/*
* Copyright 2010 JBoss Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.drools.examples.petstore;
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Vector;
import javax.swing.AbstractButton;
import javax.swing.BorderFactory;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JTable;
import javax.swing.JTextArea;
import javax.swing.ListSelectionModel;
import javax.swing.ScrollPaneConstants;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.TableColumnModel;
import org.drools.KnowledgeBase;
import org.drools.KnowledgeBaseFactory;
import org.drools.builder.KnowledgeBuilder;
import org.drools.builder.KnowledgeBuilderConfiguration;
import org.drools.builder.KnowledgeBuilderFactory;
import org.drools.builder.ResourceType;
import org.drools.io.ResourceFactory;
import org.drools.runtime.StatefulKnowledgeSession;
public class PetStoreExample {
public static void main(String[] args) {
new PetStoreExample().init(true);
}
public PetStoreExample() {
}
public void init(boolean exitOnClose) {
KnowledgeBuilderConfiguration conf = KnowledgeBuilderFactory.newKnowledgeBuilderConfiguration();
KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(conf);
kbuilder.add( ResourceFactory.newClassPathResource( "PetStore.drl",
PetStoreExample.class ),
ResourceType.DRL );
KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
kbase.addKnowledgePackages( kbuilder.getKnowledgePackages() );
//RuleB
Vector<Product> stock = new Vector<Product>();
stock.add( new Product( "Gold Fish",
5 ) );
stock.add( new Product( "Fish Tank",
25 ) );
stock.add( new Product( "Fish Food",
2 ) );
//The callback is responsible for populating working memory and
// fireing all rules
PetStoreUI ui = new PetStoreUI( stock,
new CheckoutCallback( kbase ) );
ui.createAndShowGUI(exitOnClose);
}
/**
* This swing UI is used to create a simple shopping cart to allow a user to add
* and remove items from a shopping cart before doign a checkout upon doing a
* checkout a callback is used to allow drools interaction with the shopping
* cart ui.
*/
public static class PetStoreUI extends JPanel {
private static final long serialVersionUID = 510l;
private JTextArea output;
private TableModel tableModel;
private CheckoutCallback callback;
/**
* Build UI using specified items and using the given callback to pass the
* items and jframe reference to the drools application
*
* @param listData
* @param callback
*/
public PetStoreUI(Vector<Product> items,
CheckoutCallback callback) {
super( new BorderLayout() );
this.callback = callback;
//Create main vertical split panel
JSplitPane splitPane = new JSplitPane( JSplitPane.VERTICAL_SPLIT );
add( splitPane,
BorderLayout.CENTER );
//create top half of split panel and add to parent
JPanel topHalf = new JPanel();
topHalf.setLayout( new BoxLayout( topHalf,
BoxLayout.X_AXIS ) );
topHalf.setBorder( BorderFactory.createEmptyBorder( 5,
5,
0,
5 ) );
topHalf.setMinimumSize( new Dimension( 400,
50 ) );
topHalf.setPreferredSize( new Dimension( 450,
250 ) );
splitPane.add( topHalf );
//create bottom top half of split panel and add to parent
JPanel bottomHalf = new JPanel( new BorderLayout() );
bottomHalf.setMinimumSize( new Dimension( 400,
50 ) );
bottomHalf.setPreferredSize( new Dimension( 450,
300 ) );
splitPane.add( bottomHalf );
//Container that list container that shows available store items
JPanel listContainer = new JPanel( new GridLayout( 1,
1 ) );
listContainer.setBorder( BorderFactory.createTitledBorder( "List" ) );
topHalf.add( listContainer );
//Create JList for items, add to scroll pane and then add to parent
// container
JList list = new JList( items );
ListSelectionModel listSelectionModel = list.getSelectionModel();
listSelectionModel.setSelectionMode( ListSelectionModel.SINGLE_SELECTION );
//handler adds item to shopping cart
list.addMouseListener( new ListSelectionHandler() );
JScrollPane listPane = new JScrollPane( list );
listContainer.add( listPane );
JPanel tableContainer = new JPanel( new GridLayout( 1,
1 ) );
tableContainer.setBorder( BorderFactory.createTitledBorder( "Table" ) );
topHalf.add( tableContainer );
//Container that displays table showing items in cart
tableModel = new TableModel();
JTable table = new JTable( tableModel );
//handler removes item to shopping cart
table.addMouseListener( new TableSelectionHandler() );
ListSelectionModel tableSelectionModel = table.getSelectionModel();
