The Drools example project contains code snippets that yield warnings: while I absolutely understand that resources are limited and examples might not be the priority and the core code of the engine is of good quality, I do think it is important to display dedication to high quality products.

Having an example project full of code quality issues just gives a very bad first impression of the whole Drools project...

Examples:

public class CashFlowMain {

    public static void main(String[] args) throws Exception {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");

yields WARNING: The value of the local variable sdf is not used

    /**
     * Nice printout of the grid.
     */
    public void dumpGrid() {
        Formatter fmt = new Formatter(System.out);

yields WARNING: Resource leak: 'fmt' is never closed

import java.awt.*;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.font.FontRenderContext;
import java.awt.font.TextLayout;
import java.awt.image.BufferedImage;

import javax.swing.*;

import org.drools.games.GameConfiguration;
import org.drools.games.GameUI;
import org.kie.api.runtime.KieSession;
import org.kie.internal.runtime.StatefulKnowledgeSession;
import org.kie.api.runtime.rule.FactHandle;
import org.kie.api.runtime.rule.EntryPoint;

public class PongUI extends GameUI {

yields WARNING: The import java.awt.event.KeyEvent is never used
WARNING: The import java.awt.event.KeyListener is never used
WARNING: The import java.awt.event.MouseEvent is never used
WARNING: The import java.awt.event.MouseListener is never used
WARNING: The import java.awt.image.BufferedImage is never used
WARNING: The import javax.swing.* is never used
WARNING: The import org.kie.internal.runtime.StatefulKnowledgeSession is never used
WARNING: The import org.kie.api.runtime.rule.FactHandle is never used
WARNING: The import org.kie.api.runtime.rule.EntryPoint is never used

etc