/*
* Copyright 2010 JBoss Inc
*
* 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.examples.decisiontable;
import java.io.IOException;
import java.io.InputStream;
import java.util.Iterator;
import org.drools.KnowledgeBase;
import org.drools.KnowledgeBaseFactory;
import org.drools.builder.KnowledgeBuilder;
import org.drools.builder.KnowledgeBuilderError;
import org.drools.builder.KnowledgeBuilderFactory;
import org.drools.builder.ResourceType;
import org.drools.decisiontable.ExternalSpreadsheetCompiler;
import org.drools.io.ResourceFactory;
import org.drools.io.impl.ByteArrayResource;
import org.drools.runtime.StatefulKnowledgeSession;
/**
* This shows off a rule template where the data provider is a spreadsheet.
* This example uses the same spreadsheet as the Decision table example ({@link PricingRuleDTExample})
* so that you can see the difference between the two.
*
* Note that even though they use the same spreadsheet, this example is just
* concerned with the data cells and does not use any of the Decision Table data.
*/
public class PricingRuleTemplateExample {
public static void main(String[] args) {
PricingRuleTemplateExample launcher = new PricingRuleTemplateExample();
launcher.executeExample();
}
private int executeExample() {
//BUILD THE KBASE
KnowledgeBase kbase = this.buildKBase();
//GET A KSESSION
StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession();
//now create some test data
Driver driver = new Driver();
Policy policy = new Policy();
ksession.insert(driver);
ksession.insert(policy);
ksession.fireAllRules();
System.out.println("BASE PRICE IS: " + policy.getBasePrice());
System.out.println("DISCOUNT IS: " + policy.getDiscountPercent());
ksession.dispose();
return policy.getBasePrice();
}
/**
* Creates a new kbase containing the rules generated from the xls file and
* the templates.
* @return
* @throws IOException
*/
private KnowledgeBase buildKBase() {
//first we compile the decision table into a whole lot of rules.
final ExternalSpreadsheetCompiler converter = new ExternalSpreadsheetCompiler();
String basePricingDRL = null;
String promotionalPricingDRL = null;
try {
//the data we are interested in starts at row 10, column 3
basePricingDRL = converter.compile(getSpreadsheetStream(), getBasePricingRulesStream(), 10, 3);
//the data we are interested in starts at row 30, column 3
promotionalPricingDRL = converter.compile(getSpreadsheetStream(), getPromotionalPricingRulesStream(), 30, 3);
} catch (IOException e) {
throw new IllegalArgumentException("Invalid spreadsheet stream.", e);
}
//compile the drls
KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
kbuilder.add(new ByteArrayResource(basePricingDRL.getBytes()), ResourceType.DRL);
kbuilder.add(new ByteArrayResource(promotionalPricingDRL.getBytes()), ResourceType.DRL);
//compilation errors?
if (kbuilder.hasErrors()) {
System.out.println("Error compiling resources:");
Iterator<KnowledgeBuilderError> errors = kbuilder.getErrors().iterator();
while (errors.hasNext()) {
System.out.println("\t" + errors.next().getMessage());
}
throw new IllegalStateException("Error compiling resources");
}
//Uncomment to see the base pricing rules
//System.out.println(basePricingDRL);
//Uncomment to see the promotional pricing rules
//System.out.println(promotionalPricingDRL);
//BUILD KBASE
KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());
return kbase;
}
private InputStream getSpreadsheetStream() throws IOException {
return ResourceFactory.newClassPathResource("org/drools/examples/decisiontable/ExamplePolicyPricing.xls").getInputStream();
}
private InputStream getBasePricingRulesStream() throws IOException {
return ResourceFactory.newClassPathResource("org/drools/examples/decisiontable/BasePricing.drt").getInputStream();
}
private InputStream getPromotionalPricingRulesStream() throws IOException {
return ResourceFactory.newClassPathResource("org/drools/examples/decisiontable/PromotionalPricing.drt").getInputStream();
}
}