package org.drools.examples;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringReader;
import java.util.ArrayList;
import java.util.List;
import org.drools.RuleBase;
import org.drools.RuleBaseFactory;
import org.drools.WorkingMemory;
import org.drools.compiler.DroolsParserException;
import org.drools.compiler.PackageBuilder;
import org.drools.decisiontable.ExternalSpreadsheetCompiler;
import org.drools.decisiontable.InputType;
import org.drools.examples.decisiontable.Driver;
import org.drools.examples.decisiontable.Policy;
import org.drools.template.parser.DataListener;
import org.drools.template.parser.TemplateDataListener;
/**
* 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.
*
* This example is also using unstable/experimental apis - as it is not using drools-api.
* @author Steve
*
*/
public class PricingRuleTemplateExample {
public static void main(String[] args) throws Exception {
PricingRuleTemplateExample launcher = new PricingRuleTemplateExample();
launcher.executeExample();
}
private int executeExample() throws Exception {
//first we compile the decision table into a whole lot of rules.
final ExternalSpreadsheetCompiler converter = new ExternalSpreadsheetCompiler();
final List<DataListener> listeners = new ArrayList<DataListener>();
TemplateDataListener l1 = new TemplateDataListener(10, 3, getBasePricingRulesStream());
listeners.add(l1);
TemplateDataListener l2 = new TemplateDataListener(30, 3, getPromotionalPricingRulesStream());
listeners.add(l2);
converter.compile(getSpreadsheetStream(), InputType.XLS, listeners);
String baseRules = l1.renderDRL();
//Uncomment to see the base pricing rules
//System.out.println(baseRules);
String promotionalRules = l2.renderDRL();
//Uncomment to see the promotional pricing rules
//System.out.println(promotionalRules);
//BUILD RULEBASE
final RuleBase rb = buildRuleBase(baseRules, promotionalRules);
WorkingMemory wm = rb.newStatefulSession();
//now create some test data
Driver driver = new Driver();
Policy policy = new Policy();
wm.insert(driver);
wm.insert(policy);
wm.fireAllRules();
System.out.println("BASE PRICE IS: " + policy.getBasePrice());
System.out.println("DISCOUNT IS: " + policy.getDiscountPercent( ));
return policy.getBasePrice();
}
/** Build the rule base from the generated DRL */
private RuleBase buildRuleBase(String... drls) throws DroolsParserException, IOException, Exception {
//now we build the rule package and rulebase, as if they are normal rules
PackageBuilder builder = new PackageBuilder();
for ( String drl : drls ) {
builder.addPackageFromDrl( new StringReader( drl ) );
}
//add the package to a rulebase (deploy the rule package).
RuleBase ruleBase = RuleBaseFactory.newRuleBase();
ruleBase.addPackage( builder.getPackage() );
return ruleBase;
}
private InputStream getSpreadsheetStream() {
return this.getClass().getResourceAsStream("ExamplePolicyPricing.xls");
}
private InputStream getBasePricingRulesStream() {
return this.getClass().getResourceAsStream("BasePricing.drt");
}
private InputStream getPromotionalPricingRulesStream() {
return this.getClass().getResourceAsStream("PromotionalPricing.drt");
}
}