tableSelectionModel.setSelectionMode( ListSelectionModel.SINGLE_SELECTION );
TableColumnModel tableColumnModel = table.getColumnModel();
//notice we have a custom renderer for each column as both columns
// point to the same underlying object
tableColumnModel.getColumn( 0 ).setCellRenderer( new NameRenderer() );
tableColumnModel.getColumn( 1 ).setCellRenderer( new PriceRenderer() );
tableColumnModel.getColumn( 1 ).setMaxWidth( 50 );
JScrollPane tablePane = new JScrollPane( table );
tablePane.setPreferredSize( new Dimension( 150,
100 ) );
tableContainer.add( tablePane );
//Create panel for checkout button and add to bottomHalf parent
JPanel checkoutPane = new JPanel();
JButton button = new JButton( "Checkout" );
button.setVerticalTextPosition( AbstractButton.CENTER );
button.setHorizontalTextPosition( AbstractButton.LEADING );
//attach handler to assert items into working memory
button.addMouseListener( new CheckoutButtonHandler() );
button.setActionCommand( "checkout" );
checkoutPane.add( button );
bottomHalf.add( checkoutPane,
BorderLayout.NORTH );
button = new JButton( "Reset" );
button.setVerticalTextPosition( AbstractButton.CENTER );
button.setHorizontalTextPosition( AbstractButton.TRAILING );
//attach handler to assert items into working memory
button.addMouseListener( new ResetButtonHandler() );
button.setActionCommand( "reset" );
checkoutPane.add( button );
bottomHalf.add( checkoutPane,
BorderLayout.NORTH );
//Create output area, imbed in scroll area an add to bottomHalf parent
//Scope is at instance level so it can be easily referenced from other
// methods
output = new JTextArea( 1,
10 );
output.setEditable( false );
JScrollPane outputPane = new JScrollPane( output,
ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,
ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED );
bottomHalf.add( outputPane,
BorderLayout.CENTER );
this.callback.setOutput( this.output );
}
/**
* Create and show the GUI
*/
public void createAndShowGUI(boolean exitOnClose) {
//Create and set up the window.
JFrame frame = new JFrame( "Pet Store Demo" );
frame.setDefaultCloseOperation(exitOnClose ? JFrame.EXIT_ON_CLOSE : JFrame.DISPOSE_ON_CLOSE);
setOpaque( true );
frame.setContentPane( this );
//Display the window.
frame.pack();
frame.setLocationRelativeTo(null); // Center in screen
frame.setVisible( true );
}
/**
* Adds the selected item to the table
*/
private class ListSelectionHandler extends MouseAdapter {
public void mouseReleased(MouseEvent e) {
JList jlist = (JList) e.getSource();
tableModel.addItem( (Product) jlist.getSelectedValue() );
}
}
/**
* Removes the selected item from the table
*/
private class TableSelectionHandler extends MouseAdapter {
public void mouseReleased(MouseEvent e) {
JTable jtable = (JTable) e.getSource();
TableModel tableModel = (TableModel) jtable.getModel();
tableModel.removeItem( jtable.getSelectedRow() );
}
}
/**
* Calls the referenced callback, passing a the jrame and selected items.
*/
private class CheckoutButtonHandler extends MouseAdapter {
public void mouseReleased(MouseEvent e) {
JButton button = (JButton) e.getComponent();
callback.checkout( (JFrame) button.getTopLevelAncestor(),
tableModel.getItems() );
}
}
/**
* Resets the shopping cart, allowing the user to begin again.
*/
private class ResetButtonHandler extends MouseAdapter {
public void mouseReleased(MouseEvent e) {
output.setText( null );
tableModel.clear();
System.out.println( "------ Reset ------" );
}
}
/**
* Used to render the name column in the table
*/
private class NameRenderer extends DefaultTableCellRenderer {
private static final long serialVersionUID = 510l;
public NameRenderer() {
super();
}
public void setValue(Object object) {
Product item = (Product) object;
setText( item.getName() );
}
}
/**
* Used to render the price column in the table
*/
private class PriceRenderer extends DefaultTableCellRenderer {
private static final long serialVersionUID = 510l;
public PriceRenderer() {
super();
}
public void setValue(Object object) {
Product item = (Product) object;
setText( Double.toString( item.getPrice() ) );
}
}
}
/**
* This is the table model used to represent the users shopping cart While
* we have two colums, both columns point to the same object. We user a
* different renderer to display the different information abou the object -
* name and price.
