ools-api.5.0.0.M5.source-code.overview.html Maven / Gradle / Ivy
Drools the Business Logic Integration Platform provides an knowledge centric api, where rules and processes are first class citizens.
The most common interfaces you will use are:
- org.drools.builder.KnowledgeBuilder
- org.drools.KnowledgeBase
- org.drools.agent.KnowledgeAgent
- org.drools.runtime.StatefulKnowledgeSession
- org.drools.runtime.StatelessKnowledgeSession
Factory classes, with static methods, provide instances of the above interfaces. A pluggable provider approach is used to allow provider implementations to
be wired up to the factories at runtime. The Factories you will most commonly used are:
- org.drools.builder.KnowledgeBuilderFactory
- org.drools.io.ResourceFactory
- org.drools.KnowledgeBaseFactory
- org.drools.agent.KnowledgeAgentFactory
A Typical example to load a rule resource.
KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
kbuilder.add( ResourceFactory.newUrlResource( url ),
ResourceType.DRL );
if ( kbuilder.hasErrors() ) {
System.err.println( builder.getErrors().toString() );
}
KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
kbase.addKnowledgePackages( builder.getKnowledgePackages() );
StatefulKnowledgeSession ksession = knowledgeBase.newStatefulKnowledgeSession();
ksession.insert( new Fibonacci( 10 ) );
ksession.fireAllRules();
ksession.dispose();
A Typical example to load a process resource. Notice the ResourceType is changed, in accordance with the Resource type.
KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
kbuilder.add( ResourceFactory.newUrlResource( url ),
ResourceType.DRF );
if ( kbuilder.hasErrors() ) {
System.err.println( builder.getErrors().toString() );
}
KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
kbase.addKnowledgePackages( builder.getKnowledgePackages() );
StatefulKnowledgeSession ksession = knowledgeBase.newStatefulKnowledgeSession();
ksession.startProcess( "Buy Order Process" );
ksession.dispose();
'kbuilder', 'kbase', 'ksession' are the variable identifiers often used, the k prefix is for 'knowledge'.
It is also possible to configure a KnowledgeBase using configuration, via a xml change set, instead of programmatically. Here is a simple change set:
<change-set xmlns='http://drools.org/drools-5.0/change-set'
xmlns:xs='http://www.w3.org/2001/XMLSchema-instance'
xs:schemaLocation='http://drools.org/drools-5.0/change-set change-set-5.0.xsd' >
<add>
<resource source='classpath:org/domain/someRules.drl' type='DRL' />
<resource source='classpath:org/domain/aFlow.drf' type='DRF' />
</add>
</change-set>
And it is added just like any other ResourceType
KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
kbuilder.add( ResourceFactory.newUrlResource( url ),
ResourceType.ChangeSet );
The majority of Drools API is considered stable and should not change, experimental classes and apis will be marked as such.