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<a class="moz-txt-link-freetext" href="http://blog.athico.com/2009/10/spring-integration-for-drools-has.html">http://blog.athico.com/2009/10/spring-integration-for-drools-has.html</a><br>
<br>
<h3 class="post-title"><a
href="http://blog.athico.com/2009/10/spring-integration-for-drools-has.html">Spring
integration for Drools has landed.</a>
</h3>
<div class="post-header-line-1"><span class="post-author">
Posted by
Mark Proctor
</span></div>
<p>I've just committed the first end to end working Spring integration
for Drools. There is still lots more to do, but it at least now allows
for end to end working examples. The latest build that includes this
work can be found from hudson here:<br>
<a
href="https://hudson.jboss.org/hudson/job/drools/lastSuccessfulBuild/artifact/trunk/target/">https://hudson.jboss.org/hudson/job/drools/lastSuccessfulBuild/artifact/trunk/target/</a><br>
<br>
So how does it work. Lets look at the unit test for more details. The <a
href="http://fisheye.jboss.org/browse/JBossRules/trunk/drools-container/drools-spring/src/test/resources/org/drools/container/spring/beans.xml?r=29780">beans.xml</a>
provides a configuration for KnowledgeBases, StatefulKnowledgeSession,
StatelessKnowledgeSession and the ServiceManager. KnowledgeBases can be
confired from a list of resources, that work in the same way that
changeset xml does. This allows resources to be pulled from any URL
resolveble location, be it classpath, localdisk or from artifacts
published from Guvnor:</p>
<pre><drools:kbase id="kbase1">
<drools:resource source="classpath:org/drools/container/spring/testSpring.drl" type="DRL"/>
<drools:resource source="classpath:org/drools/container/spring/IntegrationExampleTest.xls" type="DTABLE">
<drools:decisiontable-conf input-type="XLS" worksheet-name="Tables_2"/>
</drools:resource>
</drools:kbase></pre>
The
above xml shows a KnowledgeBase configured from a DRL and a XLS,
remember we could have added DRFs if we wanted workflow in there too.<br>
<br>
That
KnowledgeBase is now a bean that can be referenced via the id "kbase1".
>From that bean we can now create sessions. The "type" attribute
specifies whether the session is stateful or stateless:
<pre><drools:ksession id="ksession1" type="stateless" kbase="kbase1"/>
<drools:ksession id="ksession2" type="stateful" kbase="kbase1"/></pre>
<br>
Those
sessions are now beans and can be injected into your own classes using
Spring annotations, or used to configure up a Drools ServiceManager.
<pre><drools:serviceManager id="sm1">
<drools:register name="stateless1" ref="ksession1"/>
<drools:register ref="ksession2"/>
</drools:serviceManager></pre>
The
ServiceManager is a new class that I haven't mentioned before that will
be in the upcoming Drools 5.1. The ServiceManager can be worked with
both locally and remotely. It allows sessions to be created and
registered all seamlessly, whether it's local or remote and those
sessions are also exposed both locally and remotely. This ties in with
the <a href="http://camel.apache.org/">Camel </a>work we are doing to
make it easy to work with Drools out of the box in a service and
remoting environment and should hopefully provide the ultimate in event
driven architectures. I'll blog more on those pieces as they fall into
place.<br>
<br>
The XSD can be found here: <a
href="http://fisheye.jboss.org/browse/JBossRules/trunk/drools-container/drools-spring/src/main/resources/drools-spring.xsd?r=29780">spring-drools.xsd</a><br>
<br>
Once the xml is in place, using it with Spring is a doddle and you can
look at the <a
href="http://fisheye.jboss.org/browse/JBossRules/trunk/drools-container/drools-spring/src/test/java/org/drools/container/spring/SpringDroolsTest.java?r=29780">two
unit tests</a> to see this in action:
<pre> public void test1() throws Exception {
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext( "org/drools/container/spring/beans.xml" );
List list = new ArrayList();
StatelessKnowledgeSession kstateless = (StatelessKnowledgeSession) context.getBean( "ksession1" );
kstateless.setGlobal( "list", list );
kstateless.execute( new Person( "Darth", "Cheddar", 50 ) );
assertEquals( 2, list.size() );
list = new ArrayList();
StatefulKnowledgeSession kstateful = (StatefulKnowledgeSession) ((StatefulKnowledgeSession) context.getBean( "ksession2" ));
kstateful.setGlobal( "list", list );
kstateful.insert( new Person( "Darth", "Cheddar", 50 ) );
kstateful.fireAllRules();
assertEquals( 2, list.size() );
}
public void test2() {
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext( "org/drools/container/spring/beans.xml" );
ServiceManager sm = (ServiceManager) context.getBean( "sm1" );
List list = new ArrayList();
StatelessKnowledgeSession kstateless = (StatelessKnowledgeSession) sm.lookup( "stateless1" );
kstateless.setGlobal( "list", list );
kstateless.execute( new Person( "Darth", "Cheddar", 50 ) );
assertEquals( 2, list.size() );
list = new ArrayList();
StatefulKnowledgeSession kstateful = (StatefulKnowledgeSession) sm.lookup( "ksession2" );
kstateful.setGlobal( "list" list );
kstateful.insert( new Person( "Darth", "Cheddar", 50 ) );
kstateful.fireAllRules();
assertEquals( 2, list.size() );
}</pre>
There is still lots more to do, especially around exposing actual
configuration information (JPA etc) and initial setup data (globals,
inserted facts) along with extending this to work with Camel. So if you
want to help, you know where to find us :)<br>
<a href="http://labs.jboss.org/drools/irc.html">IRC</a><br>
<a href="http://labs.jboss.org/drools/lists.html">Mailing Lists</a><br>
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