package org.drools.builder;
import java.util.Properties;
import org.drools.KnowledgeBase;
import org.drools.ProviderInitializationException;
/**
* This factory is used to build the knowledge base definitions that are held collectively in
* KnowledgePackages. The KnowledgePackage also provides the role of 'namespacing'. An optional
* KnowlegeBuilderConfiguration can be supplied. The KnowledgeBuilderConfiguration is itself
* created from this factory. The KnowledgeBuilderConfiguration allows you to set the ClassLoader to be used
* along with other setting like the default dialect and compiler, as well as many other options.
*
* <pre>
* KnowledgeBuilder kbuilder = KnowlegeBuilderFactory.newKnowledgeBuilder();
* </pre>
*
*/
public class KnowledgeBuilderFactory {
private static volatile KnowledgeBuilderProvider provider;
/**
* Create and return a new KnowledgeBuilder, using the default KnowledgeBuilderConfigurations
* @return
* The KnowledgeBuilder
*/
public static KnowledgeBuilder newKnowledgeBuilder() {
return getKnowledgeBuilderProvider().newKnowledgeBuilder();
}
/**
* Create and return a new KnowledgeBuilder, using he given KnowledgeBuilderConfigurations
* @return
* The KnowledgeBuilder
*/
public static KnowledgeBuilder newKnowledgeBuilder(KnowledgeBuilderConfiguration conf) {
return getKnowledgeBuilderProvider().newKnowledgeBuilder( conf );
}
public static KnowledgeBuilder newKnowledgeBuilder(KnowledgeBase kbase) {
return getKnowledgeBuilderProvider().newKnowledgeBuilder( kbase );
}
public static KnowledgeBuilder newKnowledgeBuilder(KnowledgeBase kbase,
KnowledgeBuilderConfiguration conf) {
return getKnowledgeBuilderProvider().newKnowledgeBuilder( kbase,
conf );
}
/**
* Create a KnowledgeBuilderConfiguration on which properties can be set.
* @return
* The KnowledgeBuilderConfiguration.
*/
public static KnowledgeBuilderConfiguration newKnowledgeBuilderConfiguration() {
return getKnowledgeBuilderProvider().newKnowledgeBuilderConfiguration();
}
/**
* Create a KnowledgeBuilderConfiguration on which properties can be set. Use
* the given properties file and ClassLoader - either of which can be null.
* @return
* The KnowledgeBuilderConfiguration.
*/
public static KnowledgeBuilderConfiguration newKnowledgeBuilderConfiguration(Properties properties,
ClassLoader classLoader) {
return getKnowledgeBuilderProvider().newKnowledgeBuilderConfiguration( properties,
classLoader );
}
/**
* DecisionTable resources require a ResourceConfiguration, that configuration instance is created
* here. Note that if you are passing a Reader, you must use an InputStreamReader so the encoding
* can be determined.
*
* <pre>
* KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
* DecisionTableConfiguration dtconf = KnowledgeBuilderFactory.newDecisionTableConfiguration();
* dtconf.setInputType( DecisionTableInputType.XLS );
* dtconf.setWorksheetName( "Tables_2" );
* kbuilder.add( new URL( "file://IntegrationExampleTest.xls" ),
* ResourceType.DTABLE,
* dtconf );
* assertFalse( kbuilder.hasErrors() );
* KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
* </pre>
*
* @return
*/
public static DecisionTableConfiguration newDecisionTableConfiguration() {
return getKnowledgeBuilderProvider().newDecisionTableConfiguration();
}
private static synchronized void setKnowledgeBuilderProvider(KnowledgeBuilderProvider provider) {
KnowledgeBuilderFactory.provider = provider;
}
private static synchronized KnowledgeBuilderProvider getKnowledgeBuilderProvider() {
if ( provider == null ) {
loadProvider();
}
return provider;
}
private static void loadProvider() {
try {
Class<KnowledgeBuilderProvider> cls = (Class<KnowledgeBuilderProvider>) Class.forName( "org.drools.builder.impl.KnowledgeBuilderProviderImpl" );
setKnowledgeBuilderProvider( cls.newInstance() );
} catch ( Exception e2 ) {
throw new ProviderInitializationException( "Provider org.drools.builder.impl.KnowledgeBuilderProviderImpl could not be set.",
e2 );
}
}
}