[rules-users] Problem when using multiple rule files (Drools 5)

[Olaf Raether]

Now i found my fault !

What i did wrong was writting every single drl -file into seperate pkg -
file 
instead of writing them in one single pkg - file. 

I find my error in reasoning with the follow code (modified hello world
example from drools
project wizzard). Adding the two drl - files result only in ONE pkg - file.

Thanks to everyone !



package com.sample;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.Collection;

import org.drools.KnowledgeBase;
import org.drools.KnowledgeBaseFactory;
import org.drools.builder.KnowledgeBuilder;
import org.drools.builder.KnowledgeBuilderError;
import org.drools.builder.KnowledgeBuilderErrors;
import org.drools.builder.KnowledgeBuilderFactory;
import org.drools.builder.ResourceType;
import org.drools.definition.KnowledgePackage;
import org.drools.io.ResourceFactory;
import org.drools.logger.KnowledgeRuntimeLogger;
import org.drools.logger.KnowledgeRuntimeLoggerFactory;
import org.drools.runtime.StatefulKnowledgeSession;

/**
 * This is a sample class to launch a rule.
 */
public class DroolsTest {

	public static final void main(String[] args) {
		try {
			// load up the knowledge base
			KnowledgeBase kbase = readKnowledgeBase();
			StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession();
			KnowledgeRuntimeLogger logger =
KnowledgeRuntimeLoggerFactory.newFileLogger(ksession, "test");
			// go !
			Message message = new Message();
			message.setMessage("Hello World");
			message.setStatus(Message.HELLO);
			ksession.insert(message);
			ksession.fireAllRules();
			logger.close();
		} catch (Throwable t) {
			t.printStackTrace();
		}
	}

	private static KnowledgeBase readKnowledgeBase() throws Exception {
		KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
		kbuilder.add(ResourceFactory.newClassPathResource("Sample0.drl"),
ResourceType.DRL);
		kbuilder.add(ResourceFactory.newClassPathResource("Sample1.drl"),
ResourceType.DRL);
		KnowledgeBuilderErrors errors = kbuilder.getErrors();
		if (errors.size() > 0) {
			for (KnowledgeBuilderError error: errors) {
				System.err.println(error);
			}
			throw new IllegalArgumentException("Could not parse knowledge.");
		}
		
		// Write pks to file
		Collection<KnowledgePackage>  pks = kbuilder.getKnowledgePackages();
		int i =0;
		for(KnowledgePackage kp : pks) {
		    ObjectOutputStream out = new ObjectOutputStream( new FileOutputStream(
"Sample"+i+".pkg" ) );
		    System.out.println("Write:"+ "Sample"+i+".pkg");
		    out.writeObject( kp );
            out.close();		  
            i++;
		}
		
		// Read them again
		Collection<KnowledgePackage> kpkgs = new ArrayList<KnowledgePackage>();
		for(;i > 0; i--) {		    
		    ObjectInputStream in = new ObjectInputStream(new
FileInputStream("Sample"+(i-1)+".pkg"));
            Object o = in.readObject();
            System.out.println("Read:"+ "Sample"+i+".pkg");
            in.close();
           KnowledgePackage kp = (KnowledgePackage)o;
           kpkgs.add(kp);
		}		
		
		KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();		
		kbase.addKnowledgePackages(kpkgs);
		return kbase;
	}

	public static class Message {
		
		public static final int HELLO = 0;
		public static final int GOODBYE = 1;
		public static final int START = 2;
        public static final int STOP = 3;

		private String message;

		private int status;

		public String getMessage() {
			return this.message;
		}

		public void setMessage(String message) {
			this.message = message;
		}

		public int getStatus() {
			return this.status;
		}

		public void setStatus(int status) {
			this.status = status;
		}
		
	}
}

Sample0.drl
--------------------
package com.sample
 
import com.sample.DroolsTest.Message;
 
rule "Hello World"
	when
		m : Message( status == Message.HELLO, myMessage : message )
	then
		System.out.println( "Hello" ); 
		m.setMessage( "Goodbye cruel world" );
		m.setStatus( Message.GOODBYE );
		update( m );
end

rule "GoodBye"
	when
		m : Message( status == Message.GOODBYE, myMessage : message )
	then
		System.out.println( myMessage );
		m.setMessage("Start");
		m.setStatus( Message.START );
        update( m );
end


Sample1.drl
--------------------------------------------------------------
package com.sample
 
import com.sample.DroolsTest.Message;
 
rule "Start"
	when
		m : Message( status == Message.START, myMessage : message )
	then
		System.out.println( myMessage ); 
		m.setMessage( "Stop" );
		m.setStatus( Message.STOP );
		update( m );
end

rule "Stop"
	when
		m : Message( status == Message.STOP, myMessage : message )
	then
		System.out.println( myMessage );		        
end
-- 
View this message in context: http://www.nabble.com/Problem-when-using-multiple-rule-files-%28Drools-5%29-tp24623347p24706331.html
Sent from the drools - user mailing list archive at Nabble.com.