKnowledgeSession;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFacto ry;
import org.springframework.core.io.FileSystemResource;

public class MemberRulesClient {
private Resource resourceFile;
private ResourceType resourceType;

public Resource getResourceFile() {
return resourceFile;
}

public void setResourceFile(Resource resourceFile) {
this.resourceFile = resourceFile;
}

public ResourceType getResourceType() {
return resourceType;
}

public void setResourceType(ResourceType resourceType) {
this.resourceType = resourceType;
}

public static final void main(String[] args) {

BeanFactory beanFactory = new XmlBeanFactory(new FileSystemResource(
"src/main/config/bean-config.xml"));
MemberRulesClient client = (MemberRulesClient) beanFactory.getBean("MemberRulesClientBean");
KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
kbuilder.add(client.resourceFile, client.resourceType);
KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
kbase.addKnowledgePackages(kbuilder.getKnowledgePa ckages());
StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession();
Member member = new Member();
member.setType(args[0].toLowerCase());
member.setAge(Integer.parseInt(args[1]));
ksession.insert(member);
ksession.fireAllRules();
System.out.println(" Provider Fess : " + (member.getFees())
+ " For Member Type : " + member.getType() + " having age : "
+ member.getAge());


}
}
--------------------------------------------------------------------------

Corresponding Context Descriptor file for Spring is -->

bean-config.xml
--------------------------------------------------------------------------
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:drools="http://drools.org/schema/drools-spring"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd" >

<bean id="resType" class="org.drools.io.ResourceFactory" factory-method="newClassPathResource">
<constructor-arg index="0" type="java.lang.String" value="MemberRules.drl" />
</bean>

<bean id="resTypeBean" class="org.drools.builder.ResourceType" factory-method="addResourceTypeToRegistry">
<constructor-arg index="0" type="java.lang.String" value="DRL" />
<constructor-arg index="1" type="java.lang.String" value="Drools Rule Language" />
<constructor-arg index="2" type="java.lang.String" value="drl" />
</bean>

<!-- <bean id="MemberRulesClientBean"
class="com.hp.MemberRulesClient">
<property name="resourceFile" ref="resType" />
<property name="resourceType" ref="resTypeBean" />
</bean>
-->

<bean id="MemberRulesClientBean" class="com.hp.MemberRulesClient" autowire="byType">
</bean>

</beans>
--------------------------------------------------------------------------

and the required DRL rule file is -->
MemberRules.drl
--------------------------------------------------------------------------
package com.hp

import com.hp.Member;

rule "Member Type - Bronze"
no-loop
when
m : Member(type == "bronze");
then
if(m.getAge() >=1 && m.getAge() <= 30){
m.setFees(30);
update(m);
}else if(m.getAge() >= 31 && m.getAge() <=59){
m.setFees(25);
update(m);
}else{
m.setFees(20);
update(m);
}
end

rule "Member Type - Silver"
no-loop
when
m : Member(type == "silver");
then
if(m.getAge() >=1 && m.getAge() <= 30){
m.setFees(25);
update(m);
}else if(m.getAge() >= 31 && m.getAge() <=59){
m.setFees(20);
update(m);
}else{
m.setFees(15);
update(m);
}
end

rule "Member Type - Gold"
no-loop
when
m : Member(type == "gold");
then
if(m.getAge() >=1 && m.getAge() <= 30){
m.setFees(20);
update(m);
}else if(m.getAge() >= 31 && m.getAge() <=59){
m.setFees(15);
update(m);
}else{
m.setFees(10);
update(m);
}
end
--------------------------------------------------------------------------
these above mentioned files (bean.xml and DRL file) must be stored in config folder of your project.
This will simply integrate Drools With Spring IOC Framework.

Cheers,
Abhishek Jha