*/
private static class TableModel extends AbstractTableModel {
private static final long serialVersionUID = 510l;
private String[] columnNames = {"Name", "Price"};
private ArrayList<Product> items;
public TableModel() {
super();
items = new ArrayList<Product>();
}
public int getColumnCount() {
return columnNames.length;
}
public int getRowCount() {
return items.size();
}
public String getColumnName(int col) {
return columnNames[col];
}
public Object getValueAt(int row,
int col) {
return items.get( row );
}
public Class<?> getColumnClass(int c) {
return Product.class;
}
public void addItem(Product item) {
items.add( item );
fireTableRowsInserted( items.size(),
items.size() );
}
public void removeItem(int row) {
items.remove( row );
fireTableRowsDeleted( row,
row );
}
public List<Product> getItems() {
return items;
}
public void clear() {
int lastRow = items.size();
items.clear();
fireTableRowsDeleted( 0,
lastRow );
}
}
/**
*
* 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 static class CheckoutCallback {
KnowledgeBase kbase;
JTextArea output;
public CheckoutCallback(KnowledgeBase kbase) {
this.kbase = kbase;
}
public void setOutput(JTextArea output) {
this.output = output;
}
/**
* 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<Product> items) {
Order order = new Order();
//Iterate through list and add to cart
for ( Product p: items ) {
order.addItem( new Purchase( order, p ) );
}
//add the JFrame to the ApplicationData to allow for user interaction
StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession();
ksession.setGlobal( "frame",
frame );
ksession.setGlobal( "textArea",
this.output );
ksession.insert( new Product( "Gold Fish",
5 ) );
ksession.insert( new Product( "Fish Tank",
25 ) );
ksession.insert( new Product( "Fish Food",
2 ) );
ksession.insert( new Product( "Fish Food Sample",
0 ) );
ksession.insert( order );
ksession.fireAllRules();
//returns the state of the cart
return order.toString();
}
}
public static class Order {
private List<Purchase> items;
private double grossTotal = -1;
private double discountedTotal = -1;
private static String newline = System.getProperty( "line.separator" );
public Order() {
this.items = new ArrayList<Purchase>();
}
public void addItem(Purchase item) {
this.items.add( item );
}
public List<Purchase> getItems() {
return this.items;
}
public void setGrossTotal(double grossCost) {
this.grossTotal = grossCost;
}
public double getGrossTotal() {
return this.grossTotal;
}
public void setDiscountedTotal(double discountedCost) {
this.discountedTotal = discountedCost;
}
public double getDiscountedTotal() {
return this.discountedTotal;
}
public String toString() {
StringBuffer buf = new StringBuffer();
buf.append( "ShoppingCart:" + newline );
Iterator<Purchase> itemIter = getItems().iterator();
while ( itemIter.hasNext() ) {
buf.append( "\t" + itemIter.next() + newline );
}
// buf.append( "gross total=" + getGrossCost() + newline );
// buf.append( "discounted total=" + getDiscountedCost() + newline );
return buf.toString();
}
}
public static class Purchase {
private Order order;
private Product product;
public Purchase(Order order,
Product product) {
super();
this.order = order;
this.product = product;
}
public Order getOrder() {
return order;
}
public Product getProduct() {
return product;
}
public int hashCode() {
final int PRIME = 31;
int result = 1;
result = PRIME * result + ((order == null) ? 0 : order.hashCode());
result = PRIME * result + ((product == null) ? 0 : product.hashCode());
return result;
}
public boolean equals(Object obj) {
if ( this == obj ) return true;
if ( obj == null ) return false;
if ( getClass() != obj.getClass() ) return false;
final Purchase other = (Purchase) obj;
if ( order == null ) {
if ( other.order != null ) return false;
} else if ( !order.equals( other.order ) ) return false;
if ( product == null ) {
if ( other.product != null ) return false;
} else if ( !product.equals( other.product ) ) return false;
return true;
}
}
public static class Product {
private String name;
private double price;
public Product(String name,
double cost) {
this.name = name;
this.price = cost;
}
public String getName() {
return this.name;
}
public double getPrice() {
return this.price;
}
public String toString() {
return name + " " + this.price;
}
public int hashCode() {
final int PRIME = 31;
int result = 1;
result = PRIME * result + ((name == null) ? 0 : name.hashCode());
long temp;
temp = Double.doubleToLongBits( price );
result = PRIME * result + (int) (temp ^ (temp >>> 32));
return result;
}
public boolean equals(Object obj) {
if ( this == obj ) return true;
if ( obj == null ) return false;
if ( getClass() != obj.getClass() ) return false;
final Product other = (Product) obj;
if ( name == null ) {
if ( other.name != null ) return false;
} else if ( !name.equals( other.name ) ) return false;
if ( Double.doubleToLongBits( price ) != Double.doubleToLongBits( other.price ) ) return false;
return true;
}
}
}