org.drools.builder.KnowledgeBuilder Maven / Gradle / Ivy
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/*
* Copyright 2010 Red Hat, Inc. and/or its affiliates.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.drools.builder;
import java.util.Collection;
import org.drools.KnowledgeBase;
import org.drools.definition.KnowledgePackage;
import org.drools.io.Resource;
/**
*
* The KnowledgeBuilder is responsible for taking source files, such as a .drl file, a .bpmn2 file or an .xls file,
* and turning them into a KnowledgePackage of rule and process definitions which a KnowledgeBase
* can consume. It uses the ResourceType enum to tell it the type of the resource it is being asked to build.
*
*
*
*
* The ResourceFactory provides capabilities to load Resources from a number of sources; such as
* Reader, ClassPath, URL, File, ByteArray. Binaries, such as XLS decision tables,
* should not use a Reader based Resource handler, which is only suitable for text based resources.
*
*
*
* It is best practice to always check the hasErrors() method after an addition, you should not add
* more resources or get the KnowledgePackages if there are errors. getKnowledgePackages() will return
* an empty list if there are errors.
*
*
*
* You can create a new KnowledgeBase for all the resources that were added using this builder using
* the newKnowledgeBase() method. This will throw an exception if there are errors for any of the
* resources.
*
*
*
* Simple example showing how to build a KnowledgeBase from an DRL rule resource.
*
*
* KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
* kbuilder.add( ResourceFactory.newUrlResource( "file://myrules.drl" ),
* ResourceType.DRL);
* assertFalse( kbuilder.hasErrors() );
* KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
*
*
*
* Simple example showing how to build a KnowledgeBase from an XLS decision table resource.
*
*
* KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
* DecisionTableConfiguration dtconf = KnowledgeBuilderFactory.newDecisionTableConfiguration();
* dtconf.setInputType( DecisionTableInputType.XLS );
* dtconf.setWorksheetName( "Tables_2" );
* kbuilder.add( ResourceFactory.newUrlResource( "file://IntegrationExampleTest.xls" ),
* ResourceType.DTABLE,
dtconf );
* assertFalse( kbuilder.hasErrors() );
* KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
*
*
*
* Simple example showing how to build a KnowledgeBase from an BPMN2 process resource.
*
*
* KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
* kbuilder.add( ResourceFactory.newUrlResource( "file://myProcess.bpmn2" ),
* ResourceType.BPMN2 );
* KnowledgeBase kbase = kbuilder.newKnowledgeBase();
*
*
* If there are errors a simple toString can print the errors
*
*
* if ( kbuilder.hasErrors() ) {
* log.exception( kbuilder.getErrors().toString() )
* }
*
*
*
* The KnowledgeBuilder can also be built from a configuration using the XML change-set format and
* the ResourceType.CHANGE_SET value. While change-set supports add, remove, and modify as elements.
* KnowledgeBuilder will only process add. If the resource element provided points to a directory, all
* files found in that directory will be added. Currently the knowledge type is not derived from the
* file extension and must be explicitly set in the XML for the resource. It is expected that all
* resources in a directory given resource are of the specified type.
*
*
* <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 http://anonsvn.jboss.org/repos/labs/labs/jbossrules/trunk/drools-api/src/main/resources/change-set-1.0.0.xsd' >
* <add>
* <resource source='http:org/domain/myrules.drl' type='DRL' />
* <resource source='classpath:data/IntegrationExampleTest.xls' type="DTABLE">
* <decisiontable-conf input-type="XLS" worksheet-name="Tables_2" />
* </resource>
* <resource source='file:org/drools/decisiontable/myflow.drf' type='DRF' />
* </add>
* </change-set>
*
*
*
* KnowledgeAgent kagent = KnowledgeAgentFactory.newKnowledgeAgent( "test agent", // the name of the agent
* kaconf );
* kagent.applyChangeSet( ResourceFactory.newUrlResource( url ) ); // resource to the change-set xml for the resources to add
*
*/
public interface KnowledgeBuilder
extends
RuleBuilder,
ProcessBuilder {
/**
* Add a resource of the given ResourceType, using the default resource configuration.
*
* @param resource the Resource to add
* @param type the resource type
*/
void add(Resource resource,
ResourceType type);
/**
* Add a resource of the given ResourceType, using the provided ResourceConfiguration.
* Resources can be created by calling any of the "newX" factory methods of
* ResourceFactory. The kind of resource (DRL, XDRL, DSL,... CHANGE_SET) must be
* indicated by the second argument.
*
* @param resource the Resource to add
* @param type the resource type
* @param configuration the resource configuration
*/
void add(Resource resource,
ResourceType type,
ResourceConfiguration configuration);
/**
* Returns the built packages.
*
* If the KnowledgeBuilder has errors the Collection will be empty. The hasErrors()
* method should always be checked first, to make sure you are getting the packages
* that you wanted built.
*
* @return
* The Collection of KnowledgePackages
*/
Collection getKnowledgePackages();
/**
* Creates a new KnowledgeBase from the knowledge packages that have been added to
* this builder. An exception is thrown if there are any errors.
*/
KnowledgeBase newKnowledgeBase();
/**
* If errors occurred during the build process they are added here
* @return
*/
boolean hasErrors();
/**
* Return errors that occurred during the build process.
* @return
*/
KnowledgeBuilderErrors getErrors();
/**
* Return the knowledge builder results for the listed severities.
*
* @param severities
* @return
*/
KnowledgeBuilderResults getResults(ResultSeverity...severities );
/**
* Checks if the builder generated any results of the listed severities
* @param severities
* @return
*/
boolean hasResults(ResultSeverity...severities );
/**
* Remove the last added Resource.
* Can be useful in case this last addition generated some compilation problem.
* If multiple Resources have been added in batch using a CompositeKnowledgeBuilder,
* it removes all of them.
*/
void undo();
/**
* Return a CompositeKnowledgeBuilder allowing to add multiple Resources
* at the same time, without worrying about cross dependencies among them.
* @return
*/
CompositeKnowledgeBuilder batch();
}