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.examples.templates.Cheese;
import org.drools.examples.templates.Person;
/**
* This shows off a very simple rule template where the data provider is a spreadsheet.
* @author Steve
*
*/
public class SimpleRuleTemplateExample {
public static void main(String[] args) throws Exception {
SimpleRuleTemplateExample launcher = new SimpleRuleTemplateExample();
launcher.executeExample();
}
private void executeExample() throws Exception {
//first we compile the spreadsheet with the template
//to create a whole lot of rules.
final ExternalSpreadsheetCompiler converter = new ExternalSpreadsheetCompiler();
//the data we are interested in starts at row 2, column 2 (e.g. B2)
final String drl = converter.compile(getSpreadsheetStream(), getRulesStream(), 2, 2);
//Uncomment to see rules
//System.out.println( drl );
//BUILD RULEBASE
final RuleBase rb = buildRuleBase(drl);
WorkingMemory wm = rb.newStatefulSession();
//now create some test data
wm.insert( new Cheese( "stilton",
42 ) );
wm.insert( new Person( "michael",
"stilton",
42 ) );
final List<String> list = new ArrayList<String>();
wm.setGlobal( "list",
list );
wm.fireAllRules();
System.out.println(list);
}
/** 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("ExampleCheese.xls");
}
private InputStream getRulesStream() {
return this.getClass().getResourceAsStream("Cheese.drt");
}
}