checkoutcallback.java

drools 一个开放源码的规则引擎

package org.drools.examples.petstore;

/*
 * $Id: CheckoutCallback.java,v 1.2 2004/09/17 00:37:57 mproctor Exp $
 * 
 * Copyright 2001-2003 (C) The Werken Company. All Rights Reserved.
 * 
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided that the
 * following conditions are met:
 * 
 * 1. Redistributions of source code must retain copyright statements and
 * notices. Redistributions must also contain a copy of this document.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * 3. The name "drools" must not be used to endorse or promote products derived
 * from this Software without prior written permission of The Werken Company.
 * For written permission, please contact [e-mail].
 * 
 * 4. Products derived from this Software may not be called "drools" nor may
 * "drools" appear in their names without prior written permission of The Werken
 * Company. "drools" is a trademark of The Werken Company.
 * 
 * 5. Due credit should be given to The Werken Company. (http://werken.com/)
 * 
 * THIS SOFTWARE IS PROVIDED BY THE WERKEN COMPANY AND CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE WERKEN COMPANY OR ITS CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *  
 */

import java.util.List;

import javax.swing.JFrame;

import org.drools.FactException;
import org.drools.RuleBase;
import org.drools.WorkingMemory;

/**
 * @author mproctor
 * 
 * This callback is called when the user pressed the checkout button. It is
 * responsible for adding the items to the shopping cart, asserting the shopping
 * cart and then firing all rules.
 * 
 * A reference to the JFrame is also passed so the rules can launch dialog boxes
 * for user interaction. It uses the ApplicationData feature for this.
 *  
 */
public class CheckoutCallback
{
    RuleBase ruleBase;

    public CheckoutCallback(RuleBase ruleBase)
    {
        this.ruleBase = ruleBase;
    }

    /**
     * Populate the cart and assert into working memory Pass Jframe reference
     * for user interaction
     * 
     * @param frame
     * @param items
     * @return cart.toString();
     */
    public String checkout(JFrame frame, List items) throws FactException
    {
        ShoppingCart cart = new ShoppingCart( );

        //Iterate through list and add to cart
        for ( int i = 0; i < items.size( ); i++ )
        {
            cart.addItem( ( CartItem ) items.get( i ) );
        }

        //add the JFrame to the ApplicationData to allow for user interaction
        WorkingMemory workingMemory = ruleBase.newWorkingMemory( );
        workingMemory.setApplicationData( "frame", frame );
        workingMemory.assertObject( cart );
        workingMemory.fireAllRules( );

        //returns the state of the cart
        return cart.toString( );
    }